The halogen and hydrogen bonding complexes and trihalomethanes （CHX3, X=C1, Br, I） are between 2,2,6,6-tetramethylpiperidine-noxyl simulated by computational quantum chem- istry. The molecular electrostatic potentia...The halogen and hydrogen bonding complexes and trihalomethanes （CHX3, X=C1, Br, I） are between 2,2,6,6-tetramethylpiperidine-noxyl simulated by computational quantum chem- istry. The molecular electrostatic potentials, geometrical parameters and interaction energy of halogen and hydrogen bonding complexes combined with natural bond orbital analysis are obtained. The results indicate that both halogen and hydrogen bonding interactions obey the order CI〈Br〈I, and hydrogen bonding is stronger than the corresponding halogen bond- ing. So, hydrogen bonding complexes should be dominant in trihalomethanes. However, it is possible that halogen bonding complex is competitive, even preponderant, in triiodomethane due to the similar interaction energy. This work might provide useful information on specific solvent effects as well as for understanding the mechanism of nitroxide radicals as a bioprobe to interact with the halogenated compounds in biological and biochemical fields.展开更多
Does the halogen bonding interaction co-exist in liquid when it competes with the hydrogen bonding interaction？ The classical molecular dynamics simulations for the solvation properties of CLF molecule in water are p...Does the halogen bonding interaction co-exist in liquid when it competes with the hydrogen bonding interaction？ The classical molecular dynamics simulations for the solvation properties of CLF molecule in water are performed with the Lennard-Jones plus Coulomb electrostatic potential parameters that are optimized with ab initio interaction energy calculations for the pre-reactive H2O-CLF complex. We find that the halogen bonding interactions occur between O and CL atoms and have the comparable strength and population with respect to the hydrogen bonding interactions of C1...H.展开更多
Controlling microstructure and thin film morphology of organic semiconductors by supramolecular arrangement is critical to improving their device performance. To realize well-controlling supramolecular assembly, a cor...Controlling microstructure and thin film morphology of organic semiconductors by supramolecular arrangement is critical to improving their device performance. To realize well-controlling supramolecular assembly, a core-expanded naphthalene diimides derivative （1） was designed and synthesized as an n-type organic semiconductor and also as a halogen bonding （XB） donor that could form complementary XBs with 2,2-dipyridine or 2,2-bipyrimidine acceptor. The XB interactions in the solid state of 1/2,2- dipyridine and 1/2,2-bipyrimidine were confirmed by a series of characterization methods, such as thermal gravimetric analysis （TGA）, X-ray photoelectron spectroscopy （XPS）, nuclear magnetic resonance （NMR） involving 13F NMR and solid-state 13C NMR. Organic field-effect transistors （OFETs） based on XB complexes 1/2,2-dipyridine or 1/2,2-bipyrimidine showed better device performance than that of devices based on pure 1, with the average electron mobility increased more than doubled （from 0.027cm2V-1 s-1 to 0.070cm2V-1 s-1）.展开更多
Whether the fluorine atom(F)can engage in a halogen bond(XB)has remained a subject of ongoing debate.The discovery of N-fluoropyridinium triflate as a unique"F-cation organocatalyst"for aziridine synthesis h...Whether the fluorine atom(F)can engage in a halogen bond(XB)has remained a subject of ongoing debate.The discovery of N-fluoropyridinium triflate as a unique"F-cation organocatalyst"for aziridine synthesis has generally been considered the first instance of F-halogen bonding catalysis.Nevertheless,the mechanistic details of this reaction have remained elusive,and compelling evidence supporting the F-halogen bond catalysis has been lacking.In this study,we present an in-depth computational investigation of the mechanism of this reaction to gain insights into the intriguing role of the F-cation organocatalyst.Our results,however,are inconsistent with the previous prevalent F-halogen bonding catalysis mechanism but instead,bring to light a new fluorine cation transfer mechanism.This novel mechanism is supported by control experiments and can explain the observed cis-trans selectivity.展开更多
Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treat...Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treatment of subcutaneous tumors.This study reports the exploration of novel supramolecular halogen-bonded organic frameworks(XOFs)based on[N…Br^(+)…N]halogen bonds through the ligand exchange strategy and their application in photothermal therapy.Through ligand exchange,XOF(Br)-TPy was successfully prepared,and its structure and properties were thoroughly characterized using NMR,XPS,FT-IR,and XRD techniques.Due to their cationic characteristics,these XOFs serve as effective carriers for the photothermal agent IR820.In vitro experiments demonstrated that the IR820@XOF(Br)-TPy composite exhibits excellent photothermal conversion efficiency under NIR irradiation,effectively inducing tumor cell ablation.Furthermore,in vivo studies confirmed the remarkable antitumor efficacy of the composite material in a subcutaneous tumor model.This work demonstrates that the ligand exchange strategy is a versatile and facile approach for constructing XOFs(Br)and provides a novel strategy for developing advanced photothermal therapeutic agents with significant application potential.展开更多
A series of complexes formed between halogen-containing molecules and ammonia have been investigated by means of the atoms in molecules （AIM） approach to gain a deeper insight into halogen bonding. The existence of ...A series of complexes formed between halogen-containing molecules and ammonia have been investigated by means of the atoms in molecules （AIM） approach to gain a deeper insight into halogen bonding. The existence of the halogen bond critical points （XBCP） and the values of the electron density （Pb） and Laplacian of electron density （V2pb） at the XBCP reveal the closed-shell interactions in these complexes. Integrated atomic properties such as charge, energy, polarization moment, volume of the halogen bond donor atoms, and the corresponding changes （△） upon complexation have been calculated. The present calculations have demonstrated that the halogen bond represents different AIM properties as compared to the well-documented hydrogen bond. Both the electron density and the Laplacian of electron density at the XBCP have been shown to correlate well with the interaction energy, which indicates that the topological parameters at the XBCP can be treated as a good measure of the halogen bond strength In addition, an excellent linear relationship between the interatomic distance d（X…N） and the logarithm of Pb has been established.展开更多
