Alla B. Antonova

A novel methodology for the synthesis of complexes containing long carbon chains linking metal centres: molecular structures of {Ru(dppe)Cp*}2(μ-C14) and {Co3(μ-dppm)(CO)7}2(μ3:μ3-C16)

Elimination of AuX(PR3)(X = halogen, R = Ph, tol) occurs readily in reactions between compounds containing C(sp)- or C(sp2)-X bonds and alkynyl or polyynyl gold(I) complexes; this reaction has been applied to the syntheses of complexes containing a variety of metal centres linked by C(n) chains (n up to 16).

Chemistry of vinylidene complexes. III. Binuclear manganese-platinum complexes with bridgingphenylvinylidene ligand

Abstract The vinylidene manganese complexes Cp(CO) 2 MnCCHPh reacts with (η 2 - trans -PhCHCHPh)Pt(PPh 3 ) 2 and PtL 4 (LPPh 3 , P(OEt) 3 orP(OPh) 3 ) to afford the heteronuclear dimetal compounds of the type Cp(CO) 2 MnPt(μ-CCHPh)L 2 , the first platinum-containing complexes with phenylvinylidene ligand. The structures of the novel compounds are suggested on the basis of the IR, 1 H, 13 C and 31 P NMR spectral data.

Chemistry of vinylidene complexes. XIII. The reaction between Cp(CO)2MnPt(μ-CCHPh)(η2-dppm) and Fe2(CO)9: simultaneous formation of the μ3-vinylidene MnFePt and μ4-vinylidene PtFe3 clusters. Crystal structure of (η5-C5H5)MnFePt(μ3-CCHPh)(CO)6[η1-Ph2PCH2P(O)Ph2] ☆ ☆☆

Abstract The reaction between [Cp(CO)2MnPt(μ-CCHPh)(η2-dppm)] 2 (1) and [Fe2(CO)9] gives heterometallic MnFePt and PtFe3 vinylidene clusters 2–4, in which diphosphine ligands are coordinated to metal cores in three different modes. In [(η2-dppm)PtFe3(μ4-CCHPh)(CO)9] (2) the Pt atom is chelated by dppm while in [CpMnFePt(μ3-CCHPh)(μ-dppm)(CO)5] (3) dppm bridges the Pt–Fe bond. Complex 3 was shown to exist in two isomeric forms. The novel complex {CpMnFePt(μ3-CCHPh)(CO)6[η1-Ph2PCH2P(O)Ph2]} (4), characterized by X-ray diffraction study, possesses a trimetallic chain core. The diphosphine ligand in 4 links to platinum by only one of phosphorus atoms whereas the second P atom is uncoordinated and oxidized to the phosphineoxide group.

Chemistry of vinylidene complexes XI. Synthesis of trinuclear MnFePt complexes by means of consecutive assembling out of mono- and dimetal vinylidene precursors

The dimetal μ-vinylidene complexes Cp(CO)2MnPt(μ-C = CHPh)L2 (L = tert.-phosphine or -phosphite), which have been obtained by coupling of the mononuclear complex Cp(CO)2Mn=C=CHPh and unsaturated PtL2 unit, add smoothly the Fe(CO)4 moiety to produce trimetal MnFePt compounds. The μ3-vinylidene cluster CpMnFePt(μ3-C=CHPh)(CO)6(PPh3) was prepared in quantitative yields from the reactions of Cp(CO)2MnPt(μ-C=CHPh)(PPh3)L (L = PPh3 or CO) with Fe2(CO)9 in benzene at 20 °C. The phosphite-substituted complexes Cp(CO)2Mnpt(μ-C=CHPh)L2 (L = P(OEt)3 or P(OPri)3) react under analogous conditions with Fe2(CO)9 to give mixtures (2:3) of the penta- and hexacarbonyl clusters, CpMnFePt(μ3-C = CHPh)(CO)5L2 and CpMnFePt(μ3-C = CHPh)(CO)6L, respectively. The similar reaction of the dimetal complex Cp(CO)2MnPt(μ-C = CHPh)(dppm), in which the Pt atom is chelated by dppm = Ph2PCH2PPhPin2 ligand, gives only a 15% yield of the analogous trimetal μ3-vinylidene hexacarbonyl product CpMnFePt(μ3-C = CHPh)(CO)(dppm), but the major product (40%) is the tetranuclear μ4-vinylidene cluster (dppm)PtFe3(μ4-C = CHPh)(CO)9. The IR and 1H, 13C and 31P NMR data for the new complexes are reported and discussed.

Chemistry of vinylidene complexes X. Synthesis and characterization of the vinylidene bridged complexes Cp(CO)2MnPt(μ-CCHPh)(PP) with chelating diphosphine ligands PPdppm, dppe or dppp at the platinum atom

The binuclear μ-vinylidene complex Cp(CO)2MnPt(μ-CCHPh)(PPh3)2 reacts with diphosphines PP Ph2P(CH2)nPPh2, where n=1 (dppm), 2 (dppe) or 3 (dppp), at room temperature to give new complexes of the type Cp(CO)2MnPt(μ-CCHPh)(PP) with chelating disphosphine ligands PP at the Pt atom in quantitative yields. All complexes are characterized by IR and 1H, 13C and 31P NMR spectra. The influence of the nature of the ligands at the Pt atom on the bonding between Pt and the semi-bridging carbonyl group is discussed.

