Ashish R. Naik

Synthesis and structural characterization of tris (ethylenediamine)nickel(II) dichromate

The reaction of tris(ethylenediamine)nickel(II) dichloride dihydrate with potassium dichromate or potassium chromate results in the formation of mixed metallic compounds tris(ethylenediamine)nickel(II) dichromate [Ni(en)3][Cr2O7] (1) (en = ethylenediamine) and tris(ethylenediamine)nickel(II) chromate [Ni(en)3][CrO4] (2). Both compounds were characterized by analysis, spectra, magnetic susceptibility, and the structure of 1 was determined. [Ni(en)3][Cr2O7] (1) crystallizes in the centrosymmetric monoclinic space group P2(1)/c and its structure consists of a [Ni(en)3]2+ dication and a dichromate dianion, with all the atoms situated in a general position. Two carbons of one coordinated (en) in 1 and the hydrogens attached to the amine nitrogen in the same ligand are disordered over two positions. In the crystal structure, tris(ethylenediamine)nickel(II) cations are linked to the [Cr2O7]2− anions with several weak hydrogen bonding interactions resulting in an extended network. The χ versus T plots of 1 and 2 reveal simple paramagnetic behavior.

Bis(isopropyl­ammonium) tetra­sulfido­molybdate(VI)

The title compound, (C3H10N)2[MoS4], was synthesized by passing a rapid stream of H2S into an aqueous isopropylamine solution of molybdic acid. The title compound is isotypic with the corresponding W analogue (C3H10N)2[WS4]; its structure consists of a slightly distorted tetrahedral [MoS4]2− dianion and two crystallographically independent isopropylammonium cations, with all atoms located in general positions. The cations and anion are linked by weak N—H⋯S and C—H⋯S interactions, the strength and number of which can explain the observed Mo—S bond distances.

Piperazinium dichromate(VI)

The structure of the title complex, (C4H12N2)[Cr2O7], consists of dichromate dianions which are connected to the cyclic organic piperazinium (pipH2)2+ dications via hydrogen bonding. There are two crystallographically independent piperazinium dications, both located on centres of inversion, while the anions are located in general positions.

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

AbstractThe 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(μ2-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. Graphical AbstractSynthesis, structure, photochemistry and redox characteristics of hexakis(butan-1-aminium) heptamolybdate(VI) tetrahydrate are reported.