Synthesis, spectroscopic and structural characterisation of Cd(II) and Zn(II) derivatives of tris(3,4,5-trimethylpyrazol-1-yl)methane

The reactions between MX2 (M=Zn or Cd, X=ClO4, NO3, Cl, Br, I and CH3COO) and excess of tris(3,4,5-trimethylpyrazol-1-yl)methane ligand (L) yield [MX2(L)]- or [M(L2)]X2-type complexes, the ligand to metal ratio being dependent on the nature of the counterion X. All complexes have been characterised in the solid state (IR) as well as in solution (NMR (1H, 13C and 113Cd), electrospray ionisation mass spectroscopy and conductivity measurements). The solid-state structures of [Cd(L)2](NO3)2 · 1/2H2O · 3CH2Cl2, [M(L)2](ClO4)2·4CH2Cl2 (M=Zn, Cd) (isomorphous) and [Zn(L)2](ClO4)2·4CH2Cl2 have been determined by single-crystal X-ray studies, which are consistent with the presence of octahedral centrosymmetric cations of the form [M(L)2]2+ with perchlorate or nitrate counterions.