Novel ‘main-part’ isostructuralism in metal complexes with 1-methylimidazole: crystal structures, energy calculations and magnetic properties

PIRO, OSCAR E.; BEN ALTABEF, AIDA; GIL, DIEGO M.; DI SANTO, ALEJANDRO; GONZÁLEZ, MARLENE; FRONTERA, ANTONIO; PÉREZ, HIRAM; ECHEVERRÍA, GUSTAVO A.; GOMILA, ROSA M.

DALTON TRANSACTIONS

ROYAL SOC CHEMISTRY

Año: 2021 vol. 50 p. 17029 - 17040

1477-9226

Two new transition metal complexes with 1-methylimidazole (1-MeIm) and azide as ligands, namely, [Co(1-MeIm)4(N3)2] (1) and [Ni(1-MeIm)4(N3)2] (2), have been synthesized and characterized by IR, Raman, UV-Vis and XPS spectroscopy. Their crystal structures were solved by single-crystal X-ray diffraction. The supramolecular self-assembly of the two complexes is governed by non-classical C?H⋯N hydrogen bonds and C?H⋯π interactions. Lattice energies and intermolecular interaction energies for various molecular pairs are quantified using the PIXEL method. DFT computational studies to assess the binding energy through modern tools like non-covalent interaction (NCI plots) analysis and reduced density gradient (RDG) analysis have also been carried out. A detailed analysis of geometric descriptors revealed the existence of quasi-isostructural pairs or ?main-part? isostructuralism in a series formed by 1, 2, and a related cadmium complex, being more evident in the 1/2 pair. DFT studies using theoretical models have been used to disclose the relative importance of the H-bond and C?H⋯π noncovalent interactions. Magnetic measurements for compound 1 show weak ferrimagnetic coupling between adjacent M(II) centers, mediated by H-bonding and C?H⋯π non-covalent interactions.