The crystal engineering of octacyanidomolybdate(Ⅳ)ions and copper(Ⅱ)complexes with two types of chelating ligands:multidentate blocking ligand,tren=(tris(2 aminoethyl)amine),and bidentate ligand capable of forming u...The crystal engineering of octacyanidomolybdate(Ⅳ)ions and copper(Ⅱ)complexes with two types of chelating ligands:multidentate blocking ligand,tren=(tris(2 aminoethyl)amine),and bidentate ligand capable of forming unusual organic bridges,tn=1,3-diaminopropane,resulted in the formation of{[Cu(tren)]2(μ-tn)}·[Mo(CN)8]·7.5H2O(1)and{[Cu(tren)]2(μ-tn)}·[Mo(CN)8]·{[Cu(tren)]2[Mo(CN)8]}·9H2O(2).The crystal structure of 1 comprises isolated anions[Mo(CN)8]4-wrapped with charge-compensating units{[Cu(tren)]2(μ-tn)}^(4+)stabilised by extensive H-bond networks.Compound 2 forms alternating layers consisting of the same ions as 1 and neutral cyanido-bridged V-shaped trinuclear molecules{[Cu(tren)]2[Mo(CN)8]}.Additionally,two previously reported V-shaped trinuclear reference systems were synthesised:[Cu(tn)2]2[Mo(CN)_(8)]·2H_(2)O(3)and[Cu(tren)]2[Mo(CN)8]·5.25H2O(4).UV–Vis–NIR absorption spectroscopy,supported by quantum chemical calculations(DFT and TD-DFT),confirmed the presence of Mo(Ⅳ)to Cu(Ⅱ)charge transfer bands centred on trinuclear molecules(2–4)and their absence for the ionic sample 1 without CN^(-)-bridges.Additionally,detailed descriptions of the energy level diagrams of 1–4 with the frontier molecular orbitals and possible optical transitions were made.Magnetic studies indicated paramagnetic behaviour with weak antiferromagnetic interactions at low temperature.Finally,photomagnetic studies of 1–3 showed the increase of magnetization after irradiation with 473 and 410 nm light at 10 K.Comparative analysis of all data suggests that the photomagnetic effect in 1 is well described by the lightinduced excited spin-state trapping(LIESST)effect in the Mo(Ⅳ)centre,while other cyanido-bridged compounds prefer the metal-to-metal charge transfer with minor contribution of LIESST effects.展开更多
基金supported in part by a JSPS Grant-in-Aid for Scientific Research(A)(Grant Number JP20H00369)a Grantin-Aid for Scientific Research on Innovative Area Soft Crystals(Area No.2903,JP17H06367)+4 种基金Grant-in-Aid for Specially Promoted Research(Grant Number JP15H05697)IM–LED LIA(CNRS)and CNRS-University of Tokyo“Excellence Science”Joint Research ProgramWe also acknowledge the Cryogenic Research Center,The University of Tokyo,the Center for Nano Lithography&Analysis,The University of Tokyo supported by MEXT,and the MEXT Quantum Leap Flagship Program(Grant Number JPMXS0118068681)for supportK.K.is grateful for a Grant in-Aid for JSPS fellows(Grant Number JP20J20245)O.S.is grateful for JSPS KAKENHI Grant Number JP21K14582.
文摘The crystal engineering of octacyanidomolybdate(Ⅳ)ions and copper(Ⅱ)complexes with two types of chelating ligands:multidentate blocking ligand,tren=(tris(2 aminoethyl)amine),and bidentate ligand capable of forming unusual organic bridges,tn=1,3-diaminopropane,resulted in the formation of{[Cu(tren)]2(μ-tn)}·[Mo(CN)8]·7.5H2O(1)and{[Cu(tren)]2(μ-tn)}·[Mo(CN)8]·{[Cu(tren)]2[Mo(CN)8]}·9H2O(2).The crystal structure of 1 comprises isolated anions[Mo(CN)8]4-wrapped with charge-compensating units{[Cu(tren)]2(μ-tn)}^(4+)stabilised by extensive H-bond networks.Compound 2 forms alternating layers consisting of the same ions as 1 and neutral cyanido-bridged V-shaped trinuclear molecules{[Cu(tren)]2[Mo(CN)8]}.Additionally,two previously reported V-shaped trinuclear reference systems were synthesised:[Cu(tn)2]2[Mo(CN)_(8)]·2H_(2)O(3)and[Cu(tren)]2[Mo(CN)8]·5.25H2O(4).UV–Vis–NIR absorption spectroscopy,supported by quantum chemical calculations(DFT and TD-DFT),confirmed the presence of Mo(Ⅳ)to Cu(Ⅱ)charge transfer bands centred on trinuclear molecules(2–4)and their absence for the ionic sample 1 without CN^(-)-bridges.Additionally,detailed descriptions of the energy level diagrams of 1–4 with the frontier molecular orbitals and possible optical transitions were made.Magnetic studies indicated paramagnetic behaviour with weak antiferromagnetic interactions at low temperature.Finally,photomagnetic studies of 1–3 showed the increase of magnetization after irradiation with 473 and 410 nm light at 10 K.Comparative analysis of all data suggests that the photomagnetic effect in 1 is well described by the lightinduced excited spin-state trapping(LIESST)effect in the Mo(Ⅳ)centre,while other cyanido-bridged compounds prefer the metal-to-metal charge transfer with minor contribution of LIESST effects.