The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （EL...The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （ELF） in this paper. The calculated results show that the geometry of the halogen atom bonded at the N-atom is stable than those bonded at S- or C-atom. The molecular electrostatic potentials determine the geometries and stabilities of the complexes. The valence basin of the S- or N-atom in the electron-donating NCS radical is compressed and its population decreases during the process of formation of the halogen-bonded complexes.展开更多
Halogen bonding interactions between several halogenated ion pairs and CO2 molecules have been investigated by means of density functional theory calculations. To account for the influence of solvent environment, the ...Halogen bonding interactions between several halogenated ion pairs and CO2 molecules have been investigated by means of density functional theory calculations. To account for the influence of solvent environment, the implicit polarized continuum model was also employed. The bromide and iodide cations of ionic liquids (ILs) under study can interact with CO2 molecules via X O interactions, which become much stronger in strength than those in the complexes of iodo-perfluorobenzenes, very effective halogen bond donors, with CO2 molecules. Such interactions, albeit somewhat weaker in strength, are also observed between halogenated ion pairs and CO2 molecules. Thus, the solubility of CO2 may be improved when using halogenated ILs, as a result of the formation of X O halogen bonds. Under solvent effects, the strength of the interactions tends to be weakened to some degree, with a concomitant elongation of intermolecular distances. The results presented here would be very useful in the design and synthesis of novel and potent ILs for CO2 physical absorption.展开更多
Trans-5,10-bis(1-bromodifluoroacetyl-1-ethoxycarbonyl-methylidene)thianthrene (1b) was prepared from the reaction of BrCF2COC(N2)CO2Et with thianthrene. X-ray single crystal diffraction analysis showed that the inter-...Trans-5,10-bis(1-bromodifluoroacetyl-1-ethoxycarbonyl-methylidene)thianthrene (1b) was prepared from the reaction of BrCF2COC(N2)CO2Et with thianthrene. X-ray single crystal diffraction analysis showed that the inter-molecular halogen bonding and hydrogen bonding coexisted in this compound. The bromine atom acted as an elec-tron acceptor in the halogen bond and an electron donor in the hydrogen bond. It is the first example that the bro-mine atom acted as such a dual role in the hydrogen and halogen bond.展开更多
Ubiquitous competition of stereospecific E2 elimination versus SN2 substitution is of central importance in chemical synthesis.Herein,we uncover how the nature of the leaving group affects the intrinsic competing dyna...Ubiquitous competition of stereospecific E2 elimination versus SN2 substitution is of central importance in chemical synthesis.Herein,we uncover how the nature of the leaving group affects the intrinsic competing dynamics that remains largely unknown as opposed to its role in reactivity.Results are presented for a prototype case of fluoride anion reacting with ethyl chloride,compared to reacting with ethyl iodide.Chemical dynamics simulations reproduce scattering signatures observed in experiments and reveal that the direct stripping/rebound mechanisms characterize the E2/S_(N)2 reactions,in line with their dynamic fingerprints identified.Quite similar structures and energetics are found for the Cl^(−)and I^(−)leaving halides,whereas the competing dynamics show markedly distinct features.A halogen-bonding attraction is found to be crucial that modifies the interaction potential in the entrance channel and essentially tunes the underlying atomistic behaviors causing a mechanistic shift.This work highlights the dynamical effects induced by a leaving group on the proceedings of baseinduced elimination and nucleophilic substitution,providing a unique insight into the reaction selectivity for complex chemical networks and environments.展开更多
Efficient conversion and synergistic solar energy utilization are critical for advancing low-carbon and sustainable development.In this study,two Pt(Ⅱ)-based metal/halogen-bonded organic frameworks(MXOFBen and MXOF-A...Efficient conversion and synergistic solar energy utilization are critical for advancing low-carbon and sustainable development.In this study,two Pt(Ⅱ)-based metal/halogen-bonded organic frameworks(MXOFBen and MXOF-Anth)were designed to enhance photoconversion efficiency and enable multifunctional integration.The ligand L-terpyr is formed by coupling tripyridine with diphenylamine dipyridine,in which the tripyridine effectively acts as a metal-ligand to lower the band gap and promote nonradiative leaps,thereby enhancing the photoconversion ability.Meanwhile,diphenylamine dipyridine serves as a[N…I^(+)…N]halogen-bonding acceptor,imparting superhydrophilicity to the materials and increasing carrier density,further improving photocatalytic performance.Experimental results demonstrate that these two MXOFs achieve impressive interfacial water evaporation efficiencies of up to87.8%and 94.0%,respectively.Additionally,the materials exhibit excellent performance in photothermal power generation and photocatalysis of H_(2)O_(2).Notably,the MXOFs also deliver strong overall performance in integrated systems combining interfacial water evaporation with photothermal power generation or photocatalysis,underscoring their exceptional photoconversion efficiency and multifunctional potential.This work introduces a novel strategy by incorporating metal-ligand and halogen bonds,offering a pathway to enhance photoconversion efficiency and develop versatile materials for advanced solar energy applications,thereby fostering the progress of high-efficiency solar energy conversion and multifunctional organic materials.展开更多
