An unusual werner type clathrate of Mn(II) benzoate involving energetically significant weak C[sbnd]H⋯C contacts: A combined experimental and theoretical study.

Abstract A new Werner type manganese(II) clatharate [Mn(Bz) 2 (H 2 O) 4 ]∙(4–CNpy)∙2H 2 O (1), where Bz = benzoate and 4–CNpy = 4–cyanopyridine, has been synthesized at room temperature and characterized by X-ray crystal structure analysis, FT-IR, electronic spectrum and TGA. The crystal structure of cocrystal hydrate of 1 involves a discrete host monomer with enclathrated water and 4-CNpy molecules. Crystallographic studies on the compound 1 reveal that enclathration of guest water molecules in the Mn(II) host units results in a supramolecular tetramer in the crystal structure of 1 involving weak C H⋯C contacts. The geometry of the supramolecular host tetramer with the guest 4–CNpy molecules has been fully optimized using the crystallographic coordinates and the computational results suggest that the observed C H⋯C interactions are energetically quite significant. It is observed that both electrostatics as well as dispersion interactions are the most dominant contributors towards the stabilization of the C H⋯C interaction. Highlights • A new unusual Werner type clatharate of Mn(II) has been reported. • Mn(II) host units results in a supramolecular tetramer involving weak C H⋯C contacts. • The observed C H⋯C contacts are energetically quite significant. • Both electrostatics and dispersion interactions contribute towards stabilization of the C H⋯C interaction. [ABSTRACT FROM AUTHOR]