The Oxovanadium–Organophosphonate System: Complex Cluster Structures [(VO)6(tBuPO3)8Cl], [(VO)4{PhP(O)2OP(O)2Ph}4Cl]−, and [V18O25(H2O)2(PHPO3)20Cl4]4− with Encapsulated Chloride Anions Prepared from Simple Precursors

Simply heating a suspension of [Ph4P][VO2Cl2] and tBuPO3H2 in acetonitrile in a sealed tube to 100°C gave the first of the three title compounds as dark green crystals. The structure of this compound (shown on the right) could not have a more pleasing simplicity. Relatively minor changes in the starting materials led to other, more complicated products.