Synthesis and Structures of Organically Modified Zinc Vanadates

School of Chemistry, Suranaree University of Technology* Department of Chemistry HKUST Hong Kong**
â—‹Samroeng Krachodnok* Kittipong Chainok* Kenneth J. Haller* Herman H-Y. Sung** Fanny L-Y. Shek** Ian D. Williams**

Exploration of the structural chemistry of organically modified zinc vanadates has been carried out through hydrothermal crystallization reactions of various organic bases with zinc acetate and vanadium pentoxide (V2O5) under different conditions of pH, stoichiometry, temperature, time and concentration. A wide variety of product types have been found in which either organic or complex cations crystallize with anionic vanadate chains for example [ZnIm4][VO3]2, or vanadate clusters as in 2[Zn(2-MeIm)4]2[2MeIm-H][V10O28]. Alternatively the organo-zinc and vanadate components may be connected as in the network solids [Zn(en)(VO3)2], or [Zn(Im)(Im)-VO3] containing [Im]- anions (shown in Fig). Finally even discrete molecular species such as [{Zn(2-MeIm)3}2V4O12] which is composed of a cyclotetravanadate ring with two pendant zinc tris-imidazolyl groups can be isolated in phase pure form. The Thai Research Fund (2002 RJG PhD scholarship to S.K.) and RGC (HK) are thanked for financial support of this work.