Reduced band gap in [Pb sub(2)I sub(4)(datone) sub(2)] sub(n) Synthesis, properties and calculations

Phenanthroline derivative, 4,5-diazafluoren-9-one(dafone), was introduced into lead iodine hybrid to synthesize a new hybrid [Pb sub(2)I sub(4)(dafone) sub(2)] sub(n)( 1), in which each lead atom adopts a distorted octahedral coordination and presents a one-dimensional polymer by edge-sharing mode. Due to the presence of O acceptor in dafone, C-H[inline image]O hydrogen bonds can be observed and contribute to the formation of 2-D layer. Experimental and theoretical optical property investigation indicate that 1 possesses semiconductor property. Specially, DFT calculation suggests that 1 displays a reduced band gap (1.36 eV), which is assigned to a more dispersed LUMO band compared with [Pb sub(2)I sub(4)(phen) sub(2)] sub(n)and [Pb sub(2)I sub(4)(bipy) sub(2)] sub(n)