Few spin-crossover materials with a 1D ladder-type structure have been reported.Previously,[Fe(Mebpt){Au(CN)_(2)}]·H_(2)O(MebptH=3-(5-methyl-2-pyridyl)-5-(2-pyridyl)-1,2,4-triazole)was made and shown to display g...Few spin-crossover materials with a 1D ladder-type structure have been reported.Previously,[Fe(Mebpt){Au(CN)_(2)}]·H_(2)O(MebptH=3-(5-methyl-2-pyridyl)-5-(2-pyridyl)-1,2,4-triazole)was made and shown to display gradual spin-crossover behaviour.In the current work,a new 1D iron(Ⅱ)ladder-type compound,[Fe(bpt){Au(CN)_(2)}](bptH=3-(2-pyridyl)-5-(2-pyridyl)-1,2,4-triazole),was produced and showed enhanced spin-crossover behavior.It showed an abrupt spin transition above room temperature with a 3 K hysteresis(T_(1/2)↓=335 K and T_(1/2)↑=338 K).The origin of its enhanced spin-crossover could be ascribed to a greater influence of supramolecular interactions over the electronic substituent effect.展开更多
Dynamic molecular materials,which involvemechanical motions in crystals,usually exhibit tunable properties related to conformational polymorphs.Herein,we describe a solvent-free molecular crystal[{FeⅢ(salten)}2(TPB)]...Dynamic molecular materials,which involvemechanical motions in crystals,usually exhibit tunable properties related to conformational polymorphs.Herein,we describe a solvent-free molecular crystal[{FeⅢ(salten)}2(TPB)](BPh_(4))_(2)(Ⅰ)developed by associating the rotatable tetraphenylborate anion with the spin crossover(SCO)binuclear iron(Ⅲ)cation.The solvent-free phaseⅠcan undergo a temperature-induced phase transformation to phaseⅡ,during which rotation of the BPh4−anion interplays with the SCO component,giving rise to fascinating variations in SCO(from gradual to abrupt)and dielectric properties.Most importantly,an unexpected polymorphic transformation fromⅡtoⅢorⅣ,with increasing magnetic hysteresis,is realized by exposingⅡto water or ethanol vapor;the transition is reversible by heating.This rare successive transformation is further rationalized by theoretical calculations.Hence,this multiresponse system provides a new way for modulating synergistic effects and designing dynamic SCO materials by integrating intramolecular motions in the crtystal lattice.展开更多
基金supported by the NSFC(21373279,21501067,21601002 and 91422302)the Zhejiang Provincial Natural Science Foundation of China(Grant LQ15B010002)+1 种基金the Program for Science and Technology of Jiaxing(2015AY11011)the Start-up Grant from Jiaxing University(no.70514017).
文摘Few spin-crossover materials with a 1D ladder-type structure have been reported.Previously,[Fe(Mebpt){Au(CN)_(2)}]·H_(2)O(MebptH=3-(5-methyl-2-pyridyl)-5-(2-pyridyl)-1,2,4-triazole)was made and shown to display gradual spin-crossover behaviour.In the current work,a new 1D iron(Ⅱ)ladder-type compound,[Fe(bpt){Au(CN)_(2)}](bptH=3-(2-pyridyl)-5-(2-pyridyl)-1,2,4-triazole),was produced and showed enhanced spin-crossover behavior.It showed an abrupt spin transition above room temperature with a 3 K hysteresis(T_(1/2)↓=335 K and T_(1/2)↑=338 K).The origin of its enhanced spin-crossover could be ascribed to a greater influence of supramolecular interactions over the electronic substituent effect.
基金supported by the National Key Research and Development Program of China(2018YFA0306001)the NSFC(21773316,21771200,and 21821003)+2 种基金the Pearl River Talent Plan of Guangdong(2017BT01C161)The scientific grants R-143-000-A80-114 and R-143-000-A65-133 fromNational University of Singapore are gratefully acknowledged.Computational resources from NSCC(ASPIRE-1,grant no.11001278)were used for this study.
文摘Dynamic molecular materials,which involvemechanical motions in crystals,usually exhibit tunable properties related to conformational polymorphs.Herein,we describe a solvent-free molecular crystal[{FeⅢ(salten)}2(TPB)](BPh_(4))_(2)(Ⅰ)developed by associating the rotatable tetraphenylborate anion with the spin crossover(SCO)binuclear iron(Ⅲ)cation.The solvent-free phaseⅠcan undergo a temperature-induced phase transformation to phaseⅡ,during which rotation of the BPh4−anion interplays with the SCO component,giving rise to fascinating variations in SCO(from gradual to abrupt)and dielectric properties.Most importantly,an unexpected polymorphic transformation fromⅡtoⅢorⅣ,with increasing magnetic hysteresis,is realized by exposingⅡto water or ethanol vapor;the transition is reversible by heating.This rare successive transformation is further rationalized by theoretical calculations.Hence,this multiresponse system provides a new way for modulating synergistic effects and designing dynamic SCO materials by integrating intramolecular motions in the crtystal lattice.
