Intermolecular interactions between PH2Cl and Ar–R（R = H,OH,NH2,CH3,Br,Cl,F,CN,NO2） were calculated by using MP2/aug-cc-p VDZ quantum chemical method.It has been shown from our calculations that the aromatic rings ...Intermolecular interactions between PH2Cl and Ar–R（R = H,OH,NH2,CH3,Br,Cl,F,CN,NO2） were calculated by using MP2/aug-cc-p VDZ quantum chemical method.It has been shown from our calculations that the aromatic rings with electron-withdrawing groups represent much weaker binding affinities than those with electron-donating groups.The charge-transfer interaction between PH2Cl and Ar–R plays an important role in the formation of pnicogen bond complexes,as revealed by NBO analysis.Nevertheless,AIM analysis shows that the nature of the interactions between PH2Cl and Ar–R is electrostatic,and the interaction energies of the complexes are correlated positively with the electron densities in the bond critical points（BCPs）.RDG/ELF graphical analyses were performed to visualize the positions and strengths of the pnicogen bonding,as well as the spatial change of the electron localization upon the formation of complexes.The π-type halogen bond was also calculated,and it has been revealed that the π-type pnicogen bond systems are more stable than the halogen bond ones.展开更多
The reaction of pyrrole with 4-hydroxybenzaldehyde and 4-pyridinecarboxaldehyde afforded new porphyrin ligand 1. Treatment of 1 with copper( II ) acetate, cobalt ( II ) acetate gave complexes 2-3 respectively. 2 and 3...The reaction of pyrrole with 4-hydroxybenzaldehyde and 4-pyridinecarboxaldehyde afforded new porphyrin ligand 1. Treatment of 1 with copper( II ) acetate, cobalt ( II ) acetate gave complexes 2-3 respectively. 2 and 3 reacted with Merrifield's peptide resin produced 4 and 5. Complexes 4 and 5 reacted with methyl iodide respectively gave 6-7. The new compounds 1-7 have been identified by H-1 NMR, IR, MS and UV-visible spectra, elemental analysis and AES.展开更多
Aliphatic homo-polypeptoids of NAla, NVal, NIle and NLeu both in the presence and absence of protecting groups adopt helical structures without hydrogen bonds with Φ, Ψ values of ~ 0, ± 90° with trans amid...Aliphatic homo-polypeptoids of NAla, NVal, NIle and NLeu both in the presence and absence of protecting groups adopt helical structures without hydrogen bonds with Φ, Ψ values of ~ 0, ± 90° with trans amide bonds. These structures are stabilized by carbonyl-carbonyl interactions and characterized by ~ 3.16 residues per turn with a pitch of ~ 6.13 ?. It has been shown that like polyvaline and polyleucine peptides, poly-peptoids can also be exploited for the construction of potential surfactant like molecules by incorporating charged amino acid residues at the N terminal. A single-handed template with Φ, Ψ values of ~ 0, 90° can be attained by incorporating L-leu or L-val at the C-terminal of poly-NIle. Analysis of the simulation results in water as a function of time reveals that the opening of helical structures without hydrogen bonds takes place at sub-picosecond time scale starting from the N-terminal. This leads to the formation of collagen or inverse-collagen type structures (Φ, Ψ ~ -60, 145° and 60, -145° respectively) stabilized by interactions of water molecules with the backbone carbonyl groups.展开更多
Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond...Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond programs, with the United States coal system having been in place since 1977. China implemented a bonding system in 1998 and by 2013 all 31 provinces had established a system. An effective bonding system must be conditioned on fair and enforceable nationwide reclamation standard, stimulate companies to conduct reclamation by forming economic incentives rather than penalties that become a liability, and allow for full public participation. Based on these principles, this paper compares seven important factors for a successful reclamation bonding system： laws and regulations, administrative authority, bond types, bond size, calculation method, bond release, and public participation. The results show variation in policies and procedures for bonding among countries. Using principles and policies primarily from the United States, China should establish a national reclamation bonding system with legislation that forms a national authority to oversee and enforce reclamation standards and bond requirements. In addition, China can expand bond financial types and strategies, set the size of reclamation bonds at the level of a third-party reclamation cost, and set unified standards for calculation. Phased bond release should be established with specific reclamation criteria for each phase of release. Finally, bonding regulations should clearly identify opportunities for full public participation in the process.展开更多
In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-...In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-pir orbitals that the ligand Mo3S44+ bonds to the M atom to form these class clusters. It is revealed that the charges transfer from the M atom to Mo atom of the ligand Mo3S44+ and its relationship with the MC (multiple center) d-pπ orbitals. Based on the charge transfer the electronic spectrum and the magnetic property of some cubane clusters have been discussed.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 crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, h...The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.展开更多
基金Supported by the Science and Technology Project of Zhejiang Province(2016C33039)Natural Science Foundation of Zhejiang Province(LY14C030004)+2 种基金National Natural Science Foundation of China(21272211)Project of the Special Foundation for Provincial Research Institutes of Zhejiang Province,China(2017F50002)Science and Technology Planning Project of the Zhejiang Provincial Department of Water Resources(RB1608)
文摘Intermolecular interactions between PH2Cl and Ar–R（R = H,OH,NH2,CH3,Br,Cl,F,CN,NO2） were calculated by using MP2/aug-cc-p VDZ quantum chemical method.It has been shown from our calculations that the aromatic rings with electron-withdrawing groups represent much weaker binding affinities than those with electron-donating groups.The charge-transfer interaction between PH2Cl and Ar–R plays an important role in the formation of pnicogen bond complexes,as revealed by NBO analysis.Nevertheless,AIM analysis shows that the nature of the interactions between PH2Cl and Ar–R is electrostatic,and the interaction energies of the complexes are correlated positively with the electron densities in the bond critical points（BCPs）.RDG/ELF graphical analyses were performed to visualize the positions and strengths of the pnicogen bonding,as well as the spatial change of the electron localization upon the formation of complexes.The π-type halogen bond was also calculated,and it has been revealed that the π-type pnicogen bond systems are more stable than the halogen bond ones.
