Molecular self-assembly is extremely important in many fields, but the characterization of their corresponding intermolecular interactions is still lacking. The C-H stretching Raman band can reflect the hydrophobic in...Molecular self-assembly is extremely important in many fields, but the characterization of their corresponding intermolecular interactions is still lacking. The C-H stretching Raman band can reflect the hydrophobic interactions during the self-assembly process of sodium dodecyl sulfate （SDS） in aqueous solutions. However, the Raman spectra in this region are seriously overlapped by the OH stretching band of water. In this work, vertically polarized Raman spectra were used to improve the detection sensitivity of spectra of C-H region for the first time. The spectral results showed that the first critical micelle concentration and the second critical micelle concentration of SDS in water were 8.5 and 69 mmol/L, respectively, which were consistent with the results given by surface tension measurements. Because of the high sensitivity of vertically polarized Raman spectra, the critical micelle concentration of SDS in a relatively high concentration of salt solution could be obtained in our experiment. The two critical concentrations of SDS in 100 mmol/L NaCl solution were recorded to be 1.8 and 16.5 mmol/L, respectively. Through comparing the spectra and surface tension of SDS in water and in NaCl solution, the self-assembly process in bulk phase and at interface were discussed. The interactions among salt ions, SDS and water molecules were also analyzed. These results demonstrated the vertically polarized Raman spectra could be employed to study the self-assembly process of SDS in water.展开更多
Organic batteries have attracted a lot of attention due to the advantages of flexibility,light weight,vast resources,low cost,recyclability,and ease to be functionalized through molecular design.The biggest difference...Organic batteries have attracted a lot of attention due to the advantages of flexibility,light weight,vast resources,low cost,recyclability,and ease to be functionalized through molecular design.The biggest difference between organic materials and inorganic materials is the relatively weak intermolecular interactions in organic materials but strong covalent or ionic bonds in inorganic materials,which is the inherent reason of their different physiochemical and electrochemical characteristics.Therefore,the relatively weak intermolecular interactions can indisputably affect the electrochemical performance of organic batteries significantly.Herein,the intermolecular interactions that are closely related to organic redox-active materials and unique in organic batteries are summarized into three parts:1)between neighbor active molecules,2)between active molecules and the conduction additives,and 3)between active molecules and the binders.We hope this short review can give a distinct viewpoint for better understanding the internal reasons of high-performance batteries and stimulate the deep studies of relatively weak intermolecular interactions for strengthening the performance of organic batteries.展开更多
The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are var...The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are various weak intermolecular interactions in organic solids that sometimes have a large impact on the excited-state properties and energy dissipation pathways,resulting in strong fluorescence/phosphorescence.It is increasingly necessary to reveal the luminescence mechanism of organic solids.Here,we briefly review how intermolecular interactions induce strong normal fluorescence,thermally activate delayed fluorescence and room-temperature phosphorescence in organic solids by examining changes in geometry,electronic structures,electron-vibration coupling and energy dissipation dynamics of the excited states from isolated to aggregated molecules.We hope that the review will contribute to an in-depth understanding of the excited state properties of organic solids and to the design of excellent solid-state light-emitting materials.展开更多
The ultrasonic speeds,u and viscosities,ηof the binary mixtures of methyl acrylate with benzene,toluene,o-xylene,m-xylene,p-xylene,and mesitylene over the whole mole fraction range were measured at six different temp...The ultrasonic speeds,u and viscosities,ηof the binary mixtures of methyl acrylate with benzene,toluene,o-xylene,m-xylene,p-xylene,and mesitylene over the whole mole fraction range were measured at six different temperatures and at atmospheric pressure.From the experimental data,the excess isentropic compressibility,κ_(s)^(E),excess ultrasonic speed,u^(E),excess molar isentropic compressibility,K_(s,m)^(E),excess specific impedance,Z^(E)and deviations in viscosity,Δηhave been calculated.The partial molar isentropic compressions,K_(s,m,1) and K_(s,m,2),and excess partial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E) over the whole composition range,partial molar isentropic compressions,K_(s,m,1)^(-)and K_(s,m,2)^(-),and excesspartial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E)of the components at infinite dilution have also been calculated.The results specified the existence of weak interactions between unlike molecules,and these interactions follow the order:benzene>toluene>p-xylene>m-xylene>o-xylene>mesityle ne.The magnitude of interactions was found to be dependent on the number and position of the methyl groups in these aromatic hydrocarbons.展开更多
Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-p...Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.展开更多
Intermolecular interactions and properties of TNT（2,4,6-trinitrotoluene）/CL-20（2,4,6,8,10,12-hexanitrohexaazaisowurtzitane） cocrystal were studied by density functional theory（DFT） methods. Binding energy, natur...Intermolecular interactions and properties of TNT（2,4,6-trinitrotoluene）/CL-20（2,4,6,8,10,12-hexanitrohexaazaisowurtzitane） cocrystal were studied by density functional theory（DFT） methods. Binding energy, natural bond orbital（NBO）, and atom in molecules（AIM） analysis were performed to investigate the intermolecular interactions in the cocrystal. Results show that the unconventional CH···O type hydrogen bond plays a key role in forming the cocrystal. The variation tendency of entropy and enthalpy shows that the formation of the cocrystal is an exothermic process and low temperature will be benefit for the assembling of complexes. The calculated detonation velocity of the cocrystal agrees well with the experimental value which is higher than that of the physical mixture of TNT and CL-20. In addition, bond dissociation energies（BDEs） of the weakest trigger bond in TNT/CL-20 complex were calculated and the results show that the TNT/CL-20 complex is thermally stable. Finally, first-principles calculations were performed and analysis of the nitro group Mulliken charge indicates that the cocrystal is less sensitive than pure CL-20.展开更多
Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed ...Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed to reveal the origin of the interaction.The intermolecular interaction energy was evaluated with basis set superposition error correction（BSSE） and zero point energy correction（ZPEC）.The B3LYP/6-31G（d） calculations on the five complexes have shown that the greatest interaction（–13.98 kJ/mol） is found in the complex between HMX and hexa-aza-calix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine.The results have indicated that intermolecular interaction energies of aza-calix[6]arenes with substituted group are stronger than those without substituted group,and those with amido are greater than with nitryl.Thus,hexa-azacalix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine is rather equal to eliminate HMX from explosive waste water.展开更多
Tetrazole monomers （Ⅰ, Ⅱ） and all of their possible stable dimers （1, 2, 3, 4, 5, 6, 7 and 8） were fully optimized by DFT method at the B3LYP/6-311＋＋G^＊＊ level. Among the eight dimers, there were two 1H-tetr...Tetrazole monomers （Ⅰ, Ⅱ） and all of their possible stable dimers （1, 2, 3, 4, 5, 6, 7 and 8） were fully optimized by DFT method at the B3LYP/6-311＋＋G^＊＊ level. Among the eight dimers, there were two 1H-tetrazole dimers, three 2H-tetrazole dimers and three hetero dimers of 1H-tetrazole and 2H-tetrazole. Vibrational frequencies were calculated to ascertain that each structure was stable （no imaginary frequencies）. The basis set superposition errors （BSSE） are 2.78, 2.28, 2.97, 2.75, 2.74, 2.18, 1.23 and 3.10 kJ/mol, and the zero point energy （ZPE） corrections for the interaction energies are 4.88, 4.18, 3.87, 3.65, 3.54, 3.22, 2.87 and 4.34 kJ/mol for 1, 2, 3, 4, 5, 6, 7 and 8, respectively. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of the dimers is -43.71 kJ/mol. The charge redistribution mainly occurs on the adjacent N-H…N atoms between submolecules. The charge transfer between two subsystems is very small. Natural bond orbital （NBO） analysis was performed to reveal the origin of the interaction. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities （C^0P）, entropies （S^0T） and thermal corrections to enthalpy （H^0T）, and the changes of thermodynamic properties from monomer to dimer in the temperature range of 200.00 K to 700 K have been obtained. 1H-tetrazole monomer can spontaneously turn into two stable dimers at 298.15 K.展开更多
Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3...Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3LYP/6-311＋＋G＊＊ level. The maximum intermolecular interaction energy is -35.42 kJ/mol via the basis set superposition error-correction （BSSE） and zero point energy-correction （ZPE）. Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds＇ strength rather than their number. The dimerization processes of Ⅳ, Ⅴand Ⅵ can occur spontaneously at 200 K.展开更多
In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visi...In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visible(UV-Vis)spectroscopy was utilized for structure characterization.Moreover,to understand the reinforcing mechanism between ZnO and TNT,quantum chemistry and molecular dynamics simulation were undertaken to investigate the intermolecular interaction and mechanical properties.It is concluded that with 2.85 wt%ZnO nanoparticle addition,the amount of voids and defects decreases with the increase in bulk and shear modulus.The modified TNT/ZnO composite has high heat of formation,negative oxygen balance,and good detonation properties,which is expected to be a candidate for high-energy blended explosives.展开更多
Geometries, interaction energies and electronic properties for four types of dimers（hydrogen bonded, halogen bonded, π-halogen bonded, and ~r-hydrogen bonded） between HCCF and HCCR（R=F, CI, Br） were studied via M...Geometries, interaction energies and electronic properties for four types of dimers（hydrogen bonded, halogen bonded, π-halogen bonded, and ~r-hydrogen bonded） between HCCF and HCCR（R=F, CI, Br） were studied via MP2/6-31 1＋＋G（d,p） ab initio calculation. It is shown that the strength of the zr-hydrogen bonded dimers turns out to be greater than those of the other three types of dimers, with the interaction energies --4.611 kJ/mol for HCCF-HCCF, -4.700 kJ/mol for HCCF-HCCC1, and -4.850 kJ/mol for HCCF-HCCBr respectively at the CCSD（T）/6-311＋＋ G（d,p）//MP2/6-31 1＋＋G（d,p） level. In an effort to understand the nature of the intermolecular interactions prevalent in these dimers, the interaction energies were decomposed into physically distinct energy components with the aid of the symmetry adapted perturbation theory（SAPT）. The dispersion force is found to be the main origin of the intermolecular interactions in hydrogen bonded and halogen bonded dimers. In the π-halogen bonded system, the dispersion is the major bonding force in HCCF-HCCF and HCCF-HCCC1, while the induction energy is the most important component in HCCF-HCCBr. However, both the dispersion and electrostatic energy play a key role in π-hydrogen bonded dimers.展开更多
Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with ...Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with basis set superposition error （BSSE） and zero point energy （ZPE） correction. The nature of intermolecular interaction has been revealed by the analysis of AIM and NBO. The results indicate that the greatest binding energy of urea nitrate with RDX is –82.47kJ/mol. The O–H…O and N–H…O hydrogen bonds are important intermolecular interactions of urea nitrate cation with RDX, and the origin of hydrogen bonds is the oxygen atom offering its lone-pair electrons to the σ（O-H）＊ or σ（O-H）＊ antibonding orbital. The intermolecular interactions strengthen the N–NO2 bond, leading to the reduced sensitivity of urea nitrate and RDX mixture explosive.展开更多
