Theoretical investigation on the structure and thermodynamic properties of the 2,4-dinitroimidazole complex with methanol.

The structure and thermodynamic properties of the 2, 4-dinitroimidazole complex with methanol were investigated using the B3LYP and MP2(full) methods with the 6-31++G(2d,p) and 6-311++G(3df,2p) basis sets. Four types of hydrogen bonds [N-H⋯O, C-H⋯O, O-H⋯O (nitro oxygen) and O-H⋯π] were found. The hydrogen-bonded complex having the highest binding energy had a N-H⋯O hydrogen bond. Analyses of natural bond orbital (NBO) and atoms-in-molecules (AIM) revealed the nature of the intermolecular hydrogen-binding interaction. The changes in thermodynamic properties from monomers to complexes with temperatures ranging from 200.0 to 800.0 K were investigated using the statistical thermodynamic method. Hydrogen-bonded complexes of 2,4-dinitroimidazole with methanol are fostered by low temperatures.