Inverse halogen bonds interactions involving Br in the electronic deficiency systems of CH3＋...Br-Y （Y=H, CCH, CN, NC） have been investigated by B3LYP/6- 311＋＋G（d, p） and MP2/6-311＋＋G（d, p） methods. The cal...Inverse halogen bonds interactions involving Br in the electronic deficiency systems of CH3＋...Br-Y （Y=H, CCH, CN, NC） have been investigated by B3LYP/6- 311＋＋G（d, p） and MP2/6-311＋＋G（d, p） methods. The calculated interaction energies with basis set super-position error correction of the four IXBs complexes are 218.87, 219.48, 159.18, and 143.05kJ/mol （MP2/6-311＋＋G（d, p））, respectively. The relative stabilities of the four complexes increased in the order： CH3＋ … BrCN〈CH3＋…- BrNC〈CH3＋… BrH≈CH3＋ …BrCCH. Natural bond orbital theory analysis and the chemical shifts calculation of the related atoms revealed that the charges flow from Br-Y to CH3e. Here, the Br of Br-Y acts as both a halogen bond donor and an electron donor. Therefore, compared with conventional halogen bonds, the IXBs complexes formed between Br-Y and CH3＋. Atoms-in-molecules theory has been used to investigate the topological properties of the critical points of the four IXBs structures which have more covalent content.展开更多
Crystallization of[CuI(CNXyl)_(3)](1)with I_(2)(exhibiting strong halogen bond donor properties),at different molar ratios between the reactants,resulted in a series of(XylNC)Cu^(Ⅰ) crystal polyiodides formed along w...Crystallization of[CuI(CNXyl)_(3)](1)with I_(2)(exhibiting strong halogen bond donor properties),at different molar ratios between the reactants,resulted in a series of(XylNC)Cu^(Ⅰ) crystal polyiodides formed along with gradual accumulation of iodine,namely[Cu(I_(3))(CNXyl)_(3)](two crystalline polymorphs 2^(Ⅰ) and 2^(Ⅱ)),[Cu(I_(3))(CNXyl)_(3)]·1/2I_(2)(2·1/2 I_(2))and[Cu(CNXyl)_(3)](I_(5))(3);all these compounds were studied by X-ray diffractometry.Molecular electrostatic potential(MEP)surface plots were also calculated using density functional theory(DFT)for isolated molecules of 2 and I_(2),showing electrophilic and nucleophilic sites.Halogen bonding in 2·1/2 I_(2) was additionally elucidated for both crystal and cluster models,including combined quantum theory of atoms-in-molecules(QTAIM)and one-electron potential(OEP)projections.For model clusters,DFT energetic analysis,quantum theory of atoms-in-molecules,combined with the noncovalent interaction index plot(QTAIM/NCIplot),natural bond orbital(NBO)donor–acceptor charge transfer analysis,and Wiberg bond index(WBI)analysis were used.In the structure of 2·1/2I_(2),the presence of an I_(2)…I_(3)_(−)halogen bonded linkage gives a key toward the understanding of the precise mechanism for the generation of I_(5)^(−)(and then I_(8)^(2−))ligands from I_(2) and metal-coordinated I_(3)_(−).展开更多
In the structures of the isostructural cocrystals[Cu^(I)_(3)(CNXyl)_(3)]·CHX_(3)(X=Br,I),two adjacent Cu^(I)-bound isocyanide groups,whose carbon lone pairs are blocked by ligation,exhibit nucleophilic properties...In the structures of the isostructural cocrystals[Cu^(I)_(3)(CNXyl)_(3)]·CHX_(3)(X=Br,I),two adjacent Cu^(I)-bound isocyanide groups,whose carbon lone pairs are blocked by ligation,exhibit nucleophilic properties induced by aπ-donating d10[Cu^(I)]center and function as an integrated two-center halogen bond acceptor forming bifurcatedμ_(2)-X⋯(C,C)halogen bonds.展开更多
Copper has become a favored Pb-free candidate in the exploration of metal halide photoelectric materials;however,the known hybrid copper halides(HCHs)suffer from wide band gaps,low absorption coefficients or large exc...Copper has become a favored Pb-free candidate in the exploration of metal halide photoelectric materials;however,the known hybrid copper halides(HCHs)suffer from wide band gaps,low absorption coefficients or large exciton binding energies(E_(b)),hindering their application as photodetectors.Combining functional aryl thioether with copper halide in one crystal lattice is greatly desired.However,it is impeded by the intricate and environment-unfriendly multi-step organic synthesis of aryl thioether,which involves harsh reaction conditions,toxic organic reagents and noble metal catalysts.Herein,we report the first Cl…Cl halogen bonding(XB)assembled HCH conductive framework with aryl thioether as ligand,{bis(5-chloropyridin-2-yl)sulfane(CuI)}_(n)(BCS-CuI).It was obtained by a well-designed facile and sustainable“All-in-One”synthesis strategy,where aryl halides,noble metals and harsh reaction conditions are not involved.Property measurements and theoretical calculations disclose that the XB assembled three-dimensional framework contributes significantly to the physical properties of BCS-CuI,which exhibits a small band gap of 2.44 eV,strong optical absorption and a relatively small E_(b) value of 55.8 meV.Importantly,BCS-CuI exhibits great potential application as a hypotoxicity photodetector with a high photoresponse on/off ratio of 32.9 and carrier concentration and mobility superior to that of the wellknown methylamine lead iodide(CH_(3)NH_(3))PbI_(3).展开更多
The development of non-noble metal ions with potential organic phosphor ligands through strong coordination bonds can afford an effective platform for achieving persistent and tunable phosphorescence at room temperatu...The development of non-noble metal ions with potential organic phosphor ligands through strong coordination bonds can afford an effective platform for achieving persistent and tunable phosphorescence at room temperature.However,successful examples of coordination polymers(CPs)or metal-organic frameworks(MOFs)exhibiting long-lasting phosphorescence emission are still rarely explored.In this work,a new strategy has been used for the first time to achieve long-lasting phosphorescence via π-type halogen bonding in coordination polymers.By the selection of two isomers 5-BIPA and 4-BIPA with different Br atom substitution positions in isophthalic acid(IPA),two new Zn(Ⅱ)-based coordination polymers exhibiting long-lasting phosphorescence emission up to the order of magnitude of millisecond(ms)were presented,which were further revealed by theoretical calculations.Optoelectronic measurements indicated that 1 showed a high photoelectron response because the delocalized π-type halogen bonding and long range order ofπ-conjugated chains afforded large electron channels for efficient charge transport.展开更多
