32626-58-7Relevant academic research and scientific papers
Metal-exchange reaction on cationic polyiron μ3-η3-(C,C,O)-ketene and μ-η2-(C,O)-enolate complexes
Akita, Munetaka,Kawahara, Takashi,Terada, Masako,Kakinuma, Noboru,Moro-oka, Yoshihiko
, p. 687 - 693 (2008/10/08)
Cationic triiron μ3-η3-(C,C,O)-ketene complexes, [FP-CH2(C=O→FP+)-FP]BF4-, and diiron μ-η2-(C,O)-enolate complexes, [FP-CH2(C=O→FP+)R]BF4- [FP = (η5-C5R′5)Fe(CO)2, C6R′5 = C5H6 (Cp), C5H4Me (Cp′), C5Me5 (Cp*); Fp = CpFe(CO)2, Fp′ = Cp′Fe(CO)2, Fp* = Cp*Fe(CO)2; R = H, OMe, Ph, p-C6H4OMe], are prepared by the reactions of μ-η2-(C,C)-ketene complexes, FP-CH2CO-FP, and η1-(C)-enolate complexes, FP-CH2COR, with labile iron cations, [FP+(THF)]BF4-, respectively. Experiments employing Fp, Fp′, and Fp* as labeling agents reveal that the two iron centers bonded to the methylene terminus and the acyl oxygen atom exchange with each other via an intramolecular process. The rate of metal exchange increases as the alkyl substituents become electron donating. The equilibrium shifts to the side in which the methylene carbon is bonded to the FP group containing a less substituted cyclopentadienyl ring.
CHEMISCHE UND SPEKTROSKOPISCHE UNTERSUCHUNGEN AN KOMPLEX-KATIONEN DES TYPS (+). EIN BEITRAG ZUR DISKUSSION DER KOORDINATIONSEIGENSCHAFTEN VON PHOSPHANCHALKOGENIDEN UND DEREN HOEHEREN HOMOLOGEN
Kuhn, Norbert,Schumann, Hans
, p. 181 - 194 (2007/10/02)
The cations (+) are prepared from (+) and R3EX (R = CH3, i-C3H7, t-C4H9, C6H5, N(CH3)2; E = P, As, Sb; X = S, Se).NMR data indicate the ligands to be strong donors of the ylide type R3E(+)-X(-) in the coordinated state.On the other hand, the relative donor strength E = P>Sb>As may be interpreted as a result of (XE)Π bonding.
Preparative and reaction chemistry of the bimetallic μ-formate and μ-acetate complexes [(η-C5H5)(CO)2Fe]2O 2CR+PF6-
Tso, Chung C.,Cutler, Alan R.
, p. 1242 - 1247 (2008/10/08)
Unidentate η1-O Fp-O2CR and bimetallic μ-(η1-O,O′) Fp2(O2CR)+PF6- carboxylate complexes (R = H. CH3) have been synthesized and characterized [Fp = (η5-C5H5)(CO)2Fe]. Even though only a formate or acetate ligand bridges the Fp centers, these Fp2 μ-carboxylate salts do not dissociate in even polar solvents. Nucleophilic hydride donors and other nucleophiles (I-, PPh3) cleave these bimetallic salts via direct displacement at an iron center. No evidence was found, using labeling studies, for hydride addition to the μ-(η1-O,O′)-formate bridge and transience of a μ-(η1-O,O′)-methylenedioxy ligand, Fp-OCH2O-Fp.
Reactivity and conformation of a phosphine-substituted dihalocarbene complex. X-ray crystal structures of [(η5-C5H5)Fe(CO)(PPh3)(CF 2)][BF4] and [(η5-C5H5)Fe(CO)2(CCl 2)][BCl4]
Crespi, Ann M.,Shriver, Duward F.
, p. 1830 - 1835 (2008/10/08)
The difluorocarbene complex [CpFe(CO)(PPh3)(CF2)][BF4] (1) was prepared by halide abstraction from CpFe(CO)(PPh3)(CF3) using BF3. The structures of this compound and [CpFe(CO)2(CCl2)][BCl4], 2, determined by single-crystal X-ray diffraction, show the effect of ligand asymmetry on the dihalocarbene orientation. For 1 the plane of the CF2 ligand is tilted 18° away from coplanarity with the CO. Complex 2 adopts a vertical conformation with the plane of the CCl2 ligand bisecting the OC-Fe-CO angle. The orientations of CX2 in 1 and 2 agree with the conformations predicted by the MO treatment of Hoffmann and co-workers; however, low-temperature NMR measurements of 1 indicate that the CF2 group is rapidly rotating in solution, so the energy barrier between the various conformers is low. The reaction of CpFe(CO)(PPh3)(CF3) with BCl3 at low temperatures was followed by low temperature NMR, which indicates the successive formation of CF2, CFCl, and CCl2 complexes. These results substantiate a previously postulated mechanism for halide exchange. Crystal data for 1: space group, monoclinic, P21/c; a = 9.035 (3) A?, b = 24.390 (11) A?, c = 10.745 (5) A?, β = 102.20 (3)°; Z = 4. Crystal data for 2: space group, monoclinic, P21/c; a = 12.238 (4) A?, b = 9.444 (4) A?, c = 13.440 (4) A?, β = 113.55 (3)°; Z = 4.
REACTIVITIES OF LEWIS ACID ADDUCTS OF η5-C5H5(FeCO)2Y (Y=SPh, SO2Ph, AND PPh2) WITH NUCLEOPHILES
Weers, Jerry J.,Eyman, Darrell P.
, p. 47 - 55 (2007/10/02)
Complexes of the type CpFe(CO)2Y (Cp=η5-C5H5, Y=SPh(I), Y=PPh2 (II), Y=SO2Ph (III) and Cp'Fe(CO)2SPh (Cp'=η5-C5(CH3)5 (IV)), form adducts with the Lewis acids AlMe3, AlMe2Cl or AlBr3.All of the Lewis acid adducts of I react with one
