2 NEW ADAMITE-TYPE PHASES, CO-2(OH)PO4 AND ZN-2(OH)PO4 - STRUCTURE-DIRECTING EFFECT OF ORGANIC ADDITIVES

The hydrothermal syntheses, X-ray single crystal structures, and certa in properties of cobalt hydroxyphosphate, Co-2(OH)PO4, and zinc hydrox yphosphate, Zn-2(OH)PO4, are described. Both materials are isomorphous with the adamite-type M(2)(OH)XO(4) structure, and consist of a conde nsed vertex- and edge-sharing network of MO(5), distorted MO(6)(M = Co , Zn), and PO4 subunits. Both snythetic procedures required the presen ce of organic reagents which are not incorporated into the crystalline reaction products. Crystal data: Co-2(OH)PO4, M(r) = 229.84, orthorho mbic, space group Pnnm (No. 58), a = 8.042(3) Angstrom, b = 8.369(2) A ngstrom, c = 5.940(2) Angstrom, V = 399.80 Angstrom(3), Z = 4, R = 2.4 0%, and R(w) = 2.71% (589 observed reflections with I > 3 sigma(I)). Z n-2(OH)PO4, M(r) = 242.74, orthorhombic, space group Pnnm(No. 58), a = 8.103(2), Angstrom, b = 8.3292(9) Angstrom, c = 5.9659(8) Angstrom, V = 402.65 Angstrom(3), Z = 4, R = 3.58%, and R(w) = 3.90% (708 data wi th I > 3 sigma(I)). (C) 1995 Academic Press, Inc.