A new family of three-legged piano stool structured organometallic compounds containing the fragment η 5 -cyclopentadienyl-ruthenium(II)/iron(II) has been synthesized to evaluate the existence of electronic metal to ligand charge transfer upon coordination of the novel benzodithiophene ligands (BDT), benzo[1,2-b;4,3-b′]dithiophen-2-carbonitrile (L1) and benzo[1,2-b;4,3-b′]dithiophen-2′nitro-2-carbonitrile (L2). All the compounds were characterized by 1 H, 13 C, 31 P NMR, IR and UV–Vis. spectroscopies and their electrochemistry studied by cyclic voltammetry. The X-ray structures of [Ru(η 5 -C 5 H 5 )(PPh 3 ) 2 (NCC 10 H 5 S 2 )][PF 6 ] (1Ru), [Ru(η 5 -C 5 H 5 )(PPh 3 ) 2 (NCC 10 H 5 S 2 )][CF 3 SO 3 ] (1′Ru), [Ru(η 5 -C 5 H 5 )(DPPE)(NCC 10 H 5 S 2 )][PF 6 ] 2Ru and [Fe(η 5 -C 5 H 5 )(DPPE)(NCC 10 H 5 S 2 )][PF 6 ] (2Fe) were determined by X-ray diffraction showing centric crystallization on groups P1¯ and P2 1 /n, respectively.Quadratic hyperpolarizabilities (β) of some of the complexes (2Fe, 2Ru and 3Fe) have been determined by hyper-Rayleigh scattering (HRS) measurements at a fundamental wavelength of 1500nm, to minimize the probability of fluorescence due to two-photon absorption and to reduce the effect of resonance enhancement, in order to estimate static β values.