Synthesis, crystal structure, and fluorescence studies of (1-naphthyl)(pyridyl)urea metal complexes

Three supramolecular complexes, [ML2Cl2(MeOH)2] (M = Cu (1), Co (2) and Ni (3); L = N-(1-naphthyl)-N′-(3-pyridyl)urea) have been synthesized and characterized. X-ray single-crystal diffraction analyses revealed a 2D network for the isomorphous complexes 1, 2 and 3 formed by intermolecular N–H⋯Cl hydrogen bonding and π–π stacking interactions. The fluorescent properties of the complexes have been investigated. While complexes 2 and 3 showed a red-shifted fluorescence emission in the solid-state compared to L, complex 1 displayed a quenching of the fluorescence.