Six fully optimized structures of the aza-calix[2]arene[2]-triazines/RDX supramo-lecular complexes have been obtained at the DFT-B3LYP/6-311＋＋G＊＊ level,and the corresponding intermolecular interactions have been i...Six fully optimized structures of the aza-calix[2]arene[2]-triazines/RDX supramo-lecular complexes have been obtained at the DFT-B3LYP/6-311＋＋G＊＊ level,and the corresponding intermolecular interactions have been investigated using the B3LYP,mPWPW91 and MP2 methods at the 6-311＋＋G＊＊ level,respectively.The natural bond orbital（NBO） and atoms in molecules（AIM） analyses have been performed to reveal the origin of interactions.To our interest,the result indicates that the strongest interaction is up to-22.34 kJ/mol after basis set superposition error（BSSE） and zero point energy（ZPE） correction at the MP2/6-311＋＋G＊＊ level.Furthermore,the intermolecular interactions between aza-calix[2]arene[2]-triazines with the substituted amidos and RDX are stronger than those of other complexes.Thus,the complexes with amidos can be used as the candidates to increase the stability of explosive and eliminate the explosive wastewater.展开更多
Small molecule donor/polymer acceptor(SMD/PA)solar cells demonstrate high stability and notable performance advantages due to reduced molecular weight distribution variability,indicating potential breakthroughs in pow...Small molecule donor/polymer acceptor(SMD/PA)solar cells demonstrate high stability and notable performance advantages due to reduced molecular weight distribution variability,indicating potential breakthroughs in power conversion efficiency(PCE).However,research in this area is limited.This manuscript synthesizes two novel small donor molecules,DTBDT-C1-D6 and DTBDT-C3-D6(DTBDT represents dithieno[2,3-d:2’,3’-d’]benzo[1,2-b:4,5-b’]dithiophene,C3 denotes a three-carbon spacer between the alkyl chain’s branching point and the core linkage site,C1 denotes a onecarbon spacer between the alkyl chain’s branching point and the core linkage site,and D6 representπbridge has two alkyl chains with six carbon atoms each),combined additives of chloronaphthalene(CN),to investigate their effects on packing properties,film formation dynamics,and device performance.Interestingly,the CN significantly impact the packing modes and ability of the donors,and ultimately the intermolecular interaction and the dynamics of film forming,making the device performance fluctuate wildly with the CN ratio.The DTBDT-C3-D6 molecule,with alkyl chains branching away from the donor core,with 1%CN in volume,forms an interpenetrating framework by the proper hetero/homo molecular interaction,promoting a PCE of 13.4%,significantly exceeding the 5.65%of the DTBDT-C1-D6 blend and also other CN volume ratios.This PCE is the highest reported for SMD/PA-type organic solar cells(OSCs).The findings highlight the importance of alkyl side chain branching and additives in modulating intermolecular interactions and film dynamics,offering insights into morphology control in OSCs.展开更多
Precisely controlling bulk heterojunction (BHJ)morphology through molecular design is one of the main long-standing challenges in developing high-performance organicsolar cells (OSCs). Herein, three small molecule acc...Precisely controlling bulk heterojunction (BHJ)morphology through molecular design is one of the main long-standing challenges in developing high-performance organicsolar cells (OSCs). Herein, three small molecule acceptors(SMAs) with different side chains (methyl, 2-ethylhexyl, and2-decyl tetradecyl on benzotriazole unit), namely R-M, R-EH,R-DTD, were designed and synthesized. Such side-chain en-gineering can effectively modulate the intermolecular inter-actions between acceptor/acceptor (A/A) and donor/A (D/A)molecules, thereby fine-tuning the bulk microstructures ofBHJ active layer systems. Compared with R-M and R-DTD,R-EH shows stronger A/A and D/A interactions with donorPM6, which delivers improved BHJ networks with bettermolecular ordering, enhancing charge transport and extrac-tion properties. Consequently, PM6:R-EH not only performs acompetitive device efficiency of over 18% but also exhibitsexcellent operation stability without obvious degradation be-haviors among the three systems. This study deepens the sy-nergistic effects of A/A and D/A interactions on BHJmorphology to achieve industrially viable OSCs with highdevice efficiency and stability.展开更多
Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the c...Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the capacity.While the molecular construct usually has a fixed dimension,whether its inter-molecular space could be self-adjustable during CO_(2)capture and release,behaving as a balloon,has captured imagination.Here we report a flexible intermolecular space of the double chain structure of self-assembled 1,4-pheny-lene diisocyanide(PDI)molecules on Ag(110)surface,which dynamically broadens and recovers during the CO_(2)capture and release.The incipient PDI double chains organize along the[001]direction of Ag(110),in which individual PDI molecules stand up in a zigzag order with the interchain width defined by twice the Ag lattice distance along_([110])direction(2α_([110])).When CO_(2)molecules are introduced,they assemble to occupy the interchain spaces,expanding the interchain width to 3α_([110]),4α_([110])and 5α_([110]):Warming up the sample leads to the thermally-driven CO_(2)desorption that recovers the original interchain space.High-resolution scanning tunneling microscopy(STM)jointly with density functional theory(DFT)calculations determine the structural and electronic interactions of CO_(2)molecules with the dynamical PDI structures,providing a molecular-level perspective for the design of a self-adjustable metal-organic construct for reversible gas capture and release.展开更多
One effective approach to strike the balance between ionic conductivity and mechanical strength in polymer electrolytes involves the design of a coupled polymer molecular structure comprising both rigid and flexible p...One effective approach to strike the balance between ionic conductivity and mechanical strength in polymer electrolytes involves the design of a coupled polymer molecular structure comprising both rigid and flexible phases.Nevertheless,the regulation of intermolecular interactions between plasticizers and rigid and flexible phases has been largely overlooked.Here,an intermolecular interaction engineering strategy is carried out with well-chosen dual-plasticize within qua si-sol id-state polymer electrolytes(QSPEs).Succinonitrile exhibits a stronger affinity towards rigid phase hydrogenated nitrile butadiene rubber(HNBR),while propene carbonate demonstrates a stronger affinity towards flexible segments poly(propylene carbonate)(PPC).This tailored intermolecular interaction engineering allows for differential plasticization of the polymer's rigid and flexible phases,thereby achieving a balance between ionic conductivity and mechanical strength.The QSPE have both higher ionic conductivity(1.04×10^(-4)S cm^(-1)at 30℃),t_(Li+)(0.55),and tensile strength(0.76 MPa).Li//Li symmetric cells maintaining performance over1100 h at 0.1 mA cm^(-2)and Li//LiFePO_(4)cells retaining 85.0%capacity after 700 cycles at 1.0 C.It is a unique angle to employ intermolecular interaction engineering in QSPEs through dual-plasticizer approach combined with CO_(2)-based polymer materials.This sustainable strategy combining dual-plasticizer engineering with CO_(2)-based polymers,offers insights for designing high-performance,eco-friendly lithium metal batteries.展开更多
