PYRIDINESELENOLATE COMPLEXES OF TIN AND LEAD - SN(2-SENC5H4)(2), SN(2-SENC5H4)(4), PB(2-SENC5H4)(2), AND PB(3-ME(3)SI-2-SENC5H3)(2) - VOLATILE CVD PRECURSORS TO GROUP-IV GROUP-VI SEMICONDUCTORS

Pyridineseienolate forms stable homoleptic coordination compounds of S n(II), Sn(IV), and Pb(II). The complexes can be prepared either by met athesis or by insertion of the metal into the Se-Se bond of dipyriciyl diselenide, and they are soluble in coordinating solvents such as pyr idine. Isolation of the Pb(II) complex from both Pb(O) and Pb(IV) star ting materials indicates that the pyridineselenolate ligand cannot sta bilize Pb(IV). The compounds all sublime intact and decompose at eleva ted temperatures: the divalent complexes give MSe (M = Sn, Pb), while the Sn(IV) compound delivers SnSe2. In order to isolate a crystalline Pb compound, the 5-trimethylsilyl-2-pyridineselenolate ligand was prep ared. Attachment of the Me(3)Si functional group increases compound so lubility, and bads to the isolation of crystalline Pb(3-Me(3)Si-2-SeNC 5H2)(2). The structure of [Sn(2-SeNC5H4)(2)](2) (1) was determined by single-crystal X-ray diffraction and shown to be a dimer, with one che lating pyridineselenolate per Sn(II) and a pair of pyridineselenolates that asymmetrically span the two metal centers to form an eight membe red (-Sn-Se-C-N-Sn-Se-C-N-) ring, with weak Sn-Se interactions connect ing the dimeric units. Crystal data for 1 (Mo K alpha, 298(2) K): orth orhombic space group Pbca, a = 8214(1) Angstrom, b = 21.181(3) Angstro m, c = 14.628(2) Angstrom.