Decomposition of Intermolecular Interactions in the Crystal Structure of Some Diacetyl Platinum(II) Complexes: Combined Hirshfeld, AIM, and NBO Analyses.

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. . .O interactions, and the presence of bond critical points along the intermolecular paths underlines their significance. The electron densities (ρ(r)) at the bond critical points (0.0031-0.0156 e/a0 3) fall within the typical range for H-bonding interactions. Also, the positive values of the Laplacian of the electron density (r2ρ(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 (V(r)/G(r)) and ρ(r) are highest for the O2. . . H15-N3 interaction in [Pt(COMe)2(2-pyCMe=NNH2)] (1); hence, this interaction has the highest covalent character of all the O. . .H intermolecular interactions. Interestingly, in [Pt(COMe)2(H2NN=CMe-CMe=NNH2)] (3), there are significant N-H. . . 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 dxy, dxz, and s atomic orbitals. [ABSTRACT FROM AUTHOR]