Ultralong organic phosphorescence(UOP)materials have received considerable attention in the field of organic optoelectronics due to their long lifetime,high exciton utilization,large Stokes shift,and so on.Great advan...Ultralong organic phosphorescence(UOP)materials have received considerable attention in the field of organic optoelectronics due to their long lifetime,high exciton utilization,large Stokes shift,and so on.Great advancements have been achieved through manipulating intermolecular interactions for high-performance UOP materials in recent years.This review will discuss the influence of various intermolecular interactions,includingπ-πinteractions,n-πinteractions,halogen bonding,hydrogen bonding,coordinative bonding,and ionic bonding on phosphorescent properties at room temperature,respectively.We summarize the rule of manipulating intermolecular interactions for UOP materials with superior phosphorescent properties.This review will provide a guideline for developing new UOP materials with superior phosphorescent properties for potential applications in organic electronics and bioelectronics.展开更多
Asymmetric nonfullerene acceptors(NFAs)possess larger dipole moments and stronger intermolecular bonding energy than their symmetric counterparts thereby making them promising candidates for high-performance polymer s...Asymmetric nonfullerene acceptors(NFAs)possess larger dipole moments and stronger intermolecular bonding energy than their symmetric counterparts thereby making them promising candidates for high-performance polymer solar cells(PSCs).Herein,we report twoefficient acceptor–donor–acceptor(A–D–A)type NFAs(M14 and M18)with asymmetric side chains that show enhanced intermolecular interactions compared with their corresponding counterparts(M17 and M19)based on symmetric side chains.Furthermore,M14 and M18 exhibit elevated lowest unoccupiedmolecular orbitals and smallerπ–πstacking distances in comparison with M17 and M19,respectively.In combination with the benchmark polymer donor of PM6,the PM6:M14 blend affords superior charge transport properties,and more importantly,an increased power conversion efficiency(PCE)of 15.49%in comparison with the M17-based counterpart(13.01%PCE).Similarly,the asymmetric M18-based blend also shows a higher PCE of 13.00%than the M19-based blend(11.55%).Through further interface engineering,the bestperforming M14-based device delivers an enhanced PCE of 16.46%,which represents a record value among all asymmetric A–D–A type NFAs.Our results provide new insights into the design of asymmetric NFAs with enhanced intermolecular interactions for highperformance PSCs.展开更多
Ab initio SCF and Moller-Plesset correlation correction methods incombination with counterpoise procedure for BSSE correction have been applied to the theroeticalstudying of dimethylnitroamine and its dimers and trime...Ab initio SCF and Moller-Plesset correlation correction methods incombination with counterpoise procedure for BSSE correction have been applied to the theroeticalstudying of dimethylnitroamine and its dimers and trimers. Three optimized stable dimers and twotrimers have been obtained. The corrected binding energies of the most stable dimer and trimer werepredicted to be - 24.68 kJ/mol and - 47.27 kJ/mol, respectively at the MP2/6-31G ~*//HF/6-31G~*level. The proportion of correlated interaction energies to their total interaction energies for allclusters was at least 29.3 percent, and the BSSE of ΔE(MP2) was at least 10.0 kJ/mol. Dispersionand/ or electrostatic force were dominant in all clusters. There exist cooperative effects in boththe chain and the cyclic trimers. The vibrational frequencies associated with N―O stretches or wagsexhibit slight red shifts, but the modes associated with the motion of hydrogen atoms of the methylgroup show somewhat blue shifts with respect to those of monomer. Thermodynamic properties ofdimethylnitroamine and its clusters at different temperatures have been calculated on the basis ofvibrational analyses. The changes of the Gibbs free energies for the aggregation from monomer to themost stable dimer and trimer were predicted to be 14.37 kJ/mol and 30.40 kJ/mol, respectively, at 1atm and 298.15 K.展开更多
基金This work is supported by the National Natural Science Foundation of China （No.21473171 and No.21573208）, the Pundamental Research Funds for the Central Universities （No.JB160508）, and the Huashan Mountain Scholar Program.
文摘Molecular self-assembly is extremely important in many fields, but the characterization of their corresponding intermolecular interactions is still lacking. The C-H stretching Raman band can reflect the hydrophobic interactions during the self-assembly process of sodium dodecyl sulfate （SDS） in aqueous solutions. However, the Raman spectra in this region are seriously overlapped by the OH stretching band of water. In this work, vertically polarized Raman spectra were used to improve the detection sensitivity of spectra of C-H region for the first time. The spectral results showed that the first critical micelle concentration and the second critical micelle concentration of SDS in water were 8.5 and 69 mmol/L, respectively, which were consistent with the results given by surface tension measurements. Because of the high sensitivity of vertically polarized Raman spectra, the critical micelle concentration of SDS in a relatively high concentration of salt solution could be obtained in our experiment. The two critical concentrations of SDS in 100 mmol/L NaCl solution were recorded to be 1.8 and 16.5 mmol/L, respectively. Through comparing the spectra and surface tension of SDS in water and in NaCl solution, the self-assembly process in bulk phase and at interface were discussed. The interactions among salt ions, SDS and water molecules were also analyzed. These results demonstrated the vertically polarized Raman spectra could be employed to study the self-assembly process of SDS in water.
