Zinc thiosemicarbazide dicarboxylates: the influence of the anion shape on supramolecular structure

The syntheses and crystal structures of the zinc thiosemicarbazide dicarboxylate compounds [Zn(tsc)(2)(OH2)(2)][fumarate] 2, [Zn(tsc)(2)(citraconate)].H2O 3, [Zn(tsc)(mu-1,4-phenylenediacetate)] 4, [Zn(Ettsc)(2)(citraconate).3H(2)O 5, [Zn(Ettsc](2)(Hphthalate)][Hphthalate].H2O 6, [Zn(Metsc)(2)(Hphthalate)][Hphthalate].H2O 7, [Zn(Me(2)tsc)(2)(OH2)][terephthalate].2H(2)O 8 and [Zn(EtMe2-tsc-2(OH2)][terephthalate] 9 are reported. The supramolecular structures of the terephthalate and fumarate compounds 2, 8 and 9 consist of chains of cations and anions, in which the ions are linked by hydrogen bonding. In contrast, compounds 3, 5, 6 and 7 contain carboxylate groups co-ordinated to the metal centre to give either neutral or monocationic species. These differences can be rationalised on the basis of the dicarboxylate structure, in particular the angle between the carboxylate vectors. Compound 4 forms co-ordination polymers in an analogous manner to thiourea derivatives. (C) 2002 Elsevier Science Ltd. All rights reserved.