NEW COPPER(II)LEAD(II) HETEROTETRANUCLEAR COMPLEX: DIRECT SYNTHESIS AND STRUCTURE. Olga Yu.Vassilyeva, Larisa A.Kovbasyuk, Dept of Chemistry, Kiev Shevchenko University, Volodimirska, 64, Kiev 252033, Ukraine

Method of direct synthesis was succesfully applied for the preparation of a number of the heteronuclear Cu^IIPb^II complexes containing aminoalkohols. The structure of the heterotetranuclear Cu^IIPb^II complex containing 2-dimethylaminoethanol (HL) was solved by direct methods and refined by full-matrix least-squares computations to R=0.0438 for the 2359 reflections with I >2[[sigma]](I). The crystal of the compound comprises dimeric centrosymmetric molecules {Cu₂Pb₂[(CH₃)₂NCH₂CHO]₄I₄(DMSO)₂} bridged by oxygen atoms of chelated L-groups, and DMSO molecules of crystallization in the lattice cavities. The copper co-ordination environment formed by oxygen and nitrogen atoms of the two co-ordinated L-groups (appropriate bond distances are 1.914(8) - 2.07(1) Å) has somewhat distorted square planar geometry. The close lead atom co-ordination environment is formed by three oxygen atoms of L-groups and oxygen atom of co-ordinated DMSO molecule; appropriate bond distances are 2.343(7) - 2.601(7) Å. The remote iodine atoms, located at a distance from the lead atom of 3.285(1) - 3.390(1) Å, complete co-ordination of lead to give a highly distorted octahedral configuration. The Pb---I(2) distance is elongated compared with Pb---I(1) one probably because of the bridging of the I(2) to the copper atom. Pb---Cu separations (3.394 (2) and 3.634 (2) Å) are similar to those of known Cu^IIPb^II complexes of macrocycles (3.344(3) - 3.577(2) Å). Oxygen atoms of L-groups bridging both metal centres arrange a strictly planar central Pb₂O₂ rhombus in the structure of the complex.

{Cu₂Pb₂[(CH₃)₂NCH₂CHO]₄I₄(DMSO)₂} .2DMSO crystallizes in the triclinic space group P-1 with a=8.305(3), b=12.132(3), c=12.755(3) Å, [[alpha]]=84.86(2), b=80.79(3) and [[gamma]]=73.26(3)deg., with two formula units per primitive unit-cell.