Synthesis and X-ray structural characterization of three complexes of type cis-[M(dafone)2(NCS)2] (M = Co(II), 1; Ni(II), 2; Zn(II), 3; dafone = 4,5-diazafluoren-9-one) and a polymer cis-[Cd(dafone)(NCS)2]$_n$ (4) have been reported. Each of the four complexes is crystallized in orthorhombic crystal system. Structural study reveals that each metal(II) centre in the four complexes adopts distorted octahedral geometry with MN6 chromophore in 1-3 and MN4S2 chromophore in 4. The room temperature steady-state fluorescent intensity of dafone in dimethyl formamide at 402 nm is found to be quenched in these reported dafone complexes (1-4).
