Crystal structures and hydrogen-bonding analysis of a series of solvated ammonium salts of molybdenum(II) chloride clusters.

Charge-assisted hydrogen bonding plays a significant role in the crystal structures of solvates of ionic com­pounds, especially when the cation or cations are primary ammonium salts. We report the crystal structures of four ammonium salts of molybdenum halide cluster solvates where we observe significant hydrogen bonding between the solvent molecules and cations. The crystal structures of bis(anilinium) octa-μ₃-chlorido-hexa­chlorido-octa­hedro-hexa­molybdate N,N-di­­methyl­formamide tetra­solvate, (C₆H₈N)₂[Mo₆Cl₈Cl₆]·4C₃H₇NO, (I), p-phenyl­enedi­ammonium octa-μ₃-chlorido-hexa­chlorido-octa­hedro-hexa­mol­yb­date N,N-di­methyl­formamide hexa­solvate, (C₆H₁₀N₂)[Mo₆Cl₈Cl₆]·6C₃H₇NO, (II), N,N′-(1,4-phenyl­ene)bis­(propan-2-iminium) octa-μ₃-chlorido-hexa­chlo­rido-octa­hedro-hexa­molybdate acetone tris­olvate, (C₁₂H₁₈N₂)[Mo₆Cl₈Cl₆]·3C₃H₆O, (III), and 1,1′-dimethyl-4,4′-bipyridinium octa-μ₃-chlo­rido-hexa­chlorido-octa­hedro-hexa­molybdate N,N-di­methyl­formamide tetra­solvate, (C₁₂H₁₄N₂)[Mo₆Cl₈Cl₆]·4C₃H₇NO, (IV), are reported and described. In (I), the anilinium cations and N,N-di­methyl­formamide (DMF) solvent mol­ecules form a cyclic R₄²(8) hydrogen-bonded motif centered on a crystallographic inversion center with an additional DMF mol­ecule forming a D(2) inter­action. The p-phenyl­enedi­ammonium cation in (II) forms three D(2) inter­actions between the three N—H bonds and three independent N,N-di­methyl­formamide mol­ecules. The dication in (III) is a protonated Schiff base solvated by acetone mol­ecules. Compound (IV) contains a methyl viologen dication with N,N-di­methyl­formamide mol­ecules forming close contacts with both aromatic and methyl H atoms. [ABSTRACT FROM AUTHOR]