Search results for "phosphine"
showing 10 items of 618 documents
Analysis of the main structural trends for biscyclometalated dinuclear rhodium compounds with nitrogen donor axial ligands
2009
A new series of biscyclometalated dinuclear rhodium(II) compounds with the general formula Rh 2 (O 2 CR) 2 (PC) 2 · (N) 2 have been obtained, where PC is a cyclometalated phosphine, R an aliphatic group, and N a nitrogen donor ligand. The crystal structures for these compounds have been determined by X-ray diffraction. The most important structural trends have been analyzed, and have also been compared with the same parameters for different analogous compounds described previously in the literature.
Selective ortho-metallation reaction of the phosphine P(o-ClC6H4)Ph2. Synthesis and crystal structure of [Rh2(μ-O2CCH3)3(μ-(ClC6H3)PPh2(OH2)2]·CHCl3
1993
Abstract From the reaction of [Rh2(O2CCH3)4(MeOH)2] in hot acetic acid with P(o-ClC6H4)Ph2, two monometallated compounds [Rh2(O2CCH3)3(C6H4)P(o-ClC6H4)Ph(HO2CCH3)2] (1), already described, and [Rh2(O2CCH3)3{(ClC6H3)PPh2}(OH2)2] have been isolated. The new compound has been characterized by an X-ray study. It crystallizes in the triclinic space group P1. It contains three acetate groups bridging a Rh24+ unit that has a Rh-Rh bond distance of 2.426(1) A; the fourth bridging ligand is derived from one P(o-ClC6H4)Ph2 metallated in the halogenated ring. The two water molecules occupy the axial coordination sites.
Orthometalation reactions in trifluoroacetate dirhodium(II) compounds. Molecular structure of Rh2(O2CCF3)2[(C6H4)PPh2]2·(PPh3)2·2(C7H8)
1994
Abstract Rh 2 (O 2 CCF 3 ) 3 [(C 6 H 4 )PPh 2 ]·(HO 2 CCF 3 ) 2 reacts with PPh 3 yielding the doubly metalated compound Rh 2 (O 2 CCH 3 ) 2− [(C 6 H 4 )PPh 2 ] 2 ·(HO 2 CCF 3 ) 2 . The reaction proceeds via a reactive intermediate with an equatorial phosphine, Rh 2 (η 2 -O 2 CCF 3 )(μ-O 2 CCF 3 ) 2 [(C 6 H 4 )PPh 2 ](PPh 3 )·(HO 2 CCF 3 ), which can also be generated in moderate yield under photochemical conditions. The structure of the PPh 3 bis-adduct Rh 2 (O 2 CCF 3 ) 2 [(C 6 H 4 )PPh 2 ] 2 ·(PPh 3 ) 2 ·2(C 7 H 8 ) has been determined by X-ray diffraction. M r =1663.27, orthorhombic, space group Fdd 2, a =41.748(9), b =21.620(5), c =17.375(5) A, V =15683(6) A 3 , Z =8, D x =1.41 g cm −3…
Simultaneous substitution of bridging acetate groups and reversible RhC bond cleavage in [Rh2(O2CCH3)3-{(C6H4)PPh2}(HO2CCH3)2] in the presence of CF…
1993
Abstract The reaction of the monometallated compound [Rh2(O2CCH3)3 {(C6H4)PPh2}(HO2CCH3)2] (1) with CF3CO2H at room temperature yields [Rh2(O2CCF3)3{(C6H4)PPh2}(HO2CCF3)2] (3) as the only isolable product. Compound 3 has been characterized by X-ray methods. 3 crystallizes in the space group P21 / n. It contains three trifluoroacetate groups bridging a Rh4+2 unit with a RhRh bond distance of 2.438(1) Ă; the fourth bridging ligand is a triphenylphosphine metallated at one of the ortho positions. Two molecules of trifluoroacetic acid occupy the axial coordination positions. In addition to the substitution of acetate groups, reversible electrophilic RhC bond activation is observed.
Molecular structure of the compound [Rh2(O2CCH3)3{(C6H4)P(BrC6H4-1,2)(C6H5)} · (HO2CCH3)2].Kinetic study of the exchange reaction of acetate groups w…
1993
Abstract The compound [Rh 2 (O 2 CCH 3 ) 3 {(C 6 H 4 )P(BrC 6 H 4 -1,2) (C 6 H 5 )} · (HO 2 CCH 3 ) 2 ] has been isolated in high yield from the thermal reaction of dirhodium tetraacetate and the phosphine P(BrC 6 H 4 -1,2) (C 6 H 5 ) 2 in acetic acid. The structure of this compound has been determined by X-ray diffraction; it crystallizes in the P 1 (triclinic) space group and contains three acetate groups bridging a Rh 2 4+ unit the RhRh distance being 2.432(1)A; the fourth bridging ligand is an ortho -bromophenyldiphenylphosphine metallated at one of the ortho positions of the unsubstituted phenyl rings. Two molecules of acetic acid occupy the axial coordination positions. Stepwise exch…
Synthesis and structural studies of 2-stannyl-substituted ferrocenylmethylamine and -phosphine derivatives 2-Me2RSnFcCH2Y (RMe, Cl; YNMe2, PPh2, P(…
1995
Abstract 2-(Trimethylstannyl)ferrocenylmethyldiphenylphosphine, 2-Me3SnFcCH2PPh2 (2a), was synthesized from 2-Me3SnFcCH2NMe2 (1