Studies of Fe2(CO)9 Formation in the Thermolysis of Fe(CO)5 Using Ab Initio Calculations of Fe(CO)5 and Fe(CO)4

Ab initio calculations using the GAMESS program package in the atomic basis TZV (Fe: (14s, 11p, 6d)/[10s, 8p, 3d]; C, O: (11s, 6p)/[5s, 3p]) were performed with account taken of the correlation with the second-order Möller–Plesset (MP2) perturbation theory to predict a new conformer Fe(CO)₄ (with D _4h symmetry). This conformer has a square planar configuration in the ground singlet electronic state and is a mild electrophile produced by dissociation of Fe(CO)₅ along the axial Fe–C bond. The process of nucleation of iron nanoparticles Fe(CO)₅ + Fe(CO)₄ Fe₂(CO)₉ is supposed to occur in two stages. The first stage is an orbital-controlled reaction which should be monitored as an increase in medium polarity and temperature. It should proceed with participation of only one of the stable conformers of the nucleophile Fe(CO)₅, namely, a mild conformer with square-pyramidal structure (C _4v ) rather than a hard but energetically more advantageous conformer with trigonal–bipyramidal structure (D _3h ). The structure of a prereaction complex was discussed.     

Unraveling the photochemistry of Fe(CO)5 in solution: observation of Fe(CO)3 and the conversion between 3Fe(CO)4 and 1Fe(CO)4(Solvent)

The photochemistry of Fe(CO)5 (5) has been studied in heptane, supercritical (sc) Ar, scXe, and scCH4 using time-resolved infrared spectroscopy (TRIR). 3Fe(CO)4 ((3)4) and Fe(CO)3(solvent) (3) are formed as primary photoproducts within the first few picoseconds. Complex 3 is formed via a single-photon process. In heptane, scCH4, and scXe, (3)4 decays to form (1)4 x L (L = heptane, CH4, or Xe) as well as reacting with 5 to form Fe2(CO)9. In heptane, 3 reacts with CO to form (1)4 x L. The conversion of (3)4 to (1)4 x L has been monitored directly for the first time (L = heptane, kobs = 7.8(+/- 0.3) x 10(7) s(-1); scCH4, 5(+/- 1) x 10(6) s(-1); scXe, 2.1(+/- 0.1) x 10(7) s(-1)). In scAr, (3)4 and 3 react with CO to form 5 and (3)4, respectively. We have determined the rate constant (kCO = 1.2 x 10(7) dm3 mol(-1) s(-1)) for the reaction of (3)4 with CO in scAr, and this is very similar to the value obtained previously in the gas phase. Doping the scAr with either Xe or CH4 resulted in (3)4 reacting with Xe or CH4 to form (1)4 x Xe or (1)4 x CH4. The relative yield, [(3)4]:[3] decreases in the order heptane > scXe > scCH4 > scAr, and pressure-dependent measurements in scAr and scCH4 indicate an influence of the solvent density on this ratio.     

Fluxional behavior of (CO)4Fe(u-AsMe2)Mo(CO)2(C5H5)

The ¹H and ¹³C NMR spectra of the heterobimetallic compound (CO)₄Fe(μ-AsMe₂)Mo(CO)₂(C₅H₅) reveal three different fluxional processes.     

Ag[Fe(CO)5]2+: A Bare Silver Complex with Fe(CO)5 as a Ligand

Attempts to prepare Fe(CO)₅⁺ from Ag[Al(OR^F)₄] (R^F=C(CF₃)₃) and Fe(CO)₅ in CH₂Cl₂ yielded the first complex of a neutral metal carbonyl bound to a simple metal cation. The Ag[Fe(CO)₅]₂⁺ cation consists of two Fe(CO)₅ molecules coordinating Ag⁺ in an almost linear fashion. The ν(CO) modes are blue‐shifted compared to Fe(CO)₅, with one band above 2143 cm^?1 indicating that back‐bonding is heavily decreased in the Ag[Fe(CO)₅]₂⁺ cation.     

(n-C5H5) (CO)2W{n3-C5H5[(n-C5H4)2Fe]} - ein neuer Fe und N enthaltender Zweikernkomplex

(η-C₅H₅)(CO)₂W[(η³-C₅H₅)(C₅H₅)₂], I, containing two tilted five-membered rings, is converted into the bridged ferrocene derivative (η-C₅H₅)(CO)₂W{(η³-C₅H₅)}[(η-C₅ H₄)₂Fe]} II by successive reaction with Na and FeCl₂.     

Oxin (8-Hydroxychinolin) und seine Derivate

Ohne Zusammenfassung     

Synthesis of a transition metal-dithionite complex, (η5-C5H5)(CO)2FeS(O)2S(O)2Fe(CO)2(η5-C5H5)

The reaction of Na[η⁵-C₅H₅Fe(CO)₂] with large excess of SO₂ in THF at ?78°C followed by warming to room temperature affords an iron—dithionite complex, (η⁵-C₅H₅)(CO)₂FeS(O)₂S(O)₂Fe(CO)₂(η⁵-C₅H₅).     

