Synthesis and crystal structures of two 1,3-di(alk­yloxy)-2-(methyl­sulfan­yl)imidazolium tetra­fluorido­borates

Two salts were prepared by methyl­ation of the respective imidazoline-2-thione at the sulfur atom, using Meerwein’s salt (tri­methyl­oxonium tetra­fluorido­borate) in CH(2)Cl(2). 1,3-Dimeth­oxy-2-(methyl­sulfan­yl)imidazolium tetra­fluorido­borate (1), C(6)H(11)N(2)O(2)S(+)·BF(4) (−), displays a syn conformation of its two meth­oxy groups relative to each other whereas the two benz­yloxy groups present in 1,3-dibenz­yloxy-2-(methyl­sulfan­yl)imidazolium tetra­fluorido­borate (2), C(18)H(19)N(2)O(2)S(+)·BF(4) (−), adopt an anti conformation. In the mol­ecules of 1 and 2, the methyl­sulfanyl group is rotated out of the plane of the respective heterocyclic ring. In both crystal structures, inter­molecular inter­actions are dominated by C—H⋯F—B contacts, leading to three-dimensional networks. The tetra­fluorido­borate counter-ion of 2 is disordered over three orientations (occupancy ratio 0.42:0.34:0.24), which are related by rotation about one of the B—F bonds.