Self-assembly of DMF with chloromethane and their structures: a theoretical study

The stability of hydrogen-bonded complexes, DMF–H _n CCl_4−n (n = 1–3), has been investigated by several theoretical methods including the MP2 level of ab initio theory at various basis sets from 6-31+G* to 6-311++G**. Two stable configurations (respectively a and b) were obtained for each complex with no imaginary frequencies. The minimum energy structure of these complexes has also been analyzed by means of the atoms in molecule theory at MP2/6-311++G** level. It is found that C–H···O hydrogen bonding exists in these systems and that the intensity of HB interaction gradually increases with successive chlorination. Computed results indicate that these complexes automatically assemble into different stable configurations. For the complexes under consideration, their stabilities can be mainly ascribed to the intermolecular HB interaction. The present work is helpful to clearly understand the interaction mechanism of these complexes in theory.