15526-65-5Relevant academic research and scientific papers
Synthesis and characterization of a stable iron(II) hydride-thiolate complex: (PhS)Fe(H)(CO)2(P(OPh)3)2
Wander, Sheryl A.,Reibenspies, Joseph H.,Kim, Jang Sub,Darensbourg, Marcetta Y.
, p. 1421 - 1426 (2008/10/08)
The anionic, bis(phosphite)iron hydride complex [Et4N][HFe(CO)2(P(OPh)3)2] reacts with aryl disulfides to yield simple, monofunctional iron thiolate anions, (ArS)Fe(CO)2(P(OPh)3)2- (Ar = Ph, Tol). Methylation of the thiolates resulted in the formation of thioether species (ArSMe)Fe(CO)2(P(OPh)3)2, while protonation resulted in the formation of the stable thiolate-hydride complexes (ArS)Fe(H)(CO)2(P(OPh)3)2. cct-(PhS)Fe(H)(CO)2(P(OPh)3)2 was characterized by X-ray diffraction and found to be a regular octahedral complex in which the phosphite ligands are trans and the carbonyls cis, mutually trans to the hydride and benzenethiolate ligands. The hydride was located 1.41(7) ? from Fe with ∠H-Fe-S = 89(4)°. (PhS)Fe(H)(CO)2(P(OPh)3)2 crystallized in the monoclinic space group P21/n with a = 9.935(2) ?, b = 36.185(5) ?, c = 12.112(2) ?, β = 113.42(1)°, V = 3995.5(0) ?,3 and Z = 4. (PhS)Fe(H)(CO)2(P(OPh)3)2 was protonated to form the novel thiol-hydride complex (PhSH)Fe(H)(CO)2(P(OPh)3)2+.
Reactivity of Fe(CO)4(H)MPh3 (M = Si, Ge) and mechanism of substitution by two-electron-donor ligands: Implications for the mechanism of hydrosilylation of olefins catalyzed by Fe(CO)5
Bellachioma, Gianfranco,Cardaci, Giuseppe,Colomer, Ernest,Corriu, Robert J. P.,Vioux, André
, p. 519 - 525 (2008/10/08)
cis-Fe(CO)4(H)MPh3 (M = Si, Ge) complexes undergo carbonyl displacement with nucleophilic ligands (phosphines, phosphites) to give Fe(CO)3(H)(L)MPh3. With M = Si the geometry of these complexes depends on the nature of the solvent; in nucleophilic solvents the mer-OC-6-43 isomer is formed, while in nonnucleophilic solvents the mer-OC-6-23 isomer is obtained (the cis positions of H and Si are retained). These two isomers undergo concerted reductive elimination of silane with PPh3. The mer-OC-6-43 isomer reacts 183 ± 19 times faster than the mer-OC-6-23 isomer in toluene at 26.0°C, giving the same 16-electron intermediate; the calculated equilibrium constant for the interconversion of OC-6-43 and OC-6-23 is 823 ± 192 at 26.0°C in toluene. Owing to the strong acidity of Fe(CO)4(H)MPh3 (pKa estimated as 3CN) and of Fe(CO)3(H)(PPh3)MPh3 (pKa estimated as ≤8.94 in CH3CN), reaction with basic two-electron-donor ligands [P(alkyl)3, P(cycloalkyl)3, NR3] leads to the formation of the anionic trigonal-bipyramidal complexes [Fe(CO)4MPh3]- and [Fe(CO)3(L)MPh3]-. cis-Fe(CO)4(H)SiPh3 reacts with isoprene to give [Fe(CO)4SiPh3]2; this reaction is not observed with Fe(CO)3(H)(L)SiPh3. The versatile reactivity of these complexes sheds some light on the mechanism of hydrosilylation of olefins and conjugated dienes. Under thermal conditions previous coordination of the olefin to the metal in this reaction seems to be excluded.
Preparation and Spectroscopic Characterization of trans-Fe(CO)3L1L2 (L1, L2 = Phosphine or Phosphite)
Inoue, Hidenari,Kuroiwa, Takeshi,Shirai, Tsuneo,Fluck, Ekkehard
, p. 641 - 646 (2007/10/02)
The 57Fe Moessbauer spectra of mixed ligand complexes of the type trans-Fe(CO)3L1L2 (L1 = triphenylphosphine or triphenylphosphite and L2 = phosphine or phosphite) show a quadrupolesplitting doublet typical of the disubstituted iron carbonyls in trigonal bipyramidal symmetry.The inverse linear dependence of the isomer shifts on the CO stretching frequencies is interpreted on the basis of the strengthening triple-bond nature of the carbonyl ligands with increasing iron-to-phosphorus ?-back donation.A linear correlation, with a positive slope, between the isomer shifts and the quadrupole splittings has revealed that the phosphorus-to-iron ?-donation is offset by the iron-to-phosphorus ?-back donation.A corrlation between the coordination shifts and the isomer shifts demonstrates that the iron-to-phosphorus ?-back donation plays an important role in the Fe-P bond.The relatively large coupling constant of 2J(P,P) reflects a strong interaction between trans-phosphorus ligands through the P-Fe-P bond. - keywords: (Phosphine/Phosphite)tricarbonyliron, Moessbauer Spectra, IR Spectra, 31P NMR Spectra
Solution Structure and Dynamic Behaviour of two Isomers of (R = Me, Et, or Ph) Derivatives
Aime, Silvio,Botta, Mauro,Gambino, Olimpia,Gobetto, Roberto,Osella, Domenico
, p. 1277 - 1282 (2007/10/02)
The reaction between and P(OR)3 (R + Me, Et, or Ph) in the presence of the bimetallic catalyst affords two 1,2,3-trisubstituted isomers which rapidly interconvert at room temperature on the n.m.r. time-scale.The solution structures and dynamics have been elucidated for both isomers by means of variable-temperature 31P and 13C n.m.r. studies.In polar solvents the major isomer shows a -like structure whereas the minor one contains only terminally bonded CO groups.The observation of three equally intense carbonyl resonances in the low-temperature-limiting spectra (R = Me or Et) su pports a D3 structure for this isomer.The equilibration of axial CO ligands occurs readily as the temperature is increased; this rearrangement may be ascribed to the motion of the Fe3 triangle inside the polyhedral cloud of ligands or alternatively to an interconversion between a left-hand screw with a right-hand screw.
