febr2 has reacted with an equivalent of mnt2- (mnt = cis-1,2-dicyanoethylene-1,2-dithiolate) and the α-diimine l (l = 1,10'-phenantroline, 2,2'-bipyridine) in thf solution, and followed by adding of t-butyl-isocyanide to give [fe(mnt)(l)(t-bunc)2] neutral compound. the products were characterized by infrared, uv-visible and m？ssbauer spectroscopy, besides thermogravimetric and conductivity data. the geometry in the equilibrium was calculated by the density functional theory and the electronic spectrum by the time-dependent. the experimental and theoretical results in good agreement have defined an octahedral geometry with two isocyanide neighbours. the π→π* intraligand electronic transition was not observed for cis-isomers in the near-ir spectral region.