Role of non-covalent interactions to dictate chiral selective self-assembly in Ni(II), Cu(II) and Cd(II) complexes of a racemic 1,2-dihydroquinazolinone ligand

Managing chirality at supramolecular level is an important aspect in crystal packing of chiral organic and organometallic molecules. Herein molecular structure of Ni(II), Cu(II) and Cd(II) complexes of a racemic 1,2-dihydroquinazolin-4(1H)-one ligand is described. The Cd(II) complexes exhibit intriguing structural features viz. capped octahedral geometry with seven coordination, and the presence of bridging as well as end-on azido ligand coordination to one metal center. Homo/heterochiral self-assembly in the complexes is dictated by strong N-H center dot center dot center dot N, N-H center dot center dot center dot O, N-H center dot center dot center dot Cl hydrogen bonds as well as non-classical C-H center dot center dot center dot O, C-H center dot center dot center dot N, N-H center dot center dot center dot pi hydrogen bonds and parallel displaced pi center dot center dot center dot pi stacking interaction. Chiral self-recognition or self-discrimination process in the crystal packing is governed by the nature and strength of the participating non-covalent interactions.