C-H•••π interactions in cocrystals of bis(trimethylsilyl)acetylene and diphenylacetylene with benzene

We present here the crystal structures of two acetylene derivatives cocrystallized with benzene, namely bis(trimethylsilyl) acetylene benzene solvate, C8H18Si2 center dot C6H6, (I), and diphenylacetylene benzene solvate, C14H10 center dot C6H6, (II). In (I), both molecules belong to the symmetry point group C-2h and are located about special positions with site symmetry 2/m. In (II), both molecules show crystallographic inversion symmetry. In both structures, there are C-H center dot center dot center dot pi contacts between aromatic H atoms and the pi-electrons of the triple bond. In addition to these, in (II) there are C-H center dot center dot center dot pi contacts between aromatic H atoms and the pi-electron cloud of the benzene molecules.