文摘The reaction of pyrrole with 4-hydroxybenzaldehyde and 4-pyridinecarboxaldehyde afforded new porphyrin ligand 1. Treatment of 1 with copper( II ) acetate, cobalt ( II ) acetate gave complexes 2-3 respectively. 2 and 3 reacted with Merrifield's peptide resin produced 4 and 5. Complexes 4 and 5 reacted with methyl iodide respectively gave 6-7. The new compounds 1-7 have been identified by H-1 NMR, IR, MS and UV-visible spectra, elemental analysis and AES.
文摘Aliphatic homo-polypeptoids of NAla, NVal, NIle and NLeu both in the presence and absence of protecting groups adopt helical structures without hydrogen bonds with Φ, Ψ values of ~ 0, ± 90° with trans amide bonds. These structures are stabilized by carbonyl-carbonyl interactions and characterized by ~ 3.16 residues per turn with a pitch of ~ 6.13 ?. It has been shown that like polyvaline and polyleucine peptides, poly-peptoids can also be exploited for the construction of potential surfactant like molecules by incorporating charged amino acid residues at the N terminal. A single-handed template with Φ, Ψ values of ~ 0, 90° can be attained by incorporating L-leu or L-val at the C-terminal of poly-NIle. Analysis of the simulation results in water as a function of time reveals that the opening of helical structures without hydrogen bonds takes place at sub-picosecond time scale starting from the N-terminal. This leads to the formation of collagen or inverse-collagen type structures (Φ, Ψ ~ -60, 145° and 60, -145° respectively) stabilized by interactions of water molecules with the backbone carbonyl groups.
文摘Mine reclamation bonds are used in countries with mineral mining to ensure that reclamation of the mined area is completed. The United States, Canada, and Australia are countries with established mine reclamation bond programs, with the United States coal system having been in place since 1977. China implemented a bonding system in 1998 and by 2013 all 31 provinces had established a system. An effective bonding system must be conditioned on fair and enforceable nationwide reclamation standard, stimulate companies to conduct reclamation by forming economic incentives rather than penalties that become a liability, and allow for full public participation. Based on these principles, this paper compares seven important factors for a successful reclamation bonding system： laws and regulations, administrative authority, bond types, bond size, calculation method, bond release, and public participation. The results show variation in policies and procedures for bonding among countries. Using principles and policies primarily from the United States, China should establish a national reclamation bonding system with legislation that forms a national authority to oversee and enforce reclamation standards and bond requirements. In addition, China can expand bond financial types and strategies, set the size of reclamation bonds at the level of a third-party reclamation cost, and set unified standards for calculation. Phased bond release should be established with specific reclamation criteria for each phase of release. Finally, bonding regulations should clearly identify opportunities for full public participation in the process.
文摘In this work, with the analysis on MO and electronic structure for a series of heteronuclear cluster with cubane type (Mo4S1 )xMn1(x=1.2. M = Cu, W, Ni, Sb, Mo, Sn, Cu2) we found that it is with the multiple center d-pir orbitals that the ligand Mo3S44+ bonds to the M atom to form these class clusters. It is revealed that the charges transfer from the M atom to Mo atom of the ligand Mo3S44+ and its relationship with the MC (multiple center) d-pπ orbitals. Based on the charge transfer the electronic spectrum and the magnetic property of some cubane clusters have been discussed.
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This work was supported by the State Key Laboratory of Structural Chemistry (030065) the Chinese Academy of Sciences the NNSFC (20073048) and the NSF of Fujian province (2002F015)
文摘The crystal structure of the title compound, [enH2][Fe{MoⅤ6O12(OH)3(HPO4)- (H2PO4)3}2]6en6H2O (en = H2NCH2CH2NH2), hydrothermally synthesized from a mixture of Na2MoO42H2O, Fe2(SO4)3, H3PO4, H2N(CH2)2NH2 and water, has been determined by single- crystal X-ray diffraction. The crystal is of triclinic, space group P?with a = 11.9014(1), b = 13.4246(2), c = 13.8719(2) , a = 87.465(1), b = 69.981(1), g = 64.960(1)? V = 1873.46(4) 3, Z = 1, Mr = 2997.89, F(000) = 1466, m = 2.427 mm-1 and Dc = 2.657 g/cm3. The final R = 0.0404 for 5570 observed reflections (I > 2s(I)). The structural analysis reveals that each cluster anion contains two coplanar {Mo6} rings of six edge-sharing Mo(O5OH) octahedra, and the two {Mo6} rings are linked together through one octahedral FeⅡ ion to generate a sandwich-type cluster with rigorous () symmetry. Moreover, these clusters are further linked into a three-dimensional frame- work by hydrogen bonds.
