Novel copper(I)-thioantimonales(III):: Solvothermal synthesis, crystal structures, thermal stability and magnetic properties of (C2N2H10)0.5Cu2SbS3, (C3N2H12)0.5Cu2SbS3, and (C4N2H14)0.5Cu2SbS3

The novel copper(I)-thioantimonates(III) (enH(2)(2+))(0.5)Cu2SbS3 (1) (en = ethylendiamine), (1,3-DAPH(2)(2+))(0.5)-Cu2SbS3 (11) (1,3-DAP = 1,3 diaminopropane) and (1,4-DABH(2)(2 +))(0.5)Cu2SbS3 (III) (1,4-DAB = 1,4-diaminobutane) were synthesized under solvothermal conditions reacting Sb2S3, CuCl2.2H(2)O, S with the amines. The compounds crystallize in the monoclinic space group P2(1)/n. The primary building units are a SbS3 trigonal pyramid and two distorted CuS3 units. In the structures the SbS3 pyramid is connected to six CuS3 moieties and every S atom has bonds to one Sb atom and to two Cu atoms. Further interconnection leads to the formation of ten-membered (10 MR) Cu3Sb2S5 and six-membered (6 MR) Cu2SbS3 rings. Every 10 MR is condensed to four 10 MR and four 6 MR to form a single layer within the (010) plane. Two such single layers are connected to a double layer thus forming the final [Cu2SbS3](-) layered anion. The [CuSbS3](-) protonated amines are located between the layers and the interlayer spacing depends on the size and orientation of these amines. Between the Sb atom and one Cu atom a remarkable short distance of about 2.7 Angstrom is observed. At elevated temperatures the compounds decompose into CuSbS2 and Cu3SbS4 suggesting a complex redox reaction. Diamagnetic susceptibilities indicate the copper(I) in the metal sulfide frameworks. All three compounds are semiconductors with intermediate band gaps of about 2 eV.