TETRAHEDRAL-ATOM ZINCOPHOSPHATE STRUCTURES - ZINC DIETHYL PHOSPHATE, [ZN(O2P(OC2H5)2)2]X, A ONE-DIMENSIONAL INORGANIC POLYMER

The synthesis, structure, and some properties of a new, anhydrous, zinc ethyl phosphate are described. (OC2H5)2)2 (ZnPOEt) crystallizes in the monoclinic space group C2/c (No. 15) with a = 22.176 (6) angstrom, b = 8.042 (2) angstrom, c = 9.088 (3) angstrom, beta = 96.553 (8)-degrees, V= 1610 angstrom3, rho(calc) = 1.533 g/cm3, mu = 17.8 cm-1, and Z = 4, with R(F(o)) = 6.94% for 658 observed reflections (I > 3sigma(I)). The novel structure consists of infinite 1-dimensional chains of vertex-linked zinc-oxygen and phosphorus-oxygen tetrahedra forming ''four-rings'': two of the phosphate P-O vertices are coordinated to ethyl (-C2H5) groups, and the ''herringbone'' crystal packing is determined by van der Waals' forces between these terminal organic groups. Physical (TGA, DSC) and spectroscopic data (IR, H-1, and P-31 NMR) are presented. The physical data show a melting, followed by a decomposition reaction, eventually resulting in Zn(PO3)2. ZnPOEt is soluble in, and recrystallizable from, several polar and nonpolar solvents: the NMR data suggest that ZnPOEt maintains a ''polymeric'' state in solution. ZnPOEt is contrasted with its sulfur--containing analogue, Zn(S2P(OC2H5)2)2.