Solvothermal syntheses,and crystal structures of Chromiu(Ⅲ) complexes of AsS_3~(3-) ligand

【摘要】：Chalcogenidoarsenate materials have attracted much attention for their potential applications such as optical nonlinearity,electrical,and ion–exchange materials.1,2 Two new transition-metal thioarsenates[Cr(trien)(As S3)](1)and[Cr(en)2(As S3)](2)(en=ethylenediamine)were solvothermally prepared by reaction of Cr Cl3·6H2O with As2O3 and S in polyamines.In compound 1(Fig.1),The As atom binds three S(S1,S2,and S3)atoms,forming a typical trigonal pyramid[As S3]3-.One tetradentate trien ligands coordinate to the Cr3+ion,yielding the four-coordinated complex cation[Cr(trien)]3+,The[As S3]3-anion binds with the Cr3+ion of[Cr(trien)]3+as aη2-As S3 bidentate chelating ligand via S1 and S2,forming the neutral complexes[Cr(trien)(As S3)].In 2 the Cr3+ion is coordinated by two bidentate en ligands,forming the cation[Cr(en)2]3+.The[As S3]3-anion also acts as aη2-As S3 bidentate bridging ligand to link[Cr(en)2]3+cations into a neutral complex[Cr(en)2(As S3)].The N-H···S hydrogen bonding interactions among the[Cr(trien)(As S3)]moieties result in a 2D layer parallel to the bc plane(Fig.2).Solid-state optical absorption spectra of compounds 1 and 2 were recorded using powder samples at room temperature.The complexes exhibit well-defined steep absorption edges from which the band gaps(Eg)can be estimated as 1.57,1.69 e V for 1 and 2,respectively(Fig.3).