Metal phosphonates containing pyridyl N-oxide groups: Syntheses of Cd{l_brace}(2-C{sub 5}H{sub 4}NO)CH(OH)PO{sub 3}{r_brace}(H{sub 2}O){sub 2} and Zn{l_brace}(4-C{sub 5}H{sub 4}NO)CH(OH)PO{sub 3}{r_brace} with chain and layer structures

This paper reports the syntheses and characterization of two phosphonate compounds Cd{l_brace}(2-C{sub 5}H{sub 4}NO)CH(OH)PO{sub 3}{r_brace}(H{sub 2}O){sub 2} (1) and Zn{l_brace}(4-C{sub 5}H{sub 4}NO)CH(OH)PO{sub 3}{r_brace} (2) based on hydroxy(2-pyridyl N-oxide)methylphosphonic and hydroxy(4-pyridyl N-oxide)methylphosphonic acids. Compound 1 has a chain structure in which dimers of edge-shared {l_brace}CdO{sub 6}{r_brace} octahedra are linked by {l_brace}CPO{sub 3}{r_brace} tetrahedra through corner-sharing. The pyridyl rings reside on the two sides of the inorganic chain. Compound 2 has a layer structure where the inorganic chains made up of corner-sharing {l_brace}ZnO{sub 4}{r_brace} and {l_brace}CPO{sub 3}{r_brace} tetrahedra are covalently connected by pyridyl N-oxide groups. Crystal data for 1: triclinic, space group P1-bar , a=6.834(1)A, b=7.539(1)A, c=10.595(2)A, {alpha}=84.628(3){sup o}, {beta}=74.975(4){sup o}, {gamma}=69.953(4){sup o}. For 2: triclinic, space group P1-bar , a=5.219(1)A, b=8.808(2)A, c=9.270(2)A, {alpha}=105.618(5){sup o}, {beta}=95.179(4){sup o}, {gamma}=94.699(4){sup o}.