Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact...Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni（Ⅱ） DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co（CN）5X]2 （X = Br^- and N3^-） exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.展开更多
Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H...Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.展开更多
The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-d...The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-dimensional polymeric chain-Ni(pn)2-NC-Ni(CN)2-CN-Ni(pn)2- inwhich the Ni(II) centers are linked by two CN groups.展开更多
Reaction of [Mn（TTF-salphen）][OAc] （TTF-salphen2=2,2＇-（（2-（4,5-bis（methylthio）-1,3-dithiol-2-ylidene）-1,3-benzodithiole- 5,6-diyl）bis（nitrilomethylidyne）bis（pbenolate）dianion） and the cyanometalate bui...Reaction of [Mn（TTF-salphen）][OAc] （TTF-salphen2=2,2＇-（（2-（4,5-bis（methylthio）-1,3-dithiol-2-ylidene）-1,3-benzodithiole- 5,6-diyl）bis（nitrilomethylidyne）bis（pbenolate）dianion） and the cyanometalate building blocks [n-Bu4N][（Tp）Fe（CN）3] （Tp =Tris（pyrazolyl）hydroborate） or [n-Bu4N][Ru（salen）（CN）2] （salen2 =N,N＇-ethylenebis（salicylideneimine）dianion） resulted in the formation of two redox-active complexes, the dinuclear heterometallic complex [（Tp）Fe（CN）3Mn（TTF-salphen）＇CH3OH] （1） and the one dimensional complex [Ru（salen）（CN）2Mn（TTF-salphen）]n （2）. Both complexes were characterized by X-ray crystallography and solid state electrochemistry, in addition to static and dynamic magnetic measurements. Antiferromagnetic couplings are found to be operative between metal ion centers bridged by cyanide in both complexes. Complex 1 exhibited field-induced SMM behavior with an energy barrier of 13.8 K. The introduction of the redox-active TTF unit into cyanidebridged complexes with interesting magnetic properties renders them promising candidates for the construction of new hybrid inorganic-organic materials.展开更多
The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.6...The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.展开更多
The syntheses, crystal structures and magnetic properties of two cyano-bridged heterobimetallic compounds prepared from a paramagnetic Ru^Ⅲ building block, transK[Ru^Ⅲ（salchda）（CN）2]（1, salchda = N,N＇-bis（sal...The syntheses, crystal structures and magnetic properties of two cyano-bridged heterobimetallic compounds prepared from a paramagnetic Ru^Ⅲ building block, transK[Ru^Ⅲ（salchda）（CN）2]（1, salchda = N,N＇-bis（salicylidene）-o-cyclohexylenediamine）, are described.1 reacts with hydrated CoCl2 and [Mn Ⅲ（salchda）（Cl）（H2O）] in MeOH to produce a trinuclear compound {[Ru^Ⅲ（salchda）（CN）]2（μ-CN）2[Co（MeOH）4]·4MeOH}n（2） and a dinuclear{[Ru^Ⅲ（salchda）（CN）]（μ-CN）[Mn^Ⅲ（salchda）（MeOH）]·2MeOH}n（3）, respectively. Both compounds exhibit intramolecular ferromagnetic coupling between Ru^Ⅲ and 3-d metal centers via the cyano bridge and intermolecular antiferromagnetic coupling. Moreover, 2 exhibits antiferromagnetic ordering below 3.4 K.展开更多
The engineering of switchable molecules with magnetic multistability is lying on the cutting-edge research topics for integrating multi-switches and ternary memory devices. Here we presented a cyanide-bridged {Fe_(2)^...The engineering of switchable molecules with magnetic multistability is lying on the cutting-edge research topics for integrating multi-switches and ternary memory devices. Here we presented a cyanide-bridged {Fe_(2)^(Ⅲ)Fe^(Ⅱ)} desolvated complex {[(pzTp)Fe^(Ⅲ)-(CN)3]2[Fe^(Ⅱ)(L)]} (1), obtained through single-crystal-to-single-crystal (SCSC) transformation from its solvated phase {[(pzTp)-Fe^(Ⅲ)(CN)3]2[Fe^(Ⅱ)(L)]}·2CH_(3)OH·5H_(2)O (1·sol). Remarkably, 1 exhibited unprecedented three-step transition in magnetization with wide thermal hysteresis (44, 40, and 36 K) in the temperature range of 80–320 K. The detailed studies demonstrated that the tristable character originates from both an order-disorder structural phase transition (SPT) and a strongly cooperative two-step spin crossover (SCO) process. This work thus provides a new promising strategy for realizing multiple bistablity in magnetization by introducing two different transitions.展开更多