The syntheses and crystal structures of five new compounds containing the UO_(2)^(2+)cation,2,5-diiodobenzoic acid,and a chelating N-donor(2,2’-bipyridine(bipy)(1),1,10-phenanthroline(phen)(2 and 3),2,2’:6’,2’’-t...The syntheses and crystal structures of five new compounds containing the UO_(2)^(2+)cation,2,5-diiodobenzoic acid,and a chelating N-donor(2,2’-bipyridine(bipy)(1),1,10-phenanthroline(phen)(2 and 3),2,2’:6’,2’’-terpyridine(terpy)(4),or 4’-chloro-2,2’:6’,2’’-terpyridine(Cl-terpy)(5))are described and the spectroscopic properties(both vibrational and luminescent)and stretching and interaction force constants of complexes 2,4,and 5 are reported.Single crystal X-ray diffraction analysis of these materials shows that variation of the chelating N-donor with the same benzoic acid featuring multiple,polarizable halogens at the periphery allows for the systematic accessing of uranyl oxo atoms for non-covalent assembly,which is notable as these atoms are generally terminal.Spectroscopic characterization of complexes 2,4,and 5 indicate that oxo atom participation in halogen bonding interactions may complement the effects of the electron donating ability of the capping ligand on corresponding uranyl luminescence and vibrational spectra,each contributing to the observed bathochromic shifts.展开更多
Harnessing the nominally terminal oxo atoms of the linear uranyl(UO_(2)^(2+))cation represents a frontier within the field of f-element hybrid materials.Here we outline a route for systematically accessing uranyl oxo ...Harnessing the nominally terminal oxo atoms of the linear uranyl(UO_(2)^(2+))cation represents a frontier within the field of f-element hybrid materials.Here we outline a route for systematically accessing uranyl oxo atoms via judicious pairing with Ag^(+)cations or iodobenzoates,and describe the syntheses and crystal structures of four new heterometallic compounds containing Ag^(+)cations,the UO_(2)^(2+)cation,and o-(1),m-(2),p-iodo-(3),and 2,5-diiodo-(4)carboxylate ligands.Vibrational and luminescence spectroscopic properties for all four compounds are reported,as are computational findings from quantum chemical calculations and density-based quantum theory of atoms in molecules(QTAIM)analyses.Single crystal X-ray diffraction analysis of compounds 1–4 shows that the nominally terminal uranyl oxo atoms are engaged in either covalent UO_(2)–Ag cation–cation interactions(1 and 3)or non-covalent assembly via halogen bonding interactions(2 and 4).Raman,infrared(IR),and luminescence spectra of 1–4 are redshifted with respect to the free uranyl cation indicating that both halogen–oxo and cation–cation interactions weaken the U[double bond,length as m-dash]O bond,and in the case of 3 we note a rare example of activation of the uranyl asymmetric stretch(ν_(3))in the Raman spectra,likely due to the Ag–oxo cation–cation interaction lowering the symmetry of the uranyl cation.Quantum chemical calculations and QTAIM analysis highlight a quantitative difference between halogen bonds and cation–cation interactions,with the latter shown to significantly decrease uranyl bond orders and electron density at bond critical points.展开更多
The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule...The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule （referring to dichloromethane, chloroform and acetonitrile）, can be formed in solution. The strength of halogen and hydrogen bonds in the triangular complexes using halide as common acceptor obeys the order of iodide〉bromide〉chloride. The halogen and hydrogen bonds work weak-cooperatively. Charge transfer bands of halogen bonding complexes between CBra and halide are observed in UV-Vis absorption spectroscopy in three solvents, and then the stoichiometry of 1：1, formation constants K and molar extinction coefficients ε of the halogen bonding complexes are obtained by Benesi-Hildebrand method. The K and ε show a dependence on the solvent dielectric constant and, on the whole, obey an order of iodide〉bromide〉chloride in the same solvents. Furthermore, the C-H vibrational frequencies of solvent molecules vary obviously with the addition of halide, which indicates the C-H…X- interaction. The experimental data indicate that the halogen bond and hydrogen bond coexist by sharing a common halide acceptor as predicted by calculation.展开更多
Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^＊ to gain a deeper insight into the nature of the N--Br haloge...Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^＊ to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 （ sp^3 ） 〉 0 （ sp^2 ）, which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.展开更多
基金This work is supported by the National Natural Science Foundation of China （No.20675009 and No.90922023） and the Research Fund for the Doctoral Program of Higher Education of China （No.273914）.
文摘The halogen and hydrogen bonding complexes and trihalomethanes （CHX3, X=C1, Br, I） are between 2,2,6,6-tetramethylpiperidine-noxyl simulated by computational quantum chem- istry. The molecular electrostatic potentials, geometrical parameters and interaction energy of halogen and hydrogen bonding complexes combined with natural bond orbital analysis are obtained. The results indicate that both halogen and hydrogen bonding interactions obey the order CI〈Br〈I, and hydrogen bonding is stronger than the corresponding halogen bond- ing. So, hydrogen bonding complexes should be dominant in trihalomethanes. However, it is possible that halogen bonding complex is competitive, even preponderant, in triiodomethane due to the similar interaction energy. This work might provide useful information on specific solvent effects as well as for understanding the mechanism of nitroxide radicals as a bioprobe to interact with the halogenated compounds in biological and biochemical fields.
