Solvothermal synthesis of novel antimony sulphides containing [Sb4S7]2− units

Two new antimony sulphides have been prepared solvothermally and characterised by single-crystal X-ray diffraction. [Co(en)3][Sb4S7] (1) was prepared at 140 °C from CoS, Sb2S3 and S in the presence of ethylenediamine, whilst heating a mixture of Sb2S3, Co and S in tris(2-aminoethyl)amine, N(CH2CH2NH2)3, at 180 °C results in the formation of [C6H20N4][Sb4S7] (2). Both materials contain [Sb4S7]2− chains formed from linkage of cyclic Sb3S63− units by SbS33− pyramids. In (1), the [Sb4S7]2− chains are linked by secondary Sb–S interactions to form sheets, between which the charge balancing [Co(en)3]2+ cations reside. The structure of (2) involves interconnection of pairs of [Sb4S7]2− chains through Sb2S2 rings to form isolated [Sb4S7]2− double chains which are interleaved by protonated template molecules.