Synthesis and optical properties for crystals of a novel organic semiconductor [ Ni(Cl) 2{(Ph 2P) 2CHC(R 1R 2)NHNH 2}]A. M. Badr, A. A. EL-Amin and A. F. Al-HossainyEur. Phys. J. B, 53 4 (2006) 439-448DOI: https://doi.org/10.1140/epjb/e2006-00406-4