基金This work is supported by the National Natural Science Foundation of China （No.20673105）.
文摘Does the halogen bonding interaction co-exist in liquid when it competes with the hydrogen bonding interaction？ The classical molecular dynamics simulations for the solvation properties of CLF molecule in water are performed with the Lennard-Jones plus Coulomb electrostatic potential parameters that are optimized with ab initio interaction energy calculations for the pre-reactive H2O-CLF complex. We find that the halogen bonding interactions occur between O and CL atoms and have the comparable strength and population with respect to the hydrogen bonding interactions of C1...H.
基金supported financially by the National Natural Science Foundation of China(Nos.21502218 and 21522209)the "Strategic Priority Research Program"(No. XDB12010100)
文摘Controlling microstructure and thin film morphology of organic semiconductors by supramolecular arrangement is critical to improving their device performance. To realize well-controlling supramolecular assembly, a core-expanded naphthalene diimides derivative （1） was designed and synthesized as an n-type organic semiconductor and also as a halogen bonding （XB） donor that could form complementary XBs with 2,2-dipyridine or 2,2-bipyrimidine acceptor. The XB interactions in the solid state of 1/2,2- dipyridine and 1/2,2-bipyrimidine were confirmed by a series of characterization methods, such as thermal gravimetric analysis （TGA）, X-ray photoelectron spectroscopy （XPS）, nuclear magnetic resonance （NMR） involving 13F NMR and solid-state 13C NMR. Organic field-effect transistors （OFETs） based on XB complexes 1/2,2-dipyridine or 1/2,2-bipyrimidine showed better device performance than that of devices based on pure 1, with the average electron mobility increased more than doubled （from 0.027cm2V-1 s-1 to 0.070cm2V-1 s-1）.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0590000)the National Natural Science Foundation of China(No.22122104)+1 种基金the CAS Project for Young Scientists in Basic Research(Grant Nos.YSBR-095 and YSBR-052)The University of East Anglia.
文摘Whether the fluorine atom(F)can engage in a halogen bond(XB)has remained a subject of ongoing debate.The discovery of N-fluoropyridinium triflate as a unique"F-cation organocatalyst"for aziridine synthesis has generally been considered the first instance of F-halogen bonding catalysis.Nevertheless,the mechanistic details of this reaction have remained elusive,and compelling evidence supporting the F-halogen bond catalysis has been lacking.In this study,we present an in-depth computational investigation of the mechanism of this reaction to gain insights into the intriguing role of the F-cation organocatalyst.Our results,however,are inconsistent with the previous prevalent F-halogen bonding catalysis mechanism but instead,bring to light a new fluorine cation transfer mechanism.This novel mechanism is supported by control experiments and can explain the observed cis-trans selectivity.
基金supported by the National Natural Science Foundation of China(Nos.22371218,82271518,21801194)Xianyang Bureau of Science and Technology(No.L2024-QCY-ZYYJJQ-260)+2 种基金The Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University(No.JCRCFZ-2022-030)Guiding Projects of Traditional Chinese Medicine in 2023~2024 by Hubei Provincial Administration of Traditional Chinese Medicine(No.ZY2023F038)the support of the Core Facility of Wuhan University and the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University。
文摘Effective treatment of subcutaneous tumors remains a focal point in cancer therapy.Photothermal therapy,a novel therapeutic approach,has emerged as a promising alternative,offering a less invasive option for the treatment of subcutaneous tumors.This study reports the exploration of novel supramolecular halogen-bonded organic frameworks(XOFs)based on[N…Br^(+)…N]halogen bonds through the ligand exchange strategy and their application in photothermal therapy.Through ligand exchange,XOF(Br)-TPy was successfully prepared,and its structure and properties were thoroughly characterized using NMR,XPS,FT-IR,and XRD techniques.Due to their cationic characteristics,these XOFs serve as effective carriers for the photothermal agent IR820.In vitro experiments demonstrated that the IR820@XOF(Br)-TPy composite exhibits excellent photothermal conversion efficiency under NIR irradiation,effectively inducing tumor cell ablation.Furthermore,in vivo studies confirmed the remarkable antitumor efficacy of the composite material in a subcutaneous tumor model.This work demonstrates that the ligand exchange strategy is a versatile and facile approach for constructing XOFs(Br)and provides a novel strategy for developing advanced photothermal therapeutic agents with significant application potential.
基金Project supported by the National Natural Science Foundation of China （No. 20502022） and the Ph.D. Fund of Ningbo （No. 2004A610010）.
文摘A series of complexes formed between halogen-containing molecules and ammonia have been investigated by means of the atoms in molecules （AIM） approach to gain a deeper insight into halogen bonding. The existence of the halogen bond critical points （XBCP） and the values of the electron density （Pb） and Laplacian of electron density （V2pb） at the XBCP reveal the closed-shell interactions in these complexes. Integrated atomic properties such as charge, energy, polarization moment, volume of the halogen bond donor atoms, and the corresponding changes （△） upon complexation have been calculated. The present calculations have demonstrated that the halogen bond represents different AIM properties as compared to the well-documented hydrogen bond. Both the electron density and the Laplacian of electron density at the XBCP have been shown to correlate well with the interaction energy, which indicates that the topological parameters at the XBCP can be treated as a good measure of the halogen bond strength In addition, an excellent linear relationship between the interatomic distance d（X…N） and the logarithm of Pb has been established.
