THE CRYSTAL-STRUCTURE OF (N,N-DIETHYL-N'- BENZOYLSELENOUREATO)THALLIUM(I)

Tl(C12H15N2OSe) exists in a dimeric form and crystallizes in the tricl inic space group P-1. The cell parameters are a = 6.501(6), b = 9.901( 7), c = 12.233(9) angstrom, alpha = 91.59(2), beta = 80.11(6), gamma = 85.28(5)degrees and Z = 2. The structure was solved with Patterson an d direct methods and was refined to a final R-value of 5.30%. Two comp lex molecules are connected by Tl-Se bonds to form a planar four membe red ring with diagonally arranged Tl and Se atoms. The considerably be nded chelate rings are nearly at right angle to the central four membe red ring. The Tl-Se bond lengths are 3.105(3) and 3.118(3) angstrom, t he TI-O bond length is 2.532(9) angstrom.