Bridging Phosphido Research Articles

Lineare Oligophosphaalkane, XI [1] Stabilisierung von Phosphiniden, PH, im Clusteryerband — Röntgenstrukturanalyse von Fe4(CO)10[(μ2-PPri)2CH2](μ2-PPriMe)(μ2-H)(μ4-PH)

Abstract Reaction of HPriP-CH2-PPriH with Fe2(CO)9 in a molar ratio of 1:2 produces a mixture of cluster compounds from which Fe4(CO)10[(μ2-PPri)2CH2](μ2-PPriMe)(μ2-H)(μ4-PH) could be isolated by liquid chromatography. X-ray structural analysis shows a planar trapezoid arrangement for the four iron atoms (Fe1 -Fe2 2,648(1), Fe2 -Fe3 2,790(1), Fe3 -Fe4 2,643(1), Fe1 --Fe4 4,109(1) Å ) capped by the novel bidentate phosphido bridge (μ2-PPri)2CH2 and the unsubstituted phosphinidene, PH( Fe1 - P4 2,284(1), Fe2 - P4 2,410(1), Fe3 - P4 2,405(1), Fe4 - P4 2,288(1), P4 - H1 1,39(4) Å).

Reactivity of phosphido-bridged heteronuclear compounds: insertion of carbon monoxide and diphenylacetylene into the phosphido bridge of RuCo(CO)7(.mu.-PPh2). X-ray structure of RuCo(CO)5(.mu.-CO)[.mu.-.eta.2-PPh2C(O)C(Ph)C(Ph)

Reactivity of phosphido-bridged heteronuclear compounds: insertion of carbon monoxide and diphenylacetylene into the phosphido bridge of RuCo(CO)7(.mu.-PPh2). X-ray structure of RuCo(CO)5(.mu.-CO)[.mu.-.eta.2-PPh2C(O)C(Ph)C(Ph)

Coupling of bridging phosphido ligands with alkyl, hydride, and carbene ligands to give bridge elimination reactions

Described are some examples of the degradation of phosphido bridges via coupling with alkyl hydrides and carbene ligands. The experiments outlined demonstrate that the phosphide bridges are not inert and that they can participate in complex reactions. Such bridge elimination reactions may limit the utility of phosphide-bridged complexes in homogenous catalysis.

Interconversion of phosphido-bridged polynuclear cobalt carbonyl complexes. Cleavage of the phosphido bridge during hydroformylation catalysis

Interconversion of phosphido-bridged polynuclear cobalt carbonyl complexes. Cleavage of the phosphido bridge during hydroformylation catalysis

Phosphorus-31 nuclear magnetic resonance studies of phosphido-bridged dinuclear complexes of palladium and platinum

Proton decoupled 31P nmr spectra are reported for a series of dinuclear metal complexes containing bridging dialkyl- or diarylphosphido groups: [M2Cl2(μ-PR′2)2(PR3)2], M = Pd, R′ = Ph, R3 = Et3 or HPh2; M = Pd, R′ = Me, R3 = Et3, Ph3, or HMe2; M = Pt, R′ = Ph, R3 = Et3 or HPh2; and [M2(μ-PPh2)2(dppe)2]Cl2, M = Pd, or Pt, dppe = Ph2P(CH2)2PPh2. Detailed analysis and computer simulation of the spectra in the AA′XX′, AA′XX′M, AA′A″A′′′XX′, and AA′A′′A′′′XX′M spin systems leads to the following ranges and relative signs for coupling constants involving the bridging phosphorus atoms: 2J(R3P—cis PR′2), M = Pt, −1 to +5 Hz, M = Pd, +20 to +32 Hz; 2J(R3P—transPR′2), M = Pt, +291 to +396 Hz, M = Pd, +311 to +443 Hz; 2J(R2P—cis PR2), M = Pt, −162 to −208 Hz, M = Pd, −261 to −350 Hz (the assignment of negative signs to these couplings is not completely certain); 1J(Pt—PR2), trans to Cl, +2364 to +2635 Hz, trans to PR3, +1690 to +1992 Hz. Resonances due to the bridging phosphido groups occur at very high field (−267 to −322 ppm upfield of P(OCH3)3), in strong contrast to literature reports of phosphido bridges in palladium cluster complexes where the bridged metal atoms are linked by a metal–metal bond and the bridging phosphorus occurs +57 to +82 ppm downfield of P(OCH3)3.

