Thermochromism and Structure of Piperazinium Tetrachlorocuprate(II) Complexes

Mark J. Riley; Debora Neill; Paul V. Bernhardt; Karl A. Byriel; Colin H. L. Kennard

doi:10.1021/ic971612w

Thermochromism and Structure of Piperazinium Tetrachlorocuprate(II) Complexes

Inorg Chem. 1998 Jul 13;37(14):3635-3639. doi: 10.1021/ic971612w.

Authors

Mark J. Riley¹, Debora Neill, Paul V. Bernhardt, Karl A. Byriel, Colin H. L. Kennard

Affiliation

¹ Department of Chemistry, University of Queensland, Brisbane, 4072 Queensland, Australia.

PMID: 11670455
DOI: 10.1021/ic971612w

Abstract

The tetrachlorocuprate(II) ion can crystallize in two different structures with the piperazinium dication (pipzH(2)). Both structures contain discrete CuCl(4)(2-) species. A yellow compound (pipzH(2))[CuCl(4)].2H(2)O (1) is monoclinic (C2/c, Z = 4, a = 10.538(3) Å, b = 7.4312(5) Å, c = 17.281(4) Å, beta = 111.900(10) degrees ) and contains the CuCl(4)(2-) ion as a distorted tetrahedron. A green compound (pipzH(2))(2)[CuCl(4)].Cl(2).3H(2)O (2) is triclinic (P&onemacr;, Z = 2, a = 9.264(3) Å, b = 10.447(2) Å, c = 11.366(2) Å, alpha = 68.38 degrees, beta = 82.86(2) degrees, gamma = 83.05(2) degrees ) and contains the CuCl(4)(2-) ion with a square planar geometry. This latter compound shows thermo/photochromism, changing from green to yellow upon heating or laser irradiation.