Substitutional reactivity of dodecacarbonyltrimetal complexes of iron and osmium
Shojaie, Abdolrasul,Atwood, Jim D.
, p. 187 - 190 (2008/10/08)
The kinetics of the substitution reactions of Fe3(CO)12 and Os3(CO)12 have been investigated for L = PPh3, PBu3, P(OPh)3, and P(OMe)3 in hydrocarbon solution. The substitution of the iron cluster leads to both substitution and fragmentation products with a very small dependence on the entering ligand, typical of a CO dissociative interchange mechanism. Substitution of Fe3(CO)11PPh3 leads only to fragmentation at a rate which is faster than substitution on Fe3(CO)12. Substitution on Os3(CO)12 occurs in an entering ligand independent reaction to Os3(CO)9L3. The reactivities of these clusters are compared to the ruthenium analogue and to the mononuclear complexes M(CO)5.
Metal Complexes with Tetrapyrrole Ligands XXXIII. Preparation of Azidochromium(III)-, Azidomanganese(III)-, and Azidoiron(III) Porphyrins and their Photolysis to Terminal or Bridged Nitridometal Porphyrins
Buchler, Johann Walter,Dreher, Christine
, p. 222 - 230 (2007/10/02)
Azidometal(III) porphyrins, e.g.M(TTP)N3 1 Aa - 1 Ca (M = Cr, Mn, Fe), are transformed into nitrido complexes on irradiation with ultraviolet light.Thus, Cr(III) or Mn(III) complexes, e.g.Cr(TTP)N3 or Mn(TTP)N3, yield Cr(V) and Mn(V) complexes with terminal nitride ligands, e.g.Cr(TTP)N (1 Ab) or Mn(TTP)N (1 Bb) with concomitant liberation of 1 mol of N2.However, the Fe(III) complex Fe(TTP)N3 produces the mixed-valence μ-nitrido-bis complex, 2N (1 Cg) and about 1.2 mol of N2 per mol of Fe.The azidometal(III) porphyrins are prepared from the corresponding hydroxo- or μ-oxo-metal(III) porphyrins and hydrazoic acid in benzene. - Key words: Chromium Porphyrins; Manganese Porphyrins; Nitridometal Complexes; Photolysis of Azido Complexes
Mechanism and equilibrium constants of the reaction between η4-heterodieneiron tricarbonyl complexes and group 5 ligands
Cardaci,Bellachioma
, p. 3099 - 3104 (2007/10/12)
The complexes Fe(CO)3(η2-C6H4XCH=CHCHO)L (where L = CO, X = 4-NMe2, 4-OMe, 3-OMe, 4-Me, 4-Cl; L = SbPh3, X = 3-OMe, 4-Cl) and Fe(CO)2(η4-C6H4XCH=CHCHO)L (where L = CO, X = 4-NMe2, 4-OMe, 3-OMe, 4-Me, 4-Cl; L = PPh3, X = H, 4-Cl, 4-Me, 4-OMe, 3-OMe) have been prepared and characterized. The reaction between Fe(CO)3(η4-C6H4XCH=CHCHO) (where X = H, 3-OMe, 4-Cl) and SbPh3 has been studied and the equilibrium constants and forward and reverse rate constants for this reaction have been measured. From the results obtained, it is concluded that the mechanism of this reaction proceeds via a dissociative equilibrium of the η4 complexes to η4 unsaturated complexes. The reaction between Fe(CO)3(η4-C6H4XCH=CHCHO) (where X = H, 4-NMe, 3-OMe, 4-OMe, 4-Me, 4-Cl) and PPh3 has also been studied. The kinetic law, the activation parameters, and the substituent effect indicate a reaction mode proceeding in two parallel directions. One of these is the same as that found for SbPh3 and the other corresponds to an associative process with the phosphine ligand. These results may be generalized to other diene complexes of iron tricarbonyl.
π Coordination of unsaturated bonds containing heteroatoms. II. Iron carbonyl complexes of azomethine analogs of 1,3-dienes. Preparation and nature of the coordination bondings
Otsuka, Sei,Yoshida,Nakamura
, p. 20 - 25 (2008/10/08)
The following mononuclear iron carbonyl complexes were prepared: (cinnamaldehydeanil)iron tricarbonyl (1), (crotonaldehyde-n-butylimine)iron tricarbonyl (2), (cinnamaldehydeanil)(triphenylphosphine)iron dicarbonyl (3), (diacetylanil)-iron tricarbonyl (4), and (diacetyl-n-butylimine)iron tricarbonyl (5). On the basis of the nmr spectra, it was inferred that the coordination of the enimine ligands in 1, 2, and 3 may be of π-1,3-diene type, analogous to butadiene iron tricarbonyl, while the α-diimine in 4 and 5 coordinates through its nitrogen lone pairs forming a chelate ring similar to the well-known α-diimine Fe(II) chelate complexes. Attempted preparations of (π-benzalazine)- or (π-acetalazine)iron carbonyl complexes were unsuccessful.
