Hydrothermal synthesis and structure of a molybdenum(VI) phosphate cluster and a three dimensional cobalt molybdenum(V) phosphate

Abstract

Two new molybdenum phosphates, [Co(en) 3][C 4H 12N 2] 0.5[(Mo 5O 15)(HOPO 3) 2] · 3H 2O ( 1) (en = ethylenediamine) and (C 4N 2H 10) 5[Co 3Mo 12O 18(HOPO 3) 6(PO 4) 2(OH) 12(H 2O) 4] · 9H 2O ( 2), have been synthesized hydrothermally. 1 is constructed from [Mo 5P 2O 21(OH) 2] 4− clusters, Co(en) 3 3+ and piperazine, which are linked together through hydrogen-bonding interactions. The enantiomers of Co(en) 3 3+ in 1 are separated as Δ and Λ configurations. 2 is composed of centrosymmetric Co[Mo 6O 9(OH) 6(HOPO 3) 3(PO 4)] 2 clusters linked by dinuclear cobalt cations forming a three dimensional structure. The interconnected voids and channels in 2 are filled with piperazine and water molecules. The three dimensional 2 was obtained from the zero dimensional 1 under hydrothermal reaction conditions. This experiment demonstrates that molybdenum phosphates of low dimensional structure could be employed as starting materials to prepare molybdenum phosphates of high dimensional structure.