YCu(TeO3)2(NO3)(H2O)3: a novel layered tellurite.

A new hydrated yttrium copper tellurite nitrate, yttrium(III) copper(II) bis[trioxidotellurate(IV)] nitrate trihydrate, has been synthesized hydro-thermally in a Teflon-lined autoclave and structurally determined using synchrotron radiation. The new phase is the first example containing yttrium, copper and tellurium in one structure. Its crystal structure is unique, with relatively strongly bound layers extending parallel to (020), defined by YO8, CuO4 and TeO3 polyhedra, while the NO3- anions and one third of the water molecules lie between those layers. The structural unit consists of [Cu2(TeO3)4]4- loop-branched chains of [Cu⋯Te⋯Cu⋯Te} squares running parallel to [001], which are linked further into layers only through Y(O,H2O)8 polyhedra. Weak 'secondary' Te bonds and O-H⋯O hydrogen-bonding interactions, involving water molecules and layer O atoms, link the layers and interlayer species. IR spectroscopic data are also presented. [ABSTRACT FROM AUTHOR]