The engineering of switchable moleculeswith dramatic magnetic change is currently among themost active areas in chemical research.Here,two cyanide-bridged mixed-valence{Fe^(Ⅲ)_(4)Fe^(Ⅱ)_(4)}cubes were prepared,both ...The engineering of switchable moleculeswith dramatic magnetic change is currently among themost active areas in chemical research.Here,two cyanide-bridged mixed-valence{Fe^(Ⅲ)_(4)Fe^(Ⅱ)_(4)}cubes were prepared,both of which,interestingly,exhibited reversible thermally inducedmetal-to-metal charge transfer(MMCT)behavior between{Fe^(Ⅲ,LS)_(4)Fe^(Ⅱ,HS)_(4)}and{Fe^(Ⅱ,LS)_(4)Fe^(Ⅲ,HS)_(4)}configurations with the transition temperature(T_(1/2))of 274 and 230 K,respectively.These cubes provided a rare example of discrete homometallic complexes exhibiting the reversible MMCT rather than spin crossover behavior.In stark contrast to the heterometallic Fe/Co system,in which the charge transfer(CT)and spin transition(ST)processes occur simultaneously,the detailed structural and Mössbauer spectroscopy analyses confirmed the CT property without involving ST.In addition,both of these cubes showed excellent redox flexibility in solutionwith seven quasi accessible electronic states.展开更多
基金the National Natural Science Foundation of China(No.50273031)China Postdoctoral Science Foundation(No.20060400339).
文摘Various novel double metal cyanide （DMC） catalysts were successfully prepared by modifying the central metal （M） and one of cyanide ion （CN-） in Zna[M（CN）b]c complex. Such modifications have significant impact on the catalytic efficiency as well as the polymer selectivity for the reaction of PO/CO2. Zn-Ni（Ⅱ） DMC is a potential catalyst for alternating copolymerization of PO/CO2,and DMC catalysts based on Zn3[Co（CN）5X]2 （X = Br^- and N3^-） exhibit moderate efficiency for the production of polycarbonates.This research presents the preliminary exploration of novel DMC complex via chemical modification of its central metal and ligand.
文摘Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complex as the catalyst was carried out. The structure of random copolymers was confirmed by C-13-NMR and IR spectra. H-1-NMR analysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecular weight copolymers with various EO content were obtained and their values of molecular weight distribution (MWD) fell in the range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO+PO to initiator moles used, The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.
文摘The synthesis, structure and characterization of a new one-dimensional cyanide-bridgedcomplex [Ni(pn)_2Ni(CN)4]n'nH2O (where pn = 1,2-diaminopropane) are described. The structure ofthis complex consists of a one-dimensional polymeric chain-Ni(pn)2-NC-Ni(CN)2-CN-Ni(pn)2- inwhich the Ni(II) centers are linked by two CN groups.
基金supported by the National Basic Research Program of China(2011CB808704,2013CB922101)the National Natural Science Foundation of China(51173075,91022031)the Australian Research Council
文摘Reaction of [Mn（TTF-salphen）][OAc] （TTF-salphen2=2,2＇-（（2-（4,5-bis（methylthio）-1,3-dithiol-2-ylidene）-1,3-benzodithiole- 5,6-diyl）bis（nitrilomethylidyne）bis（pbenolate）dianion） and the cyanometalate building blocks [n-Bu4N][（Tp）Fe（CN）3] （Tp =Tris（pyrazolyl）hydroborate） or [n-Bu4N][Ru（salen）（CN）2] （salen2 =N,N＇-ethylenebis（salicylideneimine）dianion） resulted in the formation of two redox-active complexes, the dinuclear heterometallic complex [（Tp）Fe（CN）3Mn（TTF-salphen）＇CH3OH] （1） and the one dimensional complex [Ru（salen）（CN）2Mn（TTF-salphen）]n （2）. Both complexes were characterized by X-ray crystallography and solid state electrochemistry, in addition to static and dynamic magnetic measurements. Antiferromagnetic couplings are found to be operative between metal ion centers bridged by cyanide in both complexes. Complex 1 exhibited field-induced SMM behavior with an energy barrier of 13.8 K. The introduction of the redox-active TTF unit into cyanidebridged complexes with interesting magnetic properties renders them promising candidates for the construction of new hybrid inorganic-organic materials.
