Deca-chloro-cyclo-penta-silanes coordinated by pairs of chloride anions, with different cations, but the same solvent mol-ecules.

We have determined the crystal structures of two deca-chloro-cyclo-penta-silanes, namely bis-(tetra-n-butyl-ammonium) dichloride deca-chloro-cyclo-penta-silane di-chloro-methane disolvate, 2C16H36N+·2Cl-·Si5Cl10·2CH2Cl2, (I), and bis-(tetra-ethyl-ammonium) dichloride deca-chloro-cyclo-penta-silane di-chloro-methane disolvate, 2C8H20N+·2Cl-·Si5Cl10·2CH2Cl2, (II), both of which crystallize with discrete cations, anions, and solvent mol-ecules. In (I), the complete deca-chloro-cyclo-penta-silane ring is generated by a crystallographic twofold rotation axis. In (II), one cation is located on a general position and the other two are disordered about centres of inversion. These are the first structures featuring the structural motif of a five-membered cyclo-penta-silane ring coordinated from both sides by a chloride ion. The extended structures of (I) and (II) feature numerous C-H⋯Cl inter-actions. In (II), the N atoms are located on centres of inversion and as a result, the ethyl-ene chains are disordered over equally occupied orientations.