Some Factors and Effects on Thermally Structural Changes of Lattice for Cyanide-Bridged Bimetallic Assemblies of Cu(II)

In order to understand novel structural features of crystal packing of [CuL2][Ni(CN)4]·2H2O (L = (1R,2R)-1,2diaminocyclohexane), we have investigated temperature effect, metal-size effect, and isotope effect and their temperature dependence (100-300 K) with synchrotron powder X-ray diffraction (XRD) for (1) [CuL2][M(CN)4]·2H2O (M=Pd, Pt), (2) [CuL’2][M(CN)4] (M=Ni, Pd, and Pt; L’ = N-ethylethylenediamine), and (3) [CuL’’2][M(CN)6]·nH2O (L’’ =(1S,2S)-1,2dimethylcyclohexanediamine. M=Cr, Co, and Fe; isotopes of H2O are H(H), H(D), and O(O), respectively). The effect of the factors of (1) (temperature difference of 200 K) is comparable to metal size for the system of (1). Combinatorial preparation of (2) gave rise to the most stable Pd(II) complexes predominantly. Isotope effect of water molecules resulted in little structural changes of lattice for (3).