Supramolecular and theoretical perspectives of 2,2′:6′,2′′-terpyridine based Ni(ii) and Cu(ii) complexes: on the importance of C-HMIDLINE HORIZONTAL ELLIPSISCl and πMIDLINE HORIZONTAL ELLIPSISπ interactions

Two new complexes [Ni(L)Cl(H2O)(2)]Cl (complex 1) and [Cu(L)Cl-2] (complex 2) [L = 2,2 ':6 ',2 '' terpyridine] have been synthesized and characterized by single crystal X-ray analysis. The noncovalent interactions and supramolecular assemblies observed in the crystal packing of both complexes have been described focusing on non-traditional C-HMIDLINE HORIZONTAL ELLIPSISCl and 'traditional' O-HMIDLINE HORIZONTAL ELLIPSISCl hydrogen bonding interactions along with pi MIDLINE HORIZONTAL ELLIPSIS pi interactions. A DFT study has been carried out to analyze the pi MIDLINE HORIZONTAL ELLIPSIS pi, hydrogen bonding interactions with their rationalization and characterization using molecular electrostatic potential (MEP) surfaces and NCI plot computational tools.