Chemistry of vinylidene complexes. V. The ligand substitution reactions at the platinum atom in complexes Cp(CO)2MnPt(μ-CCHPh)L2

Abstract The dimetal μ-vinylidene complexes Cp(CO)2-MnPt(μ-CCHPh)L2 (L = PPh3 or P(OPri) react with nucleophylic molecules (phosphines, phosphites or CO), without cleavage of a dimetallacycle, to afford the products of substitution of platinum-bound terminal ligands with geometry depending on the nature of an entering ligand. The reaction of Cp(CO)2MnPt(μ-CCHPh)(PPh3)2 and P(OPri) gives Cp(CO)2MnPt(μ-CCHPh)[P(OPri)3]2 and Cp(CO)2- MnPt(μ-CCHPh)[P(OPri)3](PPh3) with the P(OPri)3 group cis to the μ-C atom. The latter is also formed by treating Cp(CO)2MnPt(μ-CCCHPh)[P(OPri)3]2 with PPh3, and as a result of the ligand exchange reaction between bis-phosphine and bis-phosphite compounds. The last ligand redistribution process is reversible, and an equilibrium between all three of the above complexes exists in solution. Treatment of Cp(CO)MnPt(μ-CCHPh)L2 with Co2(CO)8 yields the tricarbonyl complexes Cp(CO)2- MnPt(μ-CCHPh)(L)(CO) with the platinum-bound Co group trans to μ-C. All studied reactions are stereoselective, and no mixed-ligand complexes isomeric to the above species have been detected. The IR and 1H, 13P NMR spectra of the new complexes are discussed.

Chemistry of vinylidene complexes: 15. Transmetallation of μ-vinylidene MnPd complexes. Synthesis, X-ray diffraction analysis, and mass spectrometric study of the (η5-C5H5)MnFe2(μ3-C=CHPh)(CO)8 clustercluster

The reaction of Cp(CO)2Mn=C=CHPh(1) with Pd(PPh3)4 followed by the replacement of the PPh3 ligands by diphosphines Ph2P(CH2)2PPh2 (dppe) or Ph2P(CH2)3PPh2 (dppp) (where dppe is bis(diphenylphosphino)ethane and dppp is 1,3-bis(diphenylphosphino)propane) afforded the binuclear complexes Cp(CO)2MnPd(μ-C=CHPh)(dppe) (2a) and Cp(CO)2MnPd(μ-C=CHPh)(dppp) (2b), respectively. The reactions of2a and2b with Fe2(CO)9 gave the trinuclear complex CpMnFe2(μ3-C=CHPh(CO)3 (3). Competitive transmetallation took the second pathway to yield clusters containing the PdFe3 and PdFe2 cores. Complex3 was also formed in the thermal reaction of compound1 with Fe2(CO)9. Complex3 was studied by IR spectroscopy,1H and13C NMR spectroscopy, mass-spectrometry, and X-ray diffraction analysis.

Chemistry of vinylidene complexes XII. Transmetalation of the μ-vinylidene ligand in the reaction of Cp(CO)2MnPt(μ-CCHPh)(dppp) with Fe2(CO)9. Formation of new PtFe, PtFe2 and PtFe3 complexes

Abstract The reaction between [Fe 2 (CO) 9 ] and [Cp(CO) 2 MnPt(μ-C CHPh)(dppp)] ( 1 ), where dppp is Ph 2 P(CH 2 ) 3 PPh 2 , proceeds stepwise, initially through transmetalation of the bridging vinylidene ligand, i.e. with replacement of the [Mn(CO) 2 Cp] fragment by the [Fe(CO) 4 ] group, to produce the novel binuclear μ-vinylidene complex [(dppp)PtFe(μ-C CHPh)(CO) 4 ] ( 2 ), which reacts further with [Fe 2 (CO) 9 ] to yield the tetranuclear cluster [(dppp)PtFe 3 (μ 4 -C CHPh)(CO) 9 ] ( 3 ) and the trinuclear complex [(dppp)PtFe 2 (CO) 8 ] ( 4 ). The IR and 1 H, 13 C and 31 P NMR data for the new complexes are reported and discussed.

Molecular structure of a new palladium-containing vinylidene cluster [η2-Ph2P(CH2)3PPh2]PdFe3(μ4-C=CHPh)(CO)9

The structure of the vinylidene cluster [η2-Ph2P(CH2)3PPh2]PdFe3(μ4-C=CHPh)(CO)9 was established by X-ray diffraction analysis. The metal core of the molecule has a butterfly shape with the Pd atom occupying a wingtip position. The C(1)=C(2)HPh ligand is σ-bound to three atoms of the Fe2Pd triangle through the C(1) atom and is η2-coordinated to the Fe atom located in the second wingtip position via the C(1)=C(2) double bond. The Pd atom is chelated by the diphosphine ligand.

Infrared study of transformation of a terminal carbonyl ligand into a bridging one in the MnPt and MnPd μ-vinylidene complexes

Abstract The IR study of a series of heterometallic vinylidene-bridged complexes CP(CO) 2 MnM( μ -C = CHPh)LL′, where M = Pt or Pd, L and L′ = CO, tert -phosphites, PPh 3 , Ph 2 P(CH 2 ) n PPh 2 , n = 1–3, demonstrated the existence of a gradual transformation of one of the terminal CO groups at the Mn atom into bridging one spanning the Mn-M bond, which goes through the intermediate semi-bridging form and is induced by the electron-donating capacities of ligands L and L′ at the M atom.