基金financialy supported by the National Natural Science Foundation of China(51773071)the National 1000-Talents Program+2 种基金Innovation Fund of WNLOthe Fundamental Research Funds for the Central Universities(HUST:2017KFYXJJ023,2017KFXKJC002,2018KFYXKJC018,and 2019kfy RCPY099)Hubei Provincial Natural Science Foundation of China(2019CFA002)
文摘Organic batteries have attracted a lot of attention due to the advantages of flexibility,light weight,vast resources,low cost,recyclability,and ease to be functionalized through molecular design.The biggest difference between organic materials and inorganic materials is the relatively weak intermolecular interactions in organic materials but strong covalent or ionic bonds in inorganic materials,which is the inherent reason of their different physiochemical and electrochemical characteristics.Therefore,the relatively weak intermolecular interactions can indisputably affect the electrochemical performance of organic batteries significantly.Herein,the intermolecular interactions that are closely related to organic redox-active materials and unique in organic batteries are summarized into three parts:1)between neighbor active molecules,2)between active molecules and the conduction additives,and 3)between active molecules and the binders.We hope this short review can give a distinct viewpoint for better understanding the internal reasons of high-performance batteries and stimulate the deep studies of relatively weak intermolecular interactions for strengthening the performance of organic batteries.
基金supported by the National Natural Science Foundation of China(No.21973099)。
文摘The organic solid-state lightemitting materials have attracted more and more attention owing to their promising applications in displays,lasers and optical communications.In contrast to isolated molecule,there are various weak intermolecular interactions in organic solids that sometimes have a large impact on the excited-state properties and energy dissipation pathways,resulting in strong fluorescence/phosphorescence.It is increasingly necessary to reveal the luminescence mechanism of organic solids.Here,we briefly review how intermolecular interactions induce strong normal fluorescence,thermally activate delayed fluorescence and room-temperature phosphorescence in organic solids by examining changes in geometry,electronic structures,electron-vibration coupling and energy dissipation dynamics of the excited states from isolated to aggregated molecules.We hope that the review will contribute to an in-depth understanding of the excited state properties of organic solids and to the design of excellent solid-state light-emitting materials.
文摘The ultrasonic speeds,u and viscosities,ηof the binary mixtures of methyl acrylate with benzene,toluene,o-xylene,m-xylene,p-xylene,and mesitylene over the whole mole fraction range were measured at six different temperatures and at atmospheric pressure.From the experimental data,the excess isentropic compressibility,κ_(s)^(E),excess ultrasonic speed,u^(E),excess molar isentropic compressibility,K_(s,m)^(E),excess specific impedance,Z^(E)and deviations in viscosity,Δηhave been calculated.The partial molar isentropic compressions,K_(s,m,1) and K_(s,m,2),and excess partial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E) over the whole composition range,partial molar isentropic compressions,K_(s,m,1)^(-)and K_(s,m,2)^(-),and excesspartial molar isentropic compressions,K_(s,m,1)^(-E) and K_(s,m,2)^(-E)of the components at infinite dilution have also been calculated.The results specified the existence of weak interactions between unlike molecules,and these interactions follow the order:benzene>toluene>p-xylene>m-xylene>o-xylene>mesityle ne.The magnitude of interactions was found to be dependent on the number and position of the methyl groups in these aromatic hydrocarbons.
基金support from the National Natural Science Foundation of China(Nos.52120105007,51834010)the National Science Fund for Distinguished Young Scholars(No.52222403).
文摘Fracturing fluid property play a critical role in developing unconventional reservoirs.Deep eutectic solvents(DESs)show fascinating potential for property improvement of clean fracturing fluids(CFFs)due to their low-price,low-toxicity,chemical stability and flexible designability.In this work,DESs were synthesized by mixing hydrogen bond acceptors(HBAs)and a given hydrogen bond donor(HBD)to explore their underlying influence on CFF properties based on the intermolecular interactions.The hydrogen-bonding,van der Waals and electrostatic interactions between DES components and surfactants improved the CFF properties by promoting the arrangement of surfactants at interface and enhancing the micelle network strength.The HBD enhanced the resistance of CFF for Ca^(2+) due to coordination-bonding interaction.The DESs composed of choline chloride(ChCl)and malonic acid show great enhancement for surface,rheology,temperature resistance,salt tolerance,drag reduction,and gel-breaking performance of CFFs.The DESs also improved the gel-breaking CFF-oil interactions,increasing the imbibition efficiencies to 44.2%in 74 h.Adjusting HBAs can effectively strengthen the intermolecular interactions(e.g.,HBA-surfactant and HBD-surfactant interactions)to improve CFF properties.The DESs developed in this study provide a novel strategy to intensify CFF properties.
文摘Intermolecular interactions and properties of TNT（2,4,6-trinitrotoluene）/CL-20（2,4,6,8,10,12-hexanitrohexaazaisowurtzitane） cocrystal were studied by density functional theory（DFT） methods. Binding energy, natural bond orbital（NBO）, and atom in molecules（AIM） analysis were performed to investigate the intermolecular interactions in the cocrystal. Results show that the unconventional CH···O type hydrogen bond plays a key role in forming the cocrystal. The variation tendency of entropy and enthalpy shows that the formation of the cocrystal is an exothermic process and low temperature will be benefit for the assembling of complexes. The calculated detonation velocity of the cocrystal agrees well with the experimental value which is higher than that of the physical mixture of TNT and CL-20. In addition, bond dissociation energies（BDEs） of the weakest trigger bond in TNT/CL-20 complex were calculated and the results show that the TNT/CL-20 complex is thermally stable. Finally, first-principles calculations were performed and analysis of the nitro group Mulliken charge indicates that the cocrystal is less sensitive than pure CL-20.
