Delicate Difference in Coordinating Nature between Copper(II) and Nickel(II) Ions. Structural Properties of Copper(II) and Nickel(II) Nitrate Containing 1,2-Bis(dimethyl-3-pyridylsilyl)ethane

Abstract

Studies on the molecular construction and structures of <TEX>$M(NO_3)_2$</TEX> (M = Cu(II), Ni(II)) complexes with 1,2-bis(dimethyl-3-pyridylsilyl)ethane (L) have been carried out. Formation of each molecular skeleton appears to be primarily associated with a suitable combination of bidentate N-donors of L and coordinating nature of octahedral metal(II) ions: [<TEX>$Cu(NO_3)_2(L)_2$</TEX>] yields a 2-dimensional sheet structure consisting of 44-membered <TEX>$Cu_4L_4$</TEX> skeleton whereas <TEX>$[Ni(L)_2(H_2O)_2](NO_3)_2$</TEX> produces an interpenetrated 3-dimensional structure consisting of 66-membered cyclohexanoid (<TEX>$M_6L_6$</TEX>) skeleton. The Cu(II) ion prefers nitrate whereas the Ni(II) ion prefers water molecules as the fifth and the sixth ligands.