Insight into the role of pseudo-halides as multiple hydrogen bond acceptors in the formation of supramolecular 1D assembly of di and trinuclear zinc complexes

Abstract

In this manuscript we report the synthesis of two new zinc(II) complexes, [(DMSO)2 ZnL1Zn(NCS)2] (1), and [{(N3)ZnL2}2Zn(DMSO)2] (2) that were characterized by elemental and spectral analyses {H2L1 is 2,2-dimethyl-1,3-propanediylbis(iminomethylene)bis(phenol), and H2L2 is 1,2-propanediylbis(iminomethylene)bis(4-chlorophenol)}. The structures have been confirmed by single crystal X-ray diffraction analysis. Both complexes form 1D supramoelcular assemblies where the pseudohalides act as multiple H-bond acceptors (CH•••S,N and NH•••S,N). These assemblies have been analyzed theoretically using DFT calculations, and the energy associated to each contact has been estimated using the quantum theory of atoms-in-molecules. The importance of long-range van der Waals interactions is emphasized. This manuscript, where two new complexes are synthesized and the H-bonding contacts individually estimated, is expected to attract the attention not only of synthetic inorganic chemists, but also theoreticians and chemists working in crystal engineering and supramolecular chemistry.