Synthesen und Kristallstrukturen von [(t-Bu4Sb4)Fe(CO)4], [(t-Bu4Sb4)Mo(CO)5] und [(t-Bu3Sb4)Mo(η5-C5Me5)(CO)3]

Syntheses and Crystal Structures of [( t -Bu₄Sb₄)Fe(CO)₄], [( t -Bu₄Sb₄)Mo(CO)₅], and [( t -Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] t-Bu₄Sb₄ reacts with Fe₂(CO)₉ to form [(t-Bu₄Sb₄)Fe(CO)₄] ( 1 ). [(t-Bu₄Sb₄)Mo(CO)₅] ( 2 ) is formed from (thf)Mo(CO)₅ and t-Bu₄Sb₄. [(t-Bu₃Sb₄)Mo(η⁵-C₅Me₅)(CO)₃] ( 3 ) is a product of the reaction of t-Bu₄Sb₄ with [(η⁵-C₅Me₅)Mo(CO)₃]₂. The crystal structures of 1–3 are reported.     

Improved preparation of h5-C5H5 Fe(CO)2(h1-alkyl) complexes from [h5-C5H5Fe(CO)2(h2-alkene)]+BF4−

Sodium cyanoborohydride has been found to be very effective for the conversion of [(h⁵-C₅H₅)Fe(CO)₂(h²-alkene)]⁺BF₄^? complexes to the corresponding h¹-alkyl derivatives.     

Photochemical reactions of (CO)2 (PPh3)MnC5H4Fe(CO)2C5H5 and (CO)2(PPh3)MnC5H4COFe(CO)2C5H5 with PPh3

Conclusions The photochemical reactions of (CO)₂(PPh₃)MnC₅H₄Fe(CO)₂C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)₂C₅H₅ with PPh₃ gave the products of replacing the CO on the Fe atom by PPh₃: respectively (CO)₂(PPh₃)MnC₅H₄Fe (CO)(PPh₃)C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)(PPh₃)C₅H₅.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2813–2815, December, 1977.     

Cyclopropene als komplexliganden. Cyclopropenthionkomplexe mit den gruppen Cr(CO)5 und (C5H5)Mn(CO)2

Diphenylcyclopropenethione and dithienylcyclopropenethione react with (acetonitrile)₃Cr(CO)₃ under mild conditions with formation of (C₃Ph₂S)Cr(CO)₅ and [C₃(C₄H₃S)₂S]Cr(CO)₅, respectively. Using (η⁵-C₅H₅)(THF)Mn(CO)₂ and diphenylcyclopropenethione a different type of complex with the stoichiometry (C₃Ph₂S)₂Mn(C₅H₅)(CO)₂ is obtained. A structure with a ligand containing two S bridges is proposed.     

Stereoselective addition of CCl4 to 2S-methoxycarbonylN-(trans-cinnamoyl)pyrrolidine in the presence of Fe(CO)5 or Fe2(CO)9

Addition of CCl₄ to 2S-methoxycarbonyl-N-(trans-cinnamoyl)pyrrolidine in the presence of Fe(CO)₅ or Fe₂(CO)₉ results in predominant formation of one of four possible optical isomers of the adduct PhCHClCH(CCl₃)C(O)R (R=2S-methoxycarbonylpyrrolidyl).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1390–1392, July, 1995.     

Synthese und Kristallstruktur von (C5H5)Mo(CO)3(AuPPh3) und [(C5H5)Mo(CO)2(AuPPh3)4]PF6

Synthesis and Crystal Structure of (C₅H₅)Mo(CO)₃(AuPPh₃) and [(C₅H₅)Mo(CO)₂(AuPPh₃)₄]PF₆ CpMo(CO)₃(AuPPh₃) is obtained by the reaction of Li[CpMo(CO)₃] with Ph₃PAuCl at ?95°C in CH₂Cl₂. It crystallizes in the monoclinic space group C2/c with a = 2625.1(7), b = 883.2(1), c = 2328.4(7) pm, β = 116.39(1)° und Z = 8. In the complex the AuPPh₃ group is coordinated to the CpMo(CO)₃ fragment with a Au? Mo bond of 271,0 pm. The Mo atom thus achieves a square pyramidal coordination with the center of the Cp ring in apical position. CpMo(CO)₃(AuPPh₃) reacts under uv irradiation with an excess of Ph₃PAuN₃ to afford the cluster cation [CpMo(CO)₂(AuPPh₃)₄]⁺. It crystallizes as [CpMo(CO)₂(AuPPh₃)₄]PF₆ · 2 CH₂Cl₂ in the orthorhombic space group P2₁2₁2₁ with a = 1553.9(1), b = 1793.8(2), c = 2809.8(7) pm und Z = 4. The five metal atoms form a trigonal bipyramidal cluster skeleton with the Mo atom in equatorial position. The Mo? Au distances range from 275.5 to 280.8 pm, and the Au? Au distances are between 281.2 and 285.6 pm.     

Synthese und Struktur von [Fe6(CO)12(TePh)12]

Synthesis and Structure of [Fe₆(CO)₁₂(TePh)₁₂] The reaction of [Fe(CO)₄(HgCl)₂] with PhTeSiMe₃ leads to the formation of red needles. [Fe₆(CO)₁₂(TePh)₁₂] was characterised by single crystal x‐ray structure analysis. In this compound each iron atom is coordinated octahedrally by four μ₂‐TePh groups and two terminal CO groups. The iron atoms form a six membered planar ring.