157261-83-1Relevant academic research and scientific papers
Half-sandwich halide, alkyl, hydride, and related complexes of iron containing the bulky diphosphine 1,2-bis(diisopropylphosphino)ethane. Crystal structure of [FeH2(C5Me5)(dippe)][BPh4]
Jiménez-Tenorio, Manuel,Puerta, M. Carmen,Valerga, Pedro
, p. 3330 - 3337 (1994)
The four-coordinate iron phosphine complex [FeCl2(dippe)] (dippe = 1,2-bis(diisopropylphosphino)ethane) reacts with LiC5H5 or LiC5Me5 in thf, yielding the corresponding half-sandwich derivatives [FeCl(C5H5)(dippe)] (1) or [FeCl(C5Me5)(dippe)] (2), respectively. These complexes react with Grignard reagents RMgCl to give [FeR(C5H5)(dippe)] (R = Me (3) or CH2SiMe3 (4)) or [FeR(C5Me5)(dippe)] (R = Me (5)). If iPrMgCl is used, the monohydrides [FeH(C5H5)(dippe)] (6) and [FeH(C5Me5)(dippe)] (7) are obtained, presumably through a β-elimination reaction. These hydrides are also prepared by reaction between the corresponding chloro complexes and Li[HBEt3] in thf. The monohydrides 6 and 7 undergo a one-electron oxidation by reaction with [Fe(C5H5)2][PF6], yielding the 17-electron hydrides [FeH(C5H5)(dippe)]+ and [FeH(C5Me5)(dippe)]+, isolable as tetraphenylborate salts, [FeH(C5H5)(dippe)][BPh4] (8) and [FeH(C5Me5)(dippe)][BPh4] (9). The reaction of 1 or 2 with dihydrogen in methanol, followed by addition of Na[BPh4] yielded the dihydrides [FeH2(C5H5)(dippe)][BPh4] (10) and [FeH2(C5Me5)(dippe)][BPh4] (11), respectively. No equilibrium dihydride ? dihydrogen has been detected in these complexes, and therefore, they must be regarded as organoiron(IV) species. The crystal structure of 11 has been determined. Crystal data: monoclinic system, space group P21/n, cell parameters a = 14.277(4) A?, b = 21.388(6) A?, c = 14.619(6) A?, β = 101.07(3)°, and Z = 4. It suggests a transoid arrangement of hydride ligands consistent with the formulation as an iron(IV) dihydride. The vinylidene complexes [Fe=C=CHPh(C5H5)(dippe)][BPh4] (12) and [Fe=C=CHPh(C5Me5)(dippe)][BPh4] (13) were also prepared and characterized. Deprotonation of these vinylidene complexes yielded the alkynyl derivatives [Fe(C≡CPh)(C5H5)(dippe)] (14) and [Fe(C≡CPh)(C5H5)(dippe)] (15). All the compounds were characterized by NMR, IR, and microanalysis.