Open and closed ruthenium and osmium clusters with μ 3-acetylide and phosphido bridges

The synthesis and structural characterisation of “open” M 3(CO) 9 (CCR)(PPh 2) (M = Ru, Os; R = i-Pr, t-Bu) clusters with μ 3-acetylides and phosphido groups bridging an “open” edge of the M 3 triangle are described. Facile conversion of Ru 3(CO) 9 (CCR)(PPh 2) to “closed” Ru 3(CO) 8 (CCR)(RPh 2) occurs via loss of CO and metal—metal bond formation, a process which is reversible under one atmosphere of CO.

Stereochemie der Metall-Metall-Bindung: Darstellung und Struktur von Co2(CO)4C5H5P(CH3)2 / Stereochemistry of the Metal-Metal Bond: Preparation and Structure of Co2(CO)4C5H5P(CH3)2

Abstract The title complex 4 was prepared from η-C3H5Co(CO)3 and η-C5H5(CO)Co-P(CH3)2H. It completes the series of PR2-and AsR2-bridged homodinuclear complexes C2(CO)7C5H5-As(CH3)2, Mn2(CO)6C5H5As(CH3)2, and Fe2(CO)5C5H5P(CH3)2. Its crystal structure analysis reveals the systematic variation of the ligand distribution along the series which depends only on the number of ligands present and not on given coordination geometries. The metal-metal bond length in 4 is mainly determined by the stereochemical require-ments of the bridging phosphido ligand.

Reactions of metal carbonyl derivatives X. The synthesis and reactivity of some dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups

The tertiary phosphine π-C 5H 5Fe(CO) 2P(C 6H 5) 2 reacts with a suspension of Fe 2(CO) 9 in benzene to give the dinuclear complex π-C 5H 5Fe 2P(C 6H 5) 2(CO) 6. This compound is also obtained by nucleophilic attack of [π-C 5H 5Fe(CO) 2] − on Fe(CO) 4-[P(C 6H 5) 2Cl] in tetrahydrofuran. Irradiation of a benzene solution of π-C 5H 5Fe 2-P(C 6H 5) 2(CO) 6 with ultraviolet light affords π-C 5H 5Fe 2P(C 6H 5) 2(CO) 5 which contains both a bridging carbonyl and a bridging phosphido group. The unstable bridged sulphido derivatives π-C 5H 5Fe 2SR(CO) 6 (R = CH 3 and C 6H 5) and π-C 5H 5Fe 2(t-C 4H 9S)(CO) 5 are similarly obtained employing π-C 5H 5Fe(CO) 2SR as ligand. The reactions of π-C 5H 5Fe 2P(C 6H 5) 2(CO) 5 with tertiary phosphines and phosphites yield three types of products depending on the reaction conditions and the ligand involved. Examples include π-C 5H 5Fe 2P(C 6H 5) 2(CO) 4P(C 6H 5) 3, a mono-substituted derivative of π-C 5H 5Fe 2P(C 6H 5) 2(CO) 5, and π-C 5H 5Fe 2P(C 6H 5) 2(CO) 5P(C 2H 5) 3 and π-C 5H 5Fe 2P(C 6H 5) 2(CO) 4[P(OCH) 3) 3] 2, mono- and bis-substituted derivatives of π-C 5H 5Fe 2P(C 6H 5) 2(CO) 6, respectively. The reaction of π-C 5H 5Fe 2P(C 6H 5 2(CO) 5 with (C 6H 5) 2PCH 2P(C 6H 5) 2 in benzene under reflux affords [π-C 5H 5Fe 2P(C 6H 5) 2(CO) 4](C 6H 5) 2PCH 2P(C 6H 5) 2 in which the ditertiary phosphine bridges two iron atoms.

Some novel dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups

Some novel dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups