Synthesis,Structure,and Optical-response Magnetic Property of a Heteroarene-azo Functionalized Mn,9 Cluster

Metal clusters with photoswitching ligands can undergo magnetic changes under light radiation,which makes them potential opti-cal-response magnetic-switching materials.Herein,a photoswitchable Mn-oxo cluster[Mn1Ⅱ15MnⅢ4(L)18(OH)12(N3)6](ClO4)2(C6H5CN)8,(Mn19azo,HL=1-(hydroxymethyl)-3,5-dimethyl-4-(phenyldiazenyl)-pyrazole)has been designed and synthesized to real-ize the photoswitching behavior.Mn19azo shows quick trans-to-cis transformation upon 365 nm light irradiation in CH2Cl2 solution and solid state as confirmed by UV-Vis spectra.After the powder sample was irradiated for 80 min,the Curie constant of Mn19azo increases by about 7％.The change of magnetic properties can be considered as the result of the change of intermolecular interac-tions.