文摘Five fully optimized structures of complexes between aza-calix[6]arene host monomers（Ma～Me） and complexes（a～e） have been obtained at the B3LYP/6-31G（d） level.Natural bond orbital（NBO） analysis was performed to reveal the origin of the interaction.The intermolecular interaction energy was evaluated with basis set superposition error correction（BSSE） and zero point energy correction（ZPEC）.The B3LYP/6-31G（d） calculations on the five complexes have shown that the greatest interaction（–13.98 kJ/mol） is found in the complex between HMX and hexa-aza-calix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine.The results have indicated that intermolecular interaction energies of aza-calix[6]arenes with substituted group are stronger than those without substituted group,and those with amido are greater than with nitryl.Thus,hexa-azacalix[3]-p-tri-arene[3]-2-amido-1,3,5-tri-azine is rather equal to eliminate HMX from explosive waste water.
文摘Tetrazole monomers （Ⅰ, Ⅱ） and all of their possible stable dimers （1, 2, 3, 4, 5, 6, 7 and 8） were fully optimized by DFT method at the B3LYP/6-311＋＋G^＊＊ level. Among the eight dimers, there were two 1H-tetrazole dimers, three 2H-tetrazole dimers and three hetero dimers of 1H-tetrazole and 2H-tetrazole. Vibrational frequencies were calculated to ascertain that each structure was stable （no imaginary frequencies）. The basis set superposition errors （BSSE） are 2.78, 2.28, 2.97, 2.75, 2.74, 2.18, 1.23 and 3.10 kJ/mol, and the zero point energy （ZPE） corrections for the interaction energies are 4.88, 4.18, 3.87, 3.65, 3.54, 3.22, 2.87 and 4.34 kJ/mol for 1, 2, 3, 4, 5, 6, 7 and 8, respectively. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of the dimers is -43.71 kJ/mol. The charge redistribution mainly occurs on the adjacent N-H…N atoms between submolecules. The charge transfer between two subsystems is very small. Natural bond orbital （NBO） analysis was performed to reveal the origin of the interaction. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities （C^0P）, entropies （S^0T） and thermal corrections to enthalpy （H^0T）, and the changes of thermodynamic properties from monomer to dimer in the temperature range of 200.00 K to 700 K have been obtained. 1H-tetrazole monomer can spontaneously turn into two stable dimers at 298.15 K.
基金Project of National Natural Science Foundation of China (No. 10576030, 20173028)
文摘Seven optimized configurations and their electronic structures of 4-amino-5-nitro- 1,2,3-triazole dimers on their potential energy surface have been obtained by using density functional theory （DPT） method at the B3LYP/6-311＋＋G＊＊ level. The maximum intermolecular interaction energy is -35.42 kJ/mol via the basis set superposition error-correction （BSSE） and zero point energy-correction （ZPE）. Charge transfers between the two subsystems are small. The vibration analysis of optimized configurations was performed, and the thermodynamic property changes from monomer to dimer have been obtained with the temperature ranging from 200 to 800 K on the basis of statistical thermodynamics. It is found that the hydrogen bonds contribute to the dimers dominantly, and the extent of intermolecular interaction is mainly determined by the hydrogen bonds＇ strength rather than their number. The dimerization processes of Ⅳ, Ⅴand Ⅵ can occur spontaneously at 200 K.
基金financially supported by Joint Fund of the National Natural Science Foundation of China and China Academy of Engineering Physics(No.11076002)the National Natural Science Foundation of China(Nos.51373159 and 11402237)the Science and Technology Fund of China Academy of Engineering Physics(No.2015B0302055)。
文摘In this work,metal oxide nanoparticle ZnO was employed for the reinforcement of TNT.Scanning electronic microscopy(SEM)was used to study the microstructure on the fractured surface of TNT/nano-ZnO,and ultraviolet-visible(UV-Vis)spectroscopy was utilized for structure characterization.Moreover,to understand the reinforcing mechanism between ZnO and TNT,quantum chemistry and molecular dynamics simulation were undertaken to investigate the intermolecular interaction and mechanical properties.It is concluded that with 2.85 wt%ZnO nanoparticle addition,the amount of voids and defects decreases with the increase in bulk and shear modulus.The modified TNT/ZnO composite has high heat of formation,negative oxygen balance,and good detonation properties,which is expected to be a candidate for high-energy blended explosives.
基金Supported by the Scientific Research Fund of Hunan Provincial Education Department(No.B30865)Research Foundation of Hunan University of Science and Technology,China(No.E50814)
文摘Geometries, interaction energies and electronic properties for four types of dimers（hydrogen bonded, halogen bonded, π-halogen bonded, and ~r-hydrogen bonded） between HCCF and HCCR（R=F, CI, Br） were studied via MP2/6-31 1＋＋G（d,p） ab initio calculation. It is shown that the strength of the zr-hydrogen bonded dimers turns out to be greater than those of the other three types of dimers, with the interaction energies --4.611 kJ/mol for HCCF-HCCF, -4.700 kJ/mol for HCCF-HCCC1, and -4.850 kJ/mol for HCCF-HCCBr respectively at the CCSD（T）/6-311＋＋ G（d,p）//MP2/6-31 1＋＋G（d,p） level. In an effort to understand the nature of the intermolecular interactions prevalent in these dimers, the interaction energies were decomposed into physically distinct energy components with the aid of the symmetry adapted perturbation theory（SAPT）. The dispersion force is found to be the main origin of the intermolecular interactions in hydrogen bonded and halogen bonded dimers. In the π-halogen bonded system, the dispersion is the major bonding force in HCCF-HCCF and HCCF-HCCC1, while the induction energy is the most important component in HCCF-HCCBr. However, both the dispersion and electrostatic energy play a key role in π-hydrogen bonded dimers.
