Crystal structure of [2-(diphenylphosphino)phenyliminoethyl]- ferrocene, Fe(C₅H₅)(C₂₅H₂₁NP)

Abstract

C 30 H 26 FeNP, monoclinic, P2 1 /n (no. 14), a =10.750(2) Å, b =9.077(2) Å, c =24.489(5) Å, b =90.85(3)°, V =2389.3 Å 3 , Z =4,R gt(F) =0.042, wRref(F 2 ) =0.113, T =293 K. Source of materialThe raw material 2-(diphenylphosphino)aniline was prepared by al iterature method [1], and acetylferrocene was commercially obtained. Acetylferrocene (1.14 g, 5.0 mmol), 5 Å molecular sieve (2.0 g) and 2-(diphenylphosphino)aniline (1.325 g, 5.0 . mmol) were suspended in dried toluene (20 cm 3 ). The reaction mixtures were refluxed at stirring for 5-6day. In order to control the progress of the condensation reaction the infrared spectra of the solutions were recorded. Daily addition of small quantities of the amine (0.2 g, 1mmol) and molecular sieve (4 Å) was needed to force the displacement of the equilibria. This procedure was repeated for 5-6day until the infrared spectra of the samples did not exhibit the band due to the asymmetrical stretching of the C=O group of the acetylferrocene [n(C=O) 1662 cm -1 ]. Then, the molecular sieves were removed by vacuum filtration and washed with ether until the liquid became colourless. The orange-red solution was concentrated on arotary evaporator, and the oil formed was treated with methylene dichloride (10 cm 3 ). Slow evaporation of the solvent afforded the red crystal of the title compound (1.950 g, yield 81 %). DiscussionFerrocene and its derivatives have attracted much attention for their potential applications as molecular sensors, magnetic and optical materials, and in homogeneous catalysis. Several studies on the Schiff base containing-ferrocene have been reported recently [2][3][4][5][6]. The title molecule is in a trans configuration of the benzene ring and the cyclopentadienyl ring in respect to the N=C11 bond; the dihedral angle between the planes C6-C10 and N/C13-C18 is 45(1)°.Inthe ferrocen group, the Fe-Cbond lengths are within the normal range [7]. The Fe1···Cg1 and Fe1···Cg2 distances are 1.629 Å and 1.634 Å,respectively, and the Cg1···Fe···Cg2 angle is 178.9°,where Cg1 and Cg2 are the centroids of the substituted and unsubstituted Cp rings, respectively. The two Cp rings are almost eclipsed, with adihedral angle of 1.4°,and the largest torsion angle C2···Cg1···Cg2···C9 is 6.1°.Inthe triphenylphosphine group, the Pa tom adopts as lightly distorted pyramidal coordination.