Synthesis, crystal structure and photochemistry of Hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate

Abstract

The synthesis, crystal structure, spectral characterization, photochemistry, electrochemical and thermal studies of the hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate (1) are reported. Dissolution of a mixed mono-hepta compound (BuNH3)8[(Mo7O24)(MoO4)] ⋅3H2O in water results in its transformation to the title compound viz., (BuNH3)6[Mo7O24] ⋅4H2O 1 (BuNH3= butan-1-aminium). The structure of the title compound consists of two crystallographically unique [Mo7O24]6− anions, twelve independent (BuNH3)+ cations and eight unique lattice water molecules, all of which are interlinked with the aid of three varieties of H-bonding interactions. Solar irradiation of 1 results in the formation of a bis(μ 2-oxo) bridged diheptamolybdate product. Electrochemical studies reveal the role of 1 in the photodimerization process. Thermal decomposition of 1 results in the formation of crystalline α-MoO3. Synthesis, structure, photochemistry and redox characteristics of hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate are reported.