Cation-anion interactions in bis(+/-)trans-2-aminocyclohexylammonium tetrathiotungstate, 1,7-diazonia-4-aza-heptane tetrathiotungstate and 1,5-diazonia-9-aza-nonane tetrathiotungstate

Abstract

The reaction of (NH(4))(2)[WS(4)] with (+/-) trans- 1,2-diaminocyclohexane (trans-1,2-cn), bis(2-aminoethyl)amine (dien) and bis(3-aminopropyl)amine (dipn) leads to the formation of the organic ammonium tetrathiotungstates (trans- 1,2-cnH)(2)[WS(4)] (1), (dienH(2))[WS(4)] (2) and (dipnH(2))[WS(4)] (3) [trans-1,2-cnH is (+/-)trans-2-aminocyclohexylammonium; dienH(2) is 1,7-diazonia-4-aza-heptane; dipnH(2) is 1,5-diazonia-9-aza-nonane] in good yields. The title complexes 1-3 react with [Ni(en)(3)](2+) (en = ethylenediamine) forming the highly insoluble complex [Ni(en)(3)][WS(4)]. The structure of the complexes 1-3 can be described as consisting of tetrahedral [WS(4)](2-) dianions which are linked to the monoprotonated cation of trans-1,2-cn in 1 and the diprotonated cations of then and dipn in 2 and 3, with the aid of weak hydrogen bonding interactions. The difference between the longest and the shortest W-S bond lengths Delta is 0.0104, 0.0170 and 0.0173 A in 1, 2 and 3, respectively. A comparative study of the structural features of several tetrathiotungstates is presented and the interactions between the organic cations and the tetrathiotungstate anions are discussed in terms of the magnitude of A, the difference between the longest and the shortest W-S bond distances.