A new series of neutral nitrosyl(η4-tetraphenylcyclobutadiene)iron(0) complexes: crystal and molecular structure of (NN-diethyldithiocarbamato-SS′)nitrosyl(η4-tetraphenylcyclobutadiene)iron(0)

Abstract

Reactions of the cationic nitrosyl(η⁴-tetraphenylcyclobutadiene)iron(0) complexes [Fe(NO)(CO)₂(η⁴-C₄Ph₄)]⁺(1) and [Fe(NO)(CO)(PPh₃)(η⁴-C₄Ph₄)]⁺(2) with uni- and bi-dentate anionic nucleophiles have been investigated. Complex (2) reacts with Cl^– to give [FeCl(NO)(PPh₃)(η⁴-C₄Ph₄)](3). Reaction of (1) with X^–(X = Cl, NCO, NCS, NO₂, or N₃) yields polynuclear complexes [{FeX(NO)(η⁴-Ph₄C₄)}_n](5) where n is probably 2. With potentially chelating anions (1) yields the mononuclear complexes [FeZ(NO)(η⁴-C₄Ph₄)][Z = NO₃(6), pentane-2,4-dionate (7), or S₂CNEt₂(8)]. The structure of (8) has been established by an X-ray crystallographic analysis. Crystals are monoclinic, a= 11.383(2), b= 16.211 (3), c= 15.529(4)Å, β= 93.23(2)°, Z= 4, and space group P2₁/n. The structure was solved by the heavy-atom method and refined by full-matrix least-squares calculation to R= 0.027 and R′= 0.031 for 2 998 reflections with I > 3σ(I). The iron atom is co-ordinated to four carbon atoms of tetraphenylcyclobutadiene [Fe–C 2.061(2), 2.070(2), 2.034(2), and 2.065(2)Å], to the two S atoms of the dithiocarbamato-ligand [Fe–S 2.317(1) and 2.316(1)Å], and to the N atom of the nitrosyl ligand [Fe–N 1.649(3), N–O 1.167(3)Å]. The nitrosyl ligand is slightly bent [Fe–N–O 170.4(3)°].