SYNTHESIS AND CRYSTAL-STRUCTURES OF 3 ZINC (CHLOROMETHYL)PHOSPHONATES

Reaction of zinc compounds with (chloromethyl)phosphonic acid yielded three novel layered compounds. Zn(O3-PCH2Cl).H2O was prepared from zinc acetate and the phosphonic acid at 70-degrees-C. It is monoclinic, space group P2(1)/n, with a = 4.781(2) angstrom, b = 19.816(8) angstrom, c = 5.6975(8) angstrom, beta = 91.91(2)-degrees, and Z = 4. This compound has a layered structure similar to that of Zn(O3PC6H5)-H2O.1 Addition of urea to the reaction mixture yielded another layered product in which urea is coordinated to zinc through oxygen. The compound is monoclinic, P2(1)/c, with a = 5.040(3) angstrom, b = 8.522(3) angstrom, c = 17.401(2) angstrom, beta = 89.80(2)-degrees, and Z = 4. The zinc atom is tetrahedrally coordinated by three phosphonate oxygens and one from urea. The phosphonate oxygens bridge across two zinc atoms forming a chain of eight-membered rings running parallel to the a-axis. The chains are linked together through hydrogen bonding along the b-axis to form the layers. Zn2Cl(O3PCH2Cl)(HO3PCH2Cl).h2O was prepared at 60-degrees-C from a mixture of ZnCl2 and (chloromethyl)phosphonic acid. The crystals are orthorhombic, Pbca, with a = 19.500(4) angstrom, b = 17.686(3) angstrom, c = 8.198(1) angstrom, and Z = 8. Zinc atoms are both tetrahedrally and octahedrally coordinated. The latter type of Zn atoms are joined in a cluster of two by bridging phosphonate oxygens forming four-membered rings. Each of these Zn atoms is bridged in the opposite direction by phosphonate groups tetrahedrally coordinated Zn atoms. The octahedra are completed by three water molecules. A chlorine atom is bonded directly to the tetrahedral zinc. The phosphonate bridging of metal atoms forms 14-membered rings and 12-membered rings in addition to the 4-membered rings. Each of the interlayer distances are determined by the way in which the chloromethyl group is situated in the interlamellar space.