Hydrothermal synthesis of a one-dimensional bimetallic, mixed valence oxide [{Cu4(terpy)4(PO4)(H2O)2}{W10(VI)W2(V)O36(PO4)}] · 5H2O, a material constructed from {PW12O40}5− and novel {Cu4(terpy)4(PO4)(H2O)2}5+ cluster building blocks

Abstract

The hydrothermal reaction of Na2WO4·2H2O, CuSO4·5H2O, 2,2′:6′,2″-terpyridine (terpy), H3PO4 and H2O at 150 °C for 120 h yielded a mixture of [{Cu4(terpy)4(PO4)(H2O)2}{W12O36(PO4)}]·5H2O (1·5H2O) and [{Cu(terpy)(H2O)2}2{W12O36(PO4)}]·6H2O (2·6H2O). The structure of 2 consists of discrete {W12O36(PO4)}4− Keggin clusters whose surface is decorated by two {Cu(terpy)(H2O)}2+ charge-compensating subunits. In contrast, the structure of 1 is one-dimensional with the chain constructed from {W12O36(PO4)}5− Keggin clusters and the cationic {Cu4(terpy)4(PO4)(H2O)2}5+ clusters. Both materials are mixed valence. In the case of 1, the tungstate core is formally {W10(VI)W2(V)}, while for 2 the oxidation states are {W11(VI)W(V)}. Crystal data: C30H27N6Cu2W6O24.5P (1·5H2O), monoclinic, C2/c, a=14.5025(6) Å, b=22.2102(9) Å, c=26.566(1) Å, β=101.813(1)°, V=8375.6(6) Å3, Z=8. C15H21N3CuO25W6P0.5 (2·6H2O), monoclinic, C2/c, a=17.6263(9) Å, b=16.6990(9) Å, a=22.944(1) Å, β=112.285(1)°, V=6249.0(6) Å3, Z=8.