Novel Br•••π(Chelate) Interaction in a 1D Coordination Polymer Revealing Aromaticity

A one-dimensional coordination polymer (1D CP) [Cu(nip)(4-brpy)(2)] (1) containing 16-member metal-ligand chelate ring exhibits unprecedented Br center dot center dot center dot pi(chelate) interaction. The nucleus-independent chemical shifts (NICS) calculation reveals that the chelate ring has aromaticity and strong interaction energy (-24.8 kcal/mol) which plays important role in molecular self-assembly in the crystal structure.