Abstract:
The syntheses, crystal structures, spectral characterization, electrochemical, photoredox properties and biological studies of three sodium coordination polymers viz. (ImH) sub(4)[(Mu sub(2-)HMo sub(7)O sub(24))Na(H sub(2)O) sub(8)].7H sub(2)O 1 (Im = Imidazole), [(TEAH)Na sub(5)(H sub(2)O)12(Mu sub(5-)Mo sub(7)O sub(24))] sub(2) (TEA=triethanolamine) and [Na sub(2)(PyrH) sub(2)(Mu sub(2-)Mo sub(8)O sub(26))(H sub(2)O)7].8H sub(2)O 3 (Pyr = pyrazole) are reported. The unique Na atom in 1 exhibits ten coordination unlike hexa coordination observed in 2 and 3. The Mu sub(2-) bridging heptamolybdate (or octamolybdate) anion in 1 (or 3) links the sodium cations into an infinite chain resulting in a one-dimensional coordination polymer. In 2, the heptamolybdate anion exhibits an unprecedented Mu sub(5-) nonadentate binding resulting in a three- dimensional (3D) structure. Compounds 1-3 exhibit characteristic Raman bands. Solar irradiation of 2 results in photodimerization, which is further supported by electrochemical studies. Compounds 1-3 exhibit antibacterial activity, with 3 being the most effective against S. Pyogenes, followed by P. aeruginosa, S.typhi and S. aureus. Compound 3 exhibits excellent antidiabetic and anti-inflammatory properties. A comparative study of the binding modes of several heptamolybdates and octamolybdates based compounds is presented.
