Synthesis, spectral characterization and crystal structures of five organic ammonium tetrasulfidomolybdates

Abstract

The syntheses, spectral characterization and crystal structures of five organic ammonium tetrasulfidomolybdates namely (C sub(4)H sub(12)N) sub(2)[MoS sub(4)] 1 (C sub(4)H sub(12)N is 2-methyl-propan-2-aminium), (C sub(5)H sub(16)N sub(2))[MoS sub(4)] 2 (C sub(5)H sub(16)N sub(2) is N sup(1),N sup(1)-dimethylpropane-1,3-diaminium) (C sub(5)H sub(16)N sub(2))[MoS sub(4)] 3 (C sub(5)H sub(16)N sub(2) is N sup(1),N sup(3)-dimethylpropane-1,3-diaminium) (C sub(6)H sub(20)N sub(4))[MoS sub(4)] 4 (C sub(6)H sub(20)N sub(4) is 2-amino-N-{2-[(2-ammonioethyl)amino]ethyl}ethanaminium and (C sub(5)H sub(14)N sub(2))[MoS sub(4)] . 1/2 H sub(2)O 5 (C sub(5)H sub(14)N sub(2) is 1-methylpiperazine-1,4-diium) are reported. The charge balancing cations in 1-3 are protonated methyl substituted propanamines, while the dications of 4 and 5 are derived from a tetraamine and a cyclic diamine respectively. The crystal structures of 1 to 5 consist of an unique tetrahedral [MoS sub(4)] sup(2-) dianion charge balanced by a crystallographically independent organic dication for all compounds excepting 1 which contains a pair of unique (2-methylpropan-2-aminium) monocations. Although all the compounds are crystallized from aqueous solutions, 1 to 4 are anhydrous while 5 is a hemihydrate. In the crystal structures, the organic cations and the tetrasulfidomolybdate dianions are interlinked with the aid of several N-H...S and C-H...S hydrogen bonding interactions. In addition to N-H...S and C-H...S hydrogen bonds, compound 5 exhibits N-H...O and O-H...O hydrogen bonding interactions involving the H sub(2)O molecule, which interlinks pairs of anions with pairs of cations. Hirshfeld surface analyses were performed which reveal distortion of the [MoS sub(4)] sup(2-) tetrahedra, extensive S...H interactions between the anions and cations and also H...H contacts between the cations. A comparative study of the structural chemistry of thirty-eight tetrasulfidomolybdates is described.