Two new complexes with 6-methylnicotinic acid ligand: Synthesis, crystal structure and Hirshfeld surfaces

Two new complexes derived from 6-methylnicotinic acid: 1(Mn(C7H6NO2)2(H2O)2) and 2 ([Ni(C7H7NO2)2Cl2(H2O)2]·4H2O) have been synthesized and characterized. In complex 1, the MnII ion exhibits a distorted octahedral geometry and featured with 1D chain, while the NiII ion in complex 2 exhibits a regular octahedral geometry and featured with intricate 3D motif. We further compared the molecular Hirshfeld surface and fingerprint plot analysis of ligand 6-methylnicotinic acid in complexes 1 and 2 with the individual 6-methylnicotinic acid, for the purpose of investigating the influence of different metals on the intermolecular interaction around 6-methylnicotinic acid. Which revealed that the closest contacts of these two complexes were dominated by H⋯H, H⋯O, N⋯H, C–H⋯π and π⋯π (C–C) interactions, and the complexation with transition metals lead to the increase of C–H⋯π interactions while the decrease of H–H, N–H, and π⋯π interactions.