文摘Six fully optimized geometries of urea nitrate cation and RDX complexes have been obtained with DFT-B3LYP and MP2 methods at the 6-311＋＋G＊＊ level. The intermolecular interaction energies have been calculated with basis set superposition error （BSSE） and zero point energy （ZPE） correction. The nature of intermolecular interaction has been revealed by the analysis of AIM and NBO. The results indicate that the greatest binding energy of urea nitrate with RDX is –82.47kJ/mol. The O–H…O and N–H…O hydrogen bonds are important intermolecular interactions of urea nitrate cation with RDX, and the origin of hydrogen bonds is the oxygen atom offering its lone-pair electrons to the σ（O-H）＊ or σ（O-H）＊ antibonding orbital. The intermolecular interactions strengthen the N–NO2 bond, leading to the reduced sensitivity of urea nitrate and RDX mixture explosive.
文摘Six fully optimized structures of the aza-calix[2]arene[2]-triazines/RDX supramo-lecular complexes have been obtained at the DFT-B3LYP/6-311＋＋G＊＊ level,and the corresponding intermolecular interactions have been investigated using the B3LYP,mPWPW91 and MP2 methods at the 6-311＋＋G＊＊ level,respectively.The natural bond orbital（NBO） and atoms in molecules（AIM） analyses have been performed to reveal the origin of interactions.To our interest,the result indicates that the strongest interaction is up to-22.34 kJ/mol after basis set superposition error（BSSE） and zero point energy（ZPE） correction at the MP2/6-311＋＋G＊＊ level.Furthermore,the intermolecular interactions between aza-calix[2]arene[2]-triazines with the substituted amidos and RDX are stronger than those of other complexes.Thus,the complexes with amidos can be used as the candidates to increase the stability of explosive and eliminate the explosive wastewater.
基金the financial support provided by the National Natural Science Foundation of China(Nos.52303258,52321006,T2394480,and T2394484)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770200).
文摘Small molecule donor/polymer acceptor(SMD/PA)solar cells demonstrate high stability and notable performance advantages due to reduced molecular weight distribution variability,indicating potential breakthroughs in power conversion efficiency(PCE).However,research in this area is limited.This manuscript synthesizes two novel small donor molecules,DTBDT-C1-D6 and DTBDT-C3-D6(DTBDT represents dithieno[2,3-d:2’,3’-d’]benzo[1,2-b:4,5-b’]dithiophene,C3 denotes a three-carbon spacer between the alkyl chain’s branching point and the core linkage site,C1 denotes a onecarbon spacer between the alkyl chain’s branching point and the core linkage site,and D6 representπbridge has two alkyl chains with six carbon atoms each),combined additives of chloronaphthalene(CN),to investigate their effects on packing properties,film formation dynamics,and device performance.Interestingly,the CN significantly impact the packing modes and ability of the donors,and ultimately the intermolecular interaction and the dynamics of film forming,making the device performance fluctuate wildly with the CN ratio.The DTBDT-C3-D6 molecule,with alkyl chains branching away from the donor core,with 1%CN in volume,forms an interpenetrating framework by the proper hetero/homo molecular interaction,promoting a PCE of 13.4%,significantly exceeding the 5.65%of the DTBDT-C1-D6 blend and also other CN volume ratios.This PCE is the highest reported for SMD/PA-type organic solar cells(OSCs).The findings highlight the importance of alkyl side chain branching and additives in modulating intermolecular interactions and film dynamics,offering insights into morphology control in OSCs.
基金financially supported by the National Natural Science Foundation of China (NSFC) (22279094 and 223B2904)the Fundamental Research Funds for the Central Universities+1 种基金supported by the Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology, 2024-skllmd23)the support of the Opening Project of the Key Laboratory of Advanced Electrode Materials for Novel Solar Cells for Petroleum and Chemical Industry of China (2024A051)。
文摘Precisely controlling bulk heterojunction (BHJ)morphology through molecular design is one of the main long-standing challenges in developing high-performance organicsolar cells (OSCs). Herein, three small molecule acceptors(SMAs) with different side chains (methyl, 2-ethylhexyl, and2-decyl tetradecyl on benzotriazole unit), namely R-M, R-EH,R-DTD, were designed and synthesized. Such side-chain en-gineering can effectively modulate the intermolecular inter-actions between acceptor/acceptor (A/A) and donor/A (D/A)molecules, thereby fine-tuning the bulk microstructures ofBHJ active layer systems. Compared with R-M and R-DTD,R-EH shows stronger A/A and D/A interactions with donorPM6, which delivers improved BHJ networks with bettermolecular ordering, enhancing charge transport and extrac-tion properties. Consequently, PM6:R-EH not only performs acompetitive device efficiency of over 18% but also exhibitsexcellent operation stability without obvious degradation be-haviors among the three systems. This study deepens the sy-nergistic effects of A/A and D/A interactions on BHJmorphology to achieve industrially viable OSCs with highdevice efficiency and stability.
基金supported by the Innovation Program for Quantum Science and Technology(2021ZD0303302)the CAS Project for Young Scientists in Basic Research(YSBR-054)+2 种基金the National Natural Science Foundation of China(Nos.22425206,21972129)NSF grant CHE-2303197the New Cornerstone Science Foundation.
文摘Molecular constructs define the elementary units in porous materials for efficient CO_(2)capture.The design of appro-priate interpore and intermolecular space is crucial to stabilize CO_(2)molecules and maximize the capacity.While the molecular construct usually has a fixed dimension,whether its inter-molecular space could be self-adjustable during CO_(2)capture and release,behaving as a balloon,has captured imagination.Here we report a flexible intermolecular space of the double chain structure of self-assembled 1,4-pheny-lene diisocyanide(PDI)molecules on Ag(110)surface,which dynamically broadens and recovers during the CO_(2)capture and release.The incipient PDI double chains organize along the[001]direction of Ag(110),in which individual PDI molecules stand up in a zigzag order with the interchain width defined by twice the Ag lattice distance along_([110])direction(2α_([110])).When CO_(2)molecules are introduced,they assemble to occupy the interchain spaces,expanding the interchain width to 3α_([110]),4α_([110])and 5α_([110]):Warming up the sample leads to the thermally-driven CO_(2)desorption that recovers the original interchain space.High-resolution scanning tunneling microscopy(STM)jointly with density functional theory(DFT)calculations determine the structural and electronic interactions of CO_(2)molecules with the dynamical PDI structures,providing a molecular-level perspective for the design of a self-adjustable metal-organic construct for reversible gas capture and release.