文摘The crystal structure of the title compound C 8H 16 CuN 8Ni has been determined by single crystal X ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) , α=106.67(3), β=91.33(4), γ=106.80(6)°, V=341.3(3) 3, Z=1, M r=346.54, F(000)=177, μ =2\^933mm -1 , D c =1.686 Mg/m 3. The final R factor is 0.0603 for 1214 unique observed reflections 〔 I≥2σ(I) 〕. The structure consists of 〔Cu(en) 2〕 2+ (en=ethylenediamine) cations and 〔Ni(CN) 4〕 2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hydrogen bonds of N(4)…H-N(5) exist,with distance 3.148 , at the same time the hydrogen bonds of N(4)…H-N(7a) and N(5)-H…N(1a) (a: x-1,y-1,z-1 ) between the interchains also exist, with distances of 3.160 and 3.124 , so it forms a three\|dimensional structure of the title compound.
基金supported by the financial support of National Natural Science Foundation of China(21201023)the scientific research fund of Hubei Provincial Education Department(D20131202)
文摘The syntheses, crystal structures and magnetic properties of two cyano-bridged heterobimetallic compounds prepared from a paramagnetic Ru^Ⅲ building block, transK[Ru^Ⅲ（salchda）（CN）2]（1, salchda = N,N＇-bis（salicylidene）-o-cyclohexylenediamine）, are described.1 reacts with hydrated CoCl2 and [Mn Ⅲ（salchda）（Cl）（H2O）] in MeOH to produce a trinuclear compound {[Ru^Ⅲ（salchda）（CN）]2（μ-CN）2[Co（MeOH）4]·4MeOH}n（2） and a dinuclear{[Ru^Ⅲ（salchda）（CN）]（μ-CN）[Mn^Ⅲ（salchda）（MeOH）]·2MeOH}n（3）, respectively. Both compounds exhibit intramolecular ferromagnetic coupling between Ru^Ⅲ and 3-d metal centers via the cyano bridge and intermolecular antiferromagnetic coupling. Moreover, 2 exhibits antiferromagnetic ordering below 3.4 K.
基金supported by the Stable Support Plan Program of Shenzhen Natural Science Fund (20200925151834005)the National Natural Science Foundation of China (21671095)the China Postdoctoral Science Foundation (2020M682763)。
文摘The engineering of switchable molecules with magnetic multistability is lying on the cutting-edge research topics for integrating multi-switches and ternary memory devices. Here we presented a cyanide-bridged {Fe_(2)^(Ⅲ)Fe^(Ⅱ)} desolvated complex {[(pzTp)Fe^(Ⅲ)-(CN)3]2[Fe^(Ⅱ)(L)]} (1), obtained through single-crystal-to-single-crystal (SCSC) transformation from its solvated phase {[(pzTp)-Fe^(Ⅲ)(CN)3]2[Fe^(Ⅱ)(L)]}·2CH_(3)OH·5H_(2)O (1·sol). Remarkably, 1 exhibited unprecedented three-step transition in magnetization with wide thermal hysteresis (44, 40, and 36 K) in the temperature range of 80–320 K. The detailed studies demonstrated that the tristable character originates from both an order-disorder structural phase transition (SPT) and a strongly cooperative two-step spin crossover (SCO) process. This work thus provides a new promising strategy for realizing multiple bistablity in magnetization by introducing two different transitions.
基金supported by the Stable Support Plan Program of Shenzhen Natural Science Fund(no.20200925151834005)the National Natural Science Foundation of China(nos.21671095 and 21901108).
文摘The engineering of switchable moleculeswith dramatic magnetic change is currently among themost active areas in chemical research.Here,two cyanide-bridged mixed-valence{Fe^(Ⅲ)_(4)Fe^(Ⅱ)_(4)}cubes were prepared,both of which,interestingly,exhibited reversible thermally inducedmetal-to-metal charge transfer(MMCT)behavior between{Fe^(Ⅲ,LS)_(4)Fe^(Ⅱ,HS)_(4)}and{Fe^(Ⅱ,LS)_(4)Fe^(Ⅲ,HS)_(4)}configurations with the transition temperature(T_(1/2))of 274 and 230 K,respectively.These cubes provided a rare example of discrete homometallic complexes exhibiting the reversible MMCT rather than spin crossover behavior.In stark contrast to the heterometallic Fe/Co system,in which the charge transfer(CT)and spin transition(ST)processes occur simultaneously,the detailed structural and Mössbauer spectroscopy analyses confirmed the CT property without involving ST.In addition,both of these cubes showed excellent redox flexibility in solutionwith seven quasi accessible electronic states.
