Abstract
Intermolecular interactions play a vital role in crystal structures. Therefore, we conducted a topological study, using Hirshfeld surfaces and atom in molecules (AIM) analysis, to decompose and analyze, respectively, the different intermolecular interactions in six hydrazone-diacetyl platinum(II) complexes. Using AIM and natural bond orbital (NBO) analyses, we determined the type, nature, and strength of the interactions. All the studied complexes contain C-H center dot center dot center dot O interactions, and the presence of bond critical points along the intermolecular paths underlines their significance. The electron densities (rho(r)) at the bond critical points (0.0031-0.0156 e/a(0)(3)) fall within the typical range for H-bonding interactions. Also, the positive values of the Laplacian of the electron density (del(2)rho(r)) revealed the depletion of electronic charge on the interatomic path, another characteristic feature of closed-shell interactions. The ratios of the absolute potential energy density to the kinetic energy density (vertical bar V(r)vertical bar/G(r)) and rho(r) are highest for the O2 center dot center dot center dot H15-N3 interaction in [Pt(COMe)(2)(2-pyCMe=NNH2)] (1); hence, this interaction has the highest covalent character of all the O center dot center dot center dot H intermolecular interactions. Interestingly, in [Pt(COMe)(2)(H2NN=CMe-CMe=NNH2)] (3), there are significant N-H center dot center dot center dot Pt interactions. Using the NBO method, the second-order interaction energies, E(2), of these interactions range from 3.894 to 4.061 kJ/mol. Furthermore, the hybrid Pt orbitals involved in these interactions are comprised of d(xy), d(xz), and s atomic orbitals.