C–H⋯X (X = S, P) hydrogen bonding: The complexes of halothane with dimethyl sulfide and trimethylphosphine

The formation of C–H⋯S and C–H⋯P hydrogen bonded complexes of halothane, CHBrClCF3, with dimethyl sulfide(-d6) and trimethylphosphine(-d9) have been studied in solutions of liquid krypton using infrared and Raman spectroscopy. In the 1:1 complexes, the halothane CH stretching mode is found to be red-shifted by 43 cm−1 in the dimethyl sulfide complex, and by 63 cm−1 in the trimethylphosphine complex. The complexation enthalpies were derived and amount to −10.7(2) and −11.2(2) kJ mol−1 for the respective complexes. The experiments were supported by ab initio calculations and Monte Carlo simulations. The obtained data for the C–H⋯S and C–H⋯P hydrogen bonds is compared to that of corresponding C–H⋯O and C–H⋯N hydrogen bonds.