基金supported by the National Key Research and Development Program(2019YFA0705701)National Natural Science Foundation of China(22075329,22008267,21978332 and 22179149)+1 种基金Research and Development Project of Henan Academy Sciences China(232018002)Guangdong Basic and Applied Basic Research Foundation(2021A1515010731)。
文摘One effective approach to strike the balance between ionic conductivity and mechanical strength in polymer electrolytes involves the design of a coupled polymer molecular structure comprising both rigid and flexible phases.Nevertheless,the regulation of intermolecular interactions between plasticizers and rigid and flexible phases has been largely overlooked.Here,an intermolecular interaction engineering strategy is carried out with well-chosen dual-plasticize within qua si-sol id-state polymer electrolytes(QSPEs).Succinonitrile exhibits a stronger affinity towards rigid phase hydrogenated nitrile butadiene rubber(HNBR),while propene carbonate demonstrates a stronger affinity towards flexible segments poly(propylene carbonate)(PPC).This tailored intermolecular interaction engineering allows for differential plasticization of the polymer's rigid and flexible phases,thereby achieving a balance between ionic conductivity and mechanical strength.The QSPE have both higher ionic conductivity(1.04×10^(-4)S cm^(-1)at 30℃),t_(Li+)(0.55),and tensile strength(0.76 MPa).Li//Li symmetric cells maintaining performance over1100 h at 0.1 mA cm^(-2)and Li//LiFePO_(4)cells retaining 85.0%capacity after 700 cycles at 1.0 C.It is a unique angle to employ intermolecular interaction engineering in QSPEs through dual-plasticizer approach combined with CO_(2)-based polymer materials.This sustainable strategy combining dual-plasticizer engineering with CO_(2)-based polymers,offers insights for designing high-performance,eco-friendly lithium metal batteries.
基金National Natural Science Foundation of China,Grant/Award Numbers:22105038,21912750Fujian Province Natural Science Foundation of China,Grant/Award Number:2022J01654Fujian Normal University Start-up Grant,Grant/Award Number:Y0720306K13。
文摘Ultralong organic phosphorescence(UOP)materials have received considerable attention in the field of organic optoelectronics due to their long lifetime,high exciton utilization,large Stokes shift,and so on.Great advancements have been achieved through manipulating intermolecular interactions for high-performance UOP materials in recent years.This review will discuss the influence of various intermolecular interactions,includingπ-πinteractions,n-πinteractions,halogen bonding,hydrogen bonding,coordinative bonding,and ionic bonding on phosphorescent properties at room temperature,respectively.We summarize the rule of manipulating intermolecular interactions for UOP materials with superior phosphorescent properties.This review will provide a guideline for developing new UOP materials with superior phosphorescent properties for potential applications in organic electronics and bioelectronics.
基金supported by the National Natural Science Foundation of China(nos.22101285,51873138,52130306,21734009,and 22075287)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(CAS)(no.QYZDB-SSW-SLH032)+2 种基金the China Postdoctoral Science Foundation(no.2021M703218)the Program of Youth Innovation Promotion Association CAS(no.2021000060)Beijing National Laboratory for Molecular Sciences(no.BNLMS201902).
文摘Asymmetric nonfullerene acceptors(NFAs)possess larger dipole moments and stronger intermolecular bonding energy than their symmetric counterparts thereby making them promising candidates for high-performance polymer solar cells(PSCs).Herein,we report twoefficient acceptor–donor–acceptor(A–D–A)type NFAs(M14 and M18)with asymmetric side chains that show enhanced intermolecular interactions compared with their corresponding counterparts(M17 and M19)based on symmetric side chains.Furthermore,M14 and M18 exhibit elevated lowest unoccupiedmolecular orbitals and smallerπ–πstacking distances in comparison with M17 and M19,respectively.In combination with the benchmark polymer donor of PM6,the PM6:M14 blend affords superior charge transport properties,and more importantly,an increased power conversion efficiency(PCE)of 15.49%in comparison with the M17-based counterpart(13.01%PCE).Similarly,the asymmetric M18-based blend also shows a higher PCE of 13.00%than the M19-based blend(11.55%).Through further interface engineering,the bestperforming M14-based device delivers an enhanced PCE of 16.46%,which represents a record value among all asymmetric A–D–A type NFAs.Our results provide new insights into the design of asymmetric NFAs with enhanced intermolecular interactions for highperformance PSCs.
文摘Ab initio SCF and Moller-Plesset correlation correction methods incombination with counterpoise procedure for BSSE correction have been applied to the theroeticalstudying of dimethylnitroamine and its dimers and trimers. Three optimized stable dimers and twotrimers have been obtained. The corrected binding energies of the most stable dimer and trimer werepredicted to be - 24.68 kJ/mol and - 47.27 kJ/mol, respectively at the MP2/6-31G ~*//HF/6-31G~*level. The proportion of correlated interaction energies to their total interaction energies for allclusters was at least 29.3 percent, and the BSSE of ΔE(MP2) was at least 10.0 kJ/mol. Dispersionand/ or electrostatic force were dominant in all clusters. There exist cooperative effects in boththe chain and the cyclic trimers. The vibrational frequencies associated with N―O stretches or wagsexhibit slight red shifts, but the modes associated with the motion of hydrogen atoms of the methylgroup show somewhat blue shifts with respect to those of monomer. Thermodynamic properties ofdimethylnitroamine and its clusters at different temperatures have been calculated on the basis ofvibrational analyses. The changes of the Gibbs free energies for the aggregation from monomer to themost stable dimer and trimer were predicted to be 14.37 kJ/mol and 30.40 kJ/mol, respectively, at 1atm and 298.15 K.
