Two iodoargentate hybrids templated by viologen or viologen-like cations, i.e. [MV（Ag2I4）]n （1） and [MBYP（AgI2）]n （2）, （MV^2＋ = methyl viologen, MBYP^＋ = 1-methyl-2,2＇- bipyridine） have been synthesized i...Two iodoargentate hybrids templated by viologen or viologen-like cations, i.e. [MV（Ag2I4）]n （1） and [MBYP（AgI2）]n （2）, （MV^2＋ = methyl viologen, MBYP^＋ = 1-methyl-2,2＇- bipyridine） have been synthesized in polar organic solvents. （Ag2I4）n^2- and （AgI2）n^2- chains in both compounds were constructed from edge-sharing of normal and distorted AgI4 tetrahedra, and a 2-D supramolecular layer based on C–H…I hydrogen bond was observed in 1. The band gaps of 1.54 and 2.67 eV indicated their semiconductor nature. Their band gap difference was led by different hydrogen bond donors in MV^2＋ and MBYP^＋, which result in more diffused p-π＊ antibonding orbitals in MV^2＋.展开更多
Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound w...Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.展开更多
Hybrid density functional calculations was used to comprehensively study the electronic structure of S-,Snand Pb-monodoped and（Sn,S）-and（Pb,S）-codoped hexagonal WO_3（h-WO_3）in order to improve their visible ligh...Hybrid density functional calculations was used to comprehensively study the electronic structure of S-,Snand Pb-monodoped and（Sn,S）-and（Pb,S）-codoped hexagonal WO_3（h-WO_3）in order to improve their visible light photocatalytic activity.Results indicate that the（Sn,S）-and（Pb,S）-codoped h-WO_3 can realize a significant band gap reduction and prevent the formation of empty states in the valence band of h-WO_3,while Sn/Pb-monodoped h-WO_3 cannot,because in（Sn,S）-and（Pb,S）-codoping,the S-doping introduces the fully occupied S 3p states in the forbidden band gap of h-WO_3 and the acceptor metals（Sn and Pb）would assist the coupling of the introduced S with its nearest O.In particular,the（Sn,S）-codoped h-WO_3 has the narrowest band gap of 1.85 eV and highest reducing ability among the doped case.Moreover,the calculated optical absorption spectra show that（Sn,S）-codoping can improve the visible light absorption.In short,these results indicate that the（Sn,S）-codoped h-WO_3 is a promising material in solar-driven water splitting.展开更多
基金Project supported by the National Natural Science Foundation for Fostering Talents in Basic Research(No.J1103303)National Natural Science Foundation of China(21271043)Qishan Scholars Program of Fuzhou University(No.XQS-1403)
文摘Two iodoargentate hybrids templated by viologen or viologen-like cations, i.e. [MV（Ag2I4）]n （1） and [MBYP（AgI2）]n （2）, （MV^2＋ = methyl viologen, MBYP^＋ = 1-methyl-2,2＇- bipyridine） have been synthesized in polar organic solvents. （Ag2I4）n^2- and （AgI2）n^2- chains in both compounds were constructed from edge-sharing of normal and distorted AgI4 tetrahedra, and a 2-D supramolecular layer based on C–H…I hydrogen bond was observed in 1. The band gaps of 1.54 and 2.67 eV indicated their semiconductor nature. Their band gap difference was led by different hydrogen bond donors in MV^2＋ and MBYP^＋, which result in more diffused p-π＊ antibonding orbitals in MV^2＋.
文摘Reaction products of 2,4,6-tris(4-phenyl-phenoxy)-1,3,5-triazine derived from 4-phenylphenol cyanate ester and phenyl glycidyl ether were analyzed. In addition to an isocyanurate compound and an oxazolidone compound which were well known as reaction products of cyanate esters and epoxy resins, compounds with hybrid ring structure of cyanurate/isocyanurate were determined. Gibbs free energies of the compound having hybrid ring structure of cyanurate/isocyanurate with two isocyanurate moiety were found to be lower than that of the compound with cyanurate ring structure through calculations. Calculation data supported the existence of hybrid ring structure of cy-anurate/isocyanurate. It was revealed that isomerization from cyanurate to isocyanurate occurs via hybrid ring structure of cyanurate/isocyanurate in the reaction of aryl cyanurate and epoxy.
基金supported by the National Natural Science Foundation of China (21476024, 21576008, 91334203 and 91634116)the National Key Technology Support Program (2014BAE12B01)+2 种基金Beijing Municipal Science and Technology Project (Z151100003315005)the Fundamental Research Funds for the Central Universities (PYCC1705)the “Chemical Grid Project” of BUCT
文摘Hybrid density functional calculations was used to comprehensively study the electronic structure of S-,Snand Pb-monodoped and（Sn,S）-and（Pb,S）-codoped hexagonal WO_3（h-WO_3）in order to improve their visible light photocatalytic activity.Results indicate that the（Sn,S）-and（Pb,S）-codoped h-WO_3 can realize a significant band gap reduction and prevent the formation of empty states in the valence band of h-WO_3,while Sn/Pb-monodoped h-WO_3 cannot,because in（Sn,S）-and（Pb,S）-codoping,the S-doping introduces the fully occupied S 3p states in the forbidden band gap of h-WO_3 and the acceptor metals（Sn and Pb）would assist the coupling of the introduced S with its nearest O.In particular,the（Sn,S）-codoped h-WO_3 has the narrowest band gap of 1.85 eV and highest reducing ability among the doped case.Moreover,the calculated optical absorption spectra show that（Sn,S）-codoping can improve the visible light absorption.In short,these results indicate that the（Sn,S）-codoped h-WO_3 is a promising material in solar-driven water splitting.
