Spin-crossover(SCO)complexes have been extensively studied in the past few decades owing to their bistable nature which find application in a myriad of areas.In order to enhance and optimize the SCO behavior,considera...Spin-crossover(SCO)complexes have been extensively studied in the past few decades owing to their bistable nature which find application in a myriad of areas.In order to enhance and optimize the SCO behavior,considerable attention is being paid towards the synthesis of discrete multinuclear spin-crossover complex systems.Here,two mixed-valence Fe_(2)^(Ⅲ)Fe^(Ⅱ)trinuclear complexes of the formula{[Fe^(Ⅱ)(TPMA)][Fe^(Ⅲ)(TpR)(CN)_(3)]_(2)}·MeOH·2H_(2)O(1)and{[Fe^(Ⅱ)(TPMA)][Fe^(Ⅲ)(TpR)(CN)_(3)]_(2)}·H_(2)O(2)[where TPMA=tris(2-pyridylmethyl)amine,Tp=tris(pyrazol-1-yl)borate,R=3,5-dimethyl for 1 and H for 2]were synthesized and characterized.Magnetic measurements confirmed that complex 1 undergoes SCO at a high temperature(T_(1/2)=410 K for the fresh sample and T_(1/2)=406 K for the dried sample),while complex 2 displays near room temperature SCO(T_(1/2)=283 K for the fresh sample and T_(1/2)(↑)=283 K and T_(1/2)(↓)=257 K for the dried sample).To the best of our knowledge,complex 1 has the highest transition temperature reported among trinuclear SCO complexes so far,which is a remarkable feature of multinuclear materials.Slight structural modifications tend to upend the SCO behavior which paves the way for fine tuning SCO.展开更多
Treatment of a heptadentate ligand 2,2＇-（（（pyridine-2,6-diyl-bis（methylene））- bis（（pyridin-2-ylmethyl）azanediyl））bis（methylene））diphenol （H2L） possessing pyridinyl- and phenolate groups, with three eq...Treatment of a heptadentate ligand 2,2＇-（（（pyridine-2,6-diyl-bis（methylene））- bis（（pyridin-2-ylmethyl）azanediyl））bis（methylene））diphenol （H2L） possessing pyridinyl- and phenolate groups, with three equivalents of Cu（C104）2·6H2O in methanol under base conditions, gave rise to a hexanuclear cluster complex [Cu6L2（OH）4]（C104）4·4MeCN·0.5MeOH （1）. Complex 1 crystallizes in triclinic, space group Pi with a = 12.068（12）, b = 12.567（12）, c = 16.279（16） A, α = 105.694（12）, β = 93.631（13）, γ = 112.017（11）°, V= 2166（4） A3, Z = 1,μ= 1.651 mm^-1, Dc = 1.599 Mg/m^3, T = 296（2） K, C74.5H795N14O24.5Cl4Cu6, Mr = 2086.12, F（000） = 1062.5, S = 1.061, R = 0.0521 and wR = 0.1270. In the cation of complex 1, the six copper cores are arranged into a two-parallel three-site strings configuration with each metal exhibits a slightly distorted square-pyramidal geometry, resulting from the connection of donor pyridinyi nitrogen and phenolate oxygen atoms in ligand H2L, and/or the oxygen donors in hydroxyl groups. In addition, magnetic susceptibility measurements revealed complex 1 displayed antiferromagnetic coupling.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,21971124 and 22035003).
文摘Spin-crossover(SCO)complexes have been extensively studied in the past few decades owing to their bistable nature which find application in a myriad of areas.In order to enhance and optimize the SCO behavior,considerable attention is being paid towards the synthesis of discrete multinuclear spin-crossover complex systems.Here,two mixed-valence Fe_(2)^(Ⅲ)Fe^(Ⅱ)trinuclear complexes of the formula{[Fe^(Ⅱ)(TPMA)][Fe^(Ⅲ)(TpR)(CN)_(3)]_(2)}·MeOH·2H_(2)O(1)and{[Fe^(Ⅱ)(TPMA)][Fe^(Ⅲ)(TpR)(CN)_(3)]_(2)}·H_(2)O(2)[where TPMA=tris(2-pyridylmethyl)amine,Tp=tris(pyrazol-1-yl)borate,R=3,5-dimethyl for 1 and H for 2]were synthesized and characterized.Magnetic measurements confirmed that complex 1 undergoes SCO at a high temperature(T_(1/2)=410 K for the fresh sample and T_(1/2)=406 K for the dried sample),while complex 2 displays near room temperature SCO(T_(1/2)=283 K for the fresh sample and T_(1/2)(↑)=283 K and T_(1/2)(↓)=257 K for the dried sample).To the best of our knowledge,complex 1 has the highest transition temperature reported among trinuclear SCO complexes so far,which is a remarkable feature of multinuclear materials.Slight structural modifications tend to upend the SCO behavior which paves the way for fine tuning SCO.
基金Financially supported by the Education Department of Jiangxi Province(No.JXJG-14-10-6)Jiangxi Science and Technology Normal University
文摘Treatment of a heptadentate ligand 2,2＇-（（（pyridine-2,6-diyl-bis（methylene））- bis（（pyridin-2-ylmethyl）azanediyl））bis（methylene））diphenol （H2L） possessing pyridinyl- and phenolate groups, with three equivalents of Cu（C104）2·6H2O in methanol under base conditions, gave rise to a hexanuclear cluster complex [Cu6L2（OH）4]（C104）4·4MeCN·0.5MeOH （1）. Complex 1 crystallizes in triclinic, space group Pi with a = 12.068（12）, b = 12.567（12）, c = 16.279（16） A, α = 105.694（12）, β = 93.631（13）, γ = 112.017（11）°, V= 2166（4） A3, Z = 1,μ= 1.651 mm^-1, Dc = 1.599 Mg/m^3, T = 296（2） K, C74.5H795N14O24.5Cl4Cu6, Mr = 2086.12, F（000） = 1062.5, S = 1.061, R = 0.0521 and wR = 0.1270. In the cation of complex 1, the six copper cores are arranged into a two-parallel three-site strings configuration with each metal exhibits a slightly distorted square-pyramidal geometry, resulting from the connection of donor pyridinyi nitrogen and phenolate oxygen atoms in ligand H2L, and/or the oxygen donors in hydroxyl groups. In addition, magnetic susceptibility measurements revealed complex 1 displayed antiferromagnetic coupling.
