Summary of main observation and conclusion Serf-assembly of the [Mo(CN)7]^4-anion and the Mn^2+ ion in the aqueous solution containing ammonium formate results in a new coordination polymer,{(NH4)3[(H2O)Mn3(HCOO)][Mo(...Summary of main observation and conclusion Serf-assembly of the [Mo(CN)7]^4-anion and the Mn^2+ ion in the aqueous solution containing ammonium formate results in a new coordination polymer,{(NH4)3[(H2O)Mn3(HCOO)][Mo(CN)7]2·4H2O}n.Single crystal X-ray analysis revealed a very complicated three-dimensional (3D)framework,where both the [Mo(CN)7]^4- and the formate anions act as bridges between the Mn^Ⅱ centers.Magnetic measurements revealed that this compound displays ferrimagnetic ordering below 70 K.Competing antiferromagnetic interactions between the spin carriers might lead to spin frustration and non-linear alignment of the magnetic moments.Specifically,this compound is the first mixed [Mo(CN)7]^4-/HCOO^- bridged molecule magnet.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
Single-molecule magnets(SMMs)are paramagnetic molecules that can be magnetized below a certain temperature and have potential applications in high-density information storage,magnetic-qubits,spintronic devices,etc.The...Single-molecule magnets(SMMs)are paramagnetic molecules that can be magnetized below a certain temperature and have potential applications in high-density information storage,magnetic-qubits,spintronic devices,etc.The discovery of the first SMM,Mn12,opened a new era of molecular magnetism and promoted collaborative researches between chemists and physicists for their exotic quantum as well as classical magnetic properties.In the recent past,great efforts have been madefto develop strategies for constructing new SMMs with high energy barriers(Ueff)and blocking temperatures(Tb), resulting in great and fast development of SMMs.In this concise review,we highlight the main synthetic approaches and representative results in the design and synthesis of high performance.SMMs.We hope to give the readers a basic understanding of SMMs and a snapshot of the representative researches on SMMs from a perspective of synthetic chemists.展开更多
Precise modulation of the magnetic anisotropy of metal ions remains highly important for the development of high–performance single-molecule magnets(SMMs).We herein reported the synthetic,structural,spectral,magnetic...Precise modulation of the magnetic anisotropy of metal ions remains highly important for the development of high–performance single-molecule magnets(SMMs).We herein reported the synthetic,structural,spectral,magnetic,and computational studies on four mononuclear Co^(Ⅱ) complexes in a distorted octahedral environment.The change of the organosulfonate anions triggers significant modification of the distorted octahedral CoN6 coordination sphere,which enables us to tackle the influence of the structural distortion on the magnetic anisotropy in these complexes.Magnetic measurements revealed that the four complexes possess easy–plane magnetic anisotropy with large and positive zero-field splitting parameters,which decrease with the increasing distortion of the pseudo–octahedral Co^(Ⅱ) coordination geometry.This correlation was further confirmed by high–frequency/–field EPR(HF–EPR)spectra and theoretical calculations.Dynamic magnetic susceptibility measurements indicate that these complexes both exhibit slow magnetic relaxation under an external dc field,indicating the field-induced single-ion magnets(SIMs)of the four complexes.These results indicate that structural distortion plays an important role in the magnetic anisotropy of CoⅡcomplexes and should be carefully considered in the design of molecular complexes with high magnetic anisotropy.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
文摘Summary of main observation and conclusion Serf-assembly of the [Mo(CN)7]^4-anion and the Mn^2+ ion in the aqueous solution containing ammonium formate results in a new coordination polymer,{(NH4)3[(H2O)Mn3(HCOO)][Mo(CN)7]2·4H2O}n.Single crystal X-ray analysis revealed a very complicated three-dimensional (3D)framework,where both the [Mo(CN)7]^4- and the formate anions act as bridges between the Mn^Ⅱ centers.Magnetic measurements revealed that this compound displays ferrimagnetic ordering below 70 K.Competing antiferromagnetic interactions between the spin carriers might lead to spin frustration and non-linear alignment of the magnetic moments.Specifically,this compound is the first mixed [Mo(CN)7]^4-/HCOO^- bridged molecule magnet.
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We acknowledge the financial support of the National Key R&D Program of China(No.2018YFA0306002)NSFC(Nos.21973039,21522103)the China Postdoctoral Science Foundation(No.2018M640473).
文摘Single-molecule magnets(SMMs)are paramagnetic molecules that can be magnetized below a certain temperature and have potential applications in high-density information storage,magnetic-qubits,spintronic devices,etc.The discovery of the first SMM,Mn12,opened a new era of molecular magnetism and promoted collaborative researches between chemists and physicists for their exotic quantum as well as classical magnetic properties.In the recent past,great efforts have been madefto develop strategies for constructing new SMMs with high energy barriers(Ueff)and blocking temperatures(Tb), resulting in great and fast development of SMMs.In this concise review,we highlight the main synthetic approaches and representative results in the design and synthesis of high performance.SMMs.We hope to give the readers a basic understanding of SMMs and a snapshot of the representative researches on SMMs from a perspective of synthetic chemists.
基金supported by the National Key R&D Program of China(No.2018YFA0306002)the National Natural Science Foundation of China(Nos.21973039,21973046)+1 种基金D.S.thanks the Huanggang Normal University for a start-up fund(No.2042021033)the Open Foundation of State Key Laboratory of Coordination Chemistry(No.SKLCC2208).
文摘Precise modulation of the magnetic anisotropy of metal ions remains highly important for the development of high–performance single-molecule magnets(SMMs).We herein reported the synthetic,structural,spectral,magnetic,and computational studies on four mononuclear Co^(Ⅱ) complexes in a distorted octahedral environment.The change of the organosulfonate anions triggers significant modification of the distorted octahedral CoN6 coordination sphere,which enables us to tackle the influence of the structural distortion on the magnetic anisotropy in these complexes.Magnetic measurements revealed that the four complexes possess easy–plane magnetic anisotropy with large and positive zero-field splitting parameters,which decrease with the increasing distortion of the pseudo–octahedral Co^(Ⅱ) coordination geometry.This correlation was further confirmed by high–frequency/–field EPR(HF–EPR)spectra and theoretical calculations.Dynamic magnetic susceptibility measurements indicate that these complexes both exhibit slow magnetic relaxation under an external dc field,indicating the field-induced single-ion magnets(SIMs)of the four complexes.These results indicate that structural distortion plays an important role in the magnetic anisotropy of CoⅡcomplexes and should be carefully considered in the design of molecular complexes with high magnetic anisotropy.
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.
