Chloride-chloroform clusters exhibiting weak hydrogen and halogen bondings are fully characterized in the solid state by X-ray diffraction

Two (1,3,5-triazapentadiene/ato)Pt II complexes, [1][(Cl) 2 ] and [2][(Cl) 2 ], were synthesized by the previously reported platinum-mediated nitrile-amidine coupling. Both complexes crystallize as mixed chloroform—ethanol solvate [1][(Cl) 2 (CHCl 3 ) 7 (EtOH) 2 ] and [2][(Cl) 2 (CHCl 3 ) 6 (EtOH) 2 ] from the reaction mixture by slow evaporation of the commercial chloroform (containing ca. 1% ofEtOH) taken as the solvent, while crystals of [2][(Cl) 2 (CHCl 3 ) 4 ] were obtained when distilled chloroform was employed. In the crystal structure of [1][(Cl) 2 (CHCl 3 ) 7 (EtOH) 2 ], [2][(Cl) 2 (CHCl 3 ) 6 (EtOH) 2 ], and [2][(Cl) 2 -(CHCl 3 ) 4 ] solvates, the Cl - ion interacts with [1] 2+ or [2] 2+ by means of hydrogen bonding and via one hydrogen bridge, thus forming stacked arrays. The negatively charged cluster ions [Cl - (CHCl 3 ) n ] (n = 2, 3) are stabilized via C-H···Cl - hydrogen bridges between the Cl - ion and CHCl 3 molecules. In [1][(Cl) 2 (CHCl 3 ) 7 (EtOH) 2 ], two chloroform clusters dimerize to the [Cl - (CHCl 3 ) 3 ) 2 species, where the halogen bonding between one Cl atom of CHCl 3 and Cl - anion was detected. The halogen bonding was studied by theoretical methods (B3LYP, MP2), including the bond energy, AIM, and NBO charge transfer analyzes.