基金Project supported by the National Natural Science Foundation of China （Nos. 20973053, 20801017）, the Natural Science Foundation of Hebei Province （Nos. B 2011205058, B2010000371）, the Education Department Foundation of Hebei Province （Nos. 2009137, ZD2010126 ）.
文摘The nature of halogen bonding in five complexes formed between the thiocyanate （NCS） radical and a BrC1 molecule was analyzed by quantum theory of atoms in molecules （QTAIM） and electron-localization function （ELF） in this paper. The calculated results show that the geometry of the halogen atom bonded at the N-atom is stable than those bonded at S- or C-atom. The molecular electrostatic potentials determine the geometries and stabilities of the complexes. The valence basin of the S- or N-atom in the electron-donating NCS radical is compressed and its population decreases during the process of formation of the halogen-bonded complexes.
基金supported by the National Basic Research Program of China (2009CB219902)the Natural Science Foundation of Shanghai (11ZR1408700)the National Natural Science Foundation of China (21136004 and 21103047)
文摘Halogen bonding interactions between several halogenated ion pairs and CO2 molecules have been investigated by means of density functional theory calculations. To account for the influence of solvent environment, the implicit polarized continuum model was also employed. The bromide and iodide cations of ionic liquids (ILs) under study can interact with CO2 molecules via X O interactions, which become much stronger in strength than those in the complexes of iodo-perfluorobenzenes, very effective halogen bond donors, with CO2 molecules. Such interactions, albeit somewhat weaker in strength, are also observed between halogenated ion pairs and CO2 molecules. Thus, the solubility of CO2 may be improved when using halogenated ILs, as a result of the formation of X O halogen bonds. Under solvent effects, the strength of the interactions tends to be weakened to some degree, with a concomitant elongation of intermolecular distances. The results presented here would be very useful in the design and synthesis of novel and potent ILs for CO2 physical absorption.
基金the National Natural Science Foundation of China (Nos. 20372077 and 90206005).
文摘Trans-5,10-bis(1-bromodifluoroacetyl-1-ethoxycarbonyl-methylidene)thianthrene (1b) was prepared from the reaction of BrCF2COC(N2)CO2Et with thianthrene. X-ray single crystal diffraction analysis showed that the inter-molecular halogen bonding and hydrogen bonding coexisted in this compound. The bromine atom acted as an elec-tron acceptor in the halogen bond and an electron donor in the hydrogen bond. It is the first example that the bro-mine atom acted as such a dual role in the hydrogen and halogen bond.
基金supported by the State Key Lab of Urban Water Resource and Environment of the Harbin Institute of Technology(No.ES202303)。
文摘Ubiquitous competition of stereospecific E2 elimination versus SN2 substitution is of central importance in chemical synthesis.Herein,we uncover how the nature of the leaving group affects the intrinsic competing dynamics that remains largely unknown as opposed to its role in reactivity.Results are presented for a prototype case of fluoride anion reacting with ethyl chloride,compared to reacting with ethyl iodide.Chemical dynamics simulations reproduce scattering signatures observed in experiments and reveal that the direct stripping/rebound mechanisms characterize the E2/S_(N)2 reactions,in line with their dynamic fingerprints identified.Quite similar structures and energetics are found for the Cl^(−)and I^(−)leaving halides,whereas the competing dynamics show markedly distinct features.A halogen-bonding attraction is found to be crucial that modifies the interaction potential in the entrance channel and essentially tunes the underlying atomistic behaviors causing a mechanistic shift.This work highlights the dynamical effects induced by a leaving group on the proceedings of baseinduced elimination and nucleophilic substitution,providing a unique insight into the reaction selectivity for complex chemical networks and environments.
基金supported by the National Natural Science Foundation of China(Nos.22371218,21702153,52270070,and 21801194)the Wuhan Science and Technology Bureau(No.whkxjsj009)+1 种基金support of the Core Facility of Wuhan Universitythe Large-scale Instrument and Equipment Sharing Foundation of Wuhan University。
文摘Efficient conversion and synergistic solar energy utilization are critical for advancing low-carbon and sustainable development.In this study,two Pt(Ⅱ)-based metal/halogen-bonded organic frameworks(MXOFBen and MXOF-Anth)were designed to enhance photoconversion efficiency and enable multifunctional integration.The ligand L-terpyr is formed by coupling tripyridine with diphenylamine dipyridine,in which the tripyridine effectively acts as a metal-ligand to lower the band gap and promote nonradiative leaps,thereby enhancing the photoconversion ability.Meanwhile,diphenylamine dipyridine serves as a[N…I^(+)…N]halogen-bonding acceptor,imparting superhydrophilicity to the materials and increasing carrier density,further improving photocatalytic performance.Experimental results demonstrate that these two MXOFs achieve impressive interfacial water evaporation efficiencies of up to87.8%and 94.0%,respectively.Additionally,the materials exhibit excellent performance in photothermal power generation and photocatalysis of H_(2)O_(2).Notably,the MXOFs also deliver strong overall performance in integrated systems combining interfacial water evaporation with photothermal power generation or photocatalysis,underscoring their exceptional photoconversion efficiency and multifunctional potential.This work introduces a novel strategy by incorporating metal-ligand and halogen bonds,offering a pathway to enhance photoconversion efficiency and develop versatile materials for advanced solar energy applications,thereby fostering the progress of high-efficiency solar energy conversion and multifunctional organic materials.
基金This work was supported by the National Natural Science Foundation of China （No.51063006 and No.50975273） and the ＂QingLan＂ Talent Engineering Funds of Tianshui Normal University.
文摘Inverse halogen bonds interactions involving Br in the electronic deficiency systems of CH3＋...Br-Y （Y=H, CCH, CN, NC） have been investigated by B3LYP/6- 311＋＋G（d, p） and MP2/6-311＋＋G（d, p） methods. The calculated interaction energies with basis set super-position error correction of the four IXBs complexes are 218.87, 219.48, 159.18, and 143.05kJ/mol （MP2/6-311＋＋G（d, p））, respectively. The relative stabilities of the four complexes increased in the order： CH3＋ … BrCN〈CH3＋…- BrNC〈CH3＋… BrH≈CH3＋ …BrCCH. Natural bond orbital theory analysis and the chemical shifts calculation of the related atoms revealed that the charges flow from Br-Y to CH3e. Here, the Br of Br-Y acts as both a halogen bond donor and an electron donor. Therefore, compared with conventional halogen bonds, the IXBs complexes formed between Br-Y and CH3＋. Atoms-in-molecules theory has been used to investigate the topological properties of the critical points of the four IXBs structures which have more covalent content.
基金supported by the Russian Science Foundation projects 22-13-00078(experimental part and XRD analysis)22-73-00021(theoretical calculations under periodic conditions and for cluster mode)The QTAIM/NCIPlot calculations were funded by the MICIU/AEI of Spain(project PID2020-115637GB-I00 FEDER funds)。
文摘Crystallization of[CuI(CNXyl)_(3)](1)with I_(2)(exhibiting strong halogen bond donor properties),at different molar ratios between the reactants,resulted in a series of(XylNC)Cu^(Ⅰ) crystal polyiodides formed along with gradual accumulation of iodine,namely[Cu(I_(3))(CNXyl)_(3)](two crystalline polymorphs 2^(Ⅰ) and 2^(Ⅱ)),[Cu(I_(3))(CNXyl)_(3)]·1/2I_(2)(2·1/2 I_(2))and[Cu(CNXyl)_(3)](I_(5))(3);all these compounds were studied by X-ray diffractometry.Molecular electrostatic potential(MEP)surface plots were also calculated using density functional theory(DFT)for isolated molecules of 2 and I_(2),showing electrophilic and nucleophilic sites.Halogen bonding in 2·1/2 I_(2) was additionally elucidated for both crystal and cluster models,including combined quantum theory of atoms-in-molecules(QTAIM)and one-electron potential(OEP)projections.For model clusters,DFT energetic analysis,quantum theory of atoms-in-molecules,combined with the noncovalent interaction index plot(QTAIM/NCIplot),natural bond orbital(NBO)donor–acceptor charge transfer analysis,and Wiberg bond index(WBI)analysis were used.In the structure of 2·1/2I_(2),the presence of an I_(2)…I_(3)_(−)halogen bonded linkage gives a key toward the understanding of the precise mechanism for the generation of I_(5)^(−)(and then I_(8)^(2−))ligands from I_(2) and metal-coordinated I_(3)_(−).
基金funded by the Russian Science Foundation(project 19-13-00013)Measurements were performed at the Center for Magnetic Resonance,Center for X-ray Diffraction Studies,Center for Chemical Analysis and Materials Research,and Chemistry Educational Center(all belonging to Saint Petersburg State University).A.F.thanks the MICIU/AEI of Spain(project PID2020-115637GB-I00,FEDER funds)for financial support of these theoretical studies.
文摘In the structures of the isostructural cocrystals[Cu^(I)_(3)(CNXyl)_(3)]·CHX_(3)(X=Br,I),two adjacent Cu^(I)-bound isocyanide groups,whose carbon lone pairs are blocked by ligation,exhibit nucleophilic properties induced by aπ-donating d10[Cu^(I)]center and function as an integrated two-center halogen bond acceptor forming bifurcatedμ_(2)-X⋯(C,C)halogen bonds.
基金financial support from the Natural Science Foundation of Shandong Province(ZR2020MB014)the Fund of State Key Laboratory of Structural Chemistry and Jinan Research Leader’s Studio(2019GXRC053)。
文摘Copper has become a favored Pb-free candidate in the exploration of metal halide photoelectric materials;however,the known hybrid copper halides(HCHs)suffer from wide band gaps,low absorption coefficients or large exciton binding energies(E_(b)),hindering their application as photodetectors.Combining functional aryl thioether with copper halide in one crystal lattice is greatly desired.However,it is impeded by the intricate and environment-unfriendly multi-step organic synthesis of aryl thioether,which involves harsh reaction conditions,toxic organic reagents and noble metal catalysts.Herein,we report the first Cl…Cl halogen bonding(XB)assembled HCH conductive framework with aryl thioether as ligand,{bis(5-chloropyridin-2-yl)sulfane(CuI)}_(n)(BCS-CuI).It was obtained by a well-designed facile and sustainable“All-in-One”synthesis strategy,where aryl halides,noble metals and harsh reaction conditions are not involved.Property measurements and theoretical calculations disclose that the XB assembled three-dimensional framework contributes significantly to the physical properties of BCS-CuI,which exhibits a small band gap of 2.44 eV,strong optical absorption and a relatively small E_(b) value of 55.8 meV.Importantly,BCS-CuI exhibits great potential application as a hypotoxicity photodetector with a high photoresponse on/off ratio of 32.9 and carrier concentration and mobility superior to that of the wellknown methylamine lead iodide(CH_(3)NH_(3))PbI_(3).
基金supported by the National Natural Science Foundation of China(No.21971100,21771097)Project of Central Plains Science and Technology Innovation Leading Talents of Henan Province(No.204200510001)Key Scientific Research Projects of Higher Education of Henan Province(No.20A150005).
文摘The development of non-noble metal ions with potential organic phosphor ligands through strong coordination bonds can afford an effective platform for achieving persistent and tunable phosphorescence at room temperature.However,successful examples of coordination polymers(CPs)or metal-organic frameworks(MOFs)exhibiting long-lasting phosphorescence emission are still rarely explored.In this work,a new strategy has been used for the first time to achieve long-lasting phosphorescence via π-type halogen bonding in coordination polymers.By the selection of two isomers 5-BIPA and 4-BIPA with different Br atom substitution positions in isophthalic acid(IPA),two new Zn(Ⅱ)-based coordination polymers exhibiting long-lasting phosphorescence emission up to the order of magnitude of millisecond(ms)were presented,which were further revealed by theoretical calculations.Optoelectronic measurements indicated that 1 showed a high photoelectron response because the delocalized π-type halogen bonding and long range order ofπ-conjugated chains afforded large electron channels for efficient charge transport.
基金supported by the U.S.Department of Energy—Chemical Sciences,Geosciences and Biosciences Division,Office of Basic Sciences,Office of Science,Heavy Elements Program,under grant number DE-FG02-05ER15736.
文摘The syntheses and crystal structures of five new compounds containing the UO_(2)^(2+)cation,2,5-diiodobenzoic acid,and a chelating N-donor(2,2’-bipyridine(bipy)(1),1,10-phenanthroline(phen)(2 and 3),2,2’:6’,2’’-terpyridine(terpy)(4),or 4’-chloro-2,2’:6’,2’’-terpyridine(Cl-terpy)(5))are described and the spectroscopic properties(both vibrational and luminescent)and stretching and interaction force constants of complexes 2,4,and 5 are reported.Single crystal X-ray diffraction analysis of these materials shows that variation of the chelating N-donor with the same benzoic acid featuring multiple,polarizable halogens at the periphery allows for the systematic accessing of uranyl oxo atoms for non-covalent assembly,which is notable as these atoms are generally terminal.Spectroscopic characterization of complexes 2,4,and 5 indicate that oxo atom participation in halogen bonding interactions may complement the effects of the electron donating ability of the capping ligand on corresponding uranyl luminescence and vibrational spectra,each contributing to the observed bathochromic shifts.
基金Department of Energy(DOE)—Chemical Sciences,Geosciences and Biosciences Division,Office of Science,Office of Basic Energy Sciences,Heavy Elements Program,under grant number DE-FG02-05ER15736supported by the Department of Defense(DoD)through the National Defense Science and Engineering Graduate(NDSEG)Fellowship Program.
文摘Harnessing the nominally terminal oxo atoms of the linear uranyl(UO_(2)^(2+))cation represents a frontier within the field of f-element hybrid materials.Here we outline a route for systematically accessing uranyl oxo atoms via judicious pairing with Ag^(+)cations or iodobenzoates,and describe the syntheses and crystal structures of four new heterometallic compounds containing Ag^(+)cations,the UO_(2)^(2+)cation,and o-(1),m-(2),p-iodo-(3),and 2,5-diiodo-(4)carboxylate ligands.Vibrational and luminescence spectroscopic properties for all four compounds are reported,as are computational findings from quantum chemical calculations and density-based quantum theory of atoms in molecules(QTAIM)analyses.Single crystal X-ray diffraction analysis of compounds 1–4 shows that the nominally terminal uranyl oxo atoms are engaged in either covalent UO_(2)–Ag cation–cation interactions(1 and 3)or non-covalent assembly via halogen bonding interactions(2 and 4).Raman,infrared(IR),and luminescence spectra of 1–4 are redshifted with respect to the free uranyl cation indicating that both halogen–oxo and cation–cation interactions weaken the U[double bond,length as m-dash]O bond,and in the case of 3 we note a rare example of activation of the uranyl asymmetric stretch(ν_(3))in the Raman spectra,likely due to the Ag–oxo cation–cation interaction lowering the symmetry of the uranyl cation.Quantum chemical calculations and QTAIM analysis highlight a quantitative difference between halogen bonds and cation–cation interactions,with the latter shown to significantly decrease uranyl bond orders and electron density at bond critical points.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20675009 and No. 90922023）. The basis set aug-cc-pVDZ-PP for iodine atom is downloaded at the website http：//bse.pnl.gov/ bse/portal.
文摘The theoretical calculation and spectroscopic experiments indicate a kind of triangular three bonding supramolecular complexes CBr4…X^-…-H-C, which consist of carbon tetrabromide, halide, and protic solvent molecule （referring to dichloromethane, chloroform and acetonitrile）, can be formed in solution. The strength of halogen and hydrogen bonds in the triangular complexes using halide as common acceptor obeys the order of iodide〉bromide〉chloride. The halogen and hydrogen bonds work weak-cooperatively. Charge transfer bands of halogen bonding complexes between CBra and halide are observed in UV-Vis absorption spectroscopy in three solvents, and then the stoichiometry of 1：1, formation constants K and molar extinction coefficients ε of the halogen bonding complexes are obtained by Benesi-Hildebrand method. The K and ε show a dependence on the solvent dielectric constant and, on the whole, obey an order of iodide〉bromide〉chloride in the same solvents. Furthermore, the C-H vibrational frequencies of solvent molecules vary obviously with the addition of halide, which indicates the C-H…X- interaction. The experimental data indicate that the halogen bond and hydrogen bond coexist by sharing a common halide acceptor as predicted by calculation.
基金Supported by the National Natural Science Foundation of China(No20502022)the Natural Science Foundation of Zhe-jiang Province(NoY406374)
文摘Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^＊ to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 （ sp^3 ） 〉 0 （ sp^2 ）, which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.
