Hysteretic vapour response of a heterodinuclear platinum(II)-copper(II) complex derived from the dimer-of-dimer motif and the guest-absorbing site

• Published in: Dalton transactions : an international journal of inorganic chemistry 2014-05, Vol.43 (20), p.7514-7521
• Main Authors: Ohba, Tadashi, Kobayashi, Atsushi, Chang, Ho-Chol, Kouyama, Takahiko, Kato, Tatsuhisa, Kato, Masako
• Format: Article
• Language: English
• Subjects: ACETONE; Color; Colour; COPPER COMPOUNDS; EROSION; Hysteresis; MECHANICAL HYSTERESIS; Methyl alcohol; MONOMERS; SOLVENTS; Vapour; X RAYS
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c4dt00316k

A heterodinuclear complex, syn-[PtCu(μ-pyt)2(bpy)2](2+) (syn-[PtCu]; Hpyt = pyridine-2-thiol, bpy = 2,2'-bipyridine), was synthesized by stepwise complexation. Three different crystal structures of the hexafluorophosphate salts with solvent molecules as guests at the axial sites of the Cu(ii) ions, i.e. syn-[PtCu-G] (G = acetonitrile, acetone, and methanol), were determined by X-ray analyses. In the solid-state, these complexes adopt dimer-of-dimer motifs characteristic of the syn isomers of dinuclear complexes with two pyt bridging ligands arranged in a head-to-head configuration. These dinuclear complexes have a short PtCu distance (2.75-2.81 Å) and slightly different intermolecular PtPt distances (3.43-3.51 Å), which affect the colour of the solid complexes. All the syn-[PtCu-G] systems absorbed/desorbed vapour molecules; however, they exhibit different chromic changes because of the unique structural hysteresis of the desorbed form, i.e. syn-[PtCu], according to powder X-ray diffraction measurements. In addition, guest exchange occurred in the syn-[PtM-G] complexes upon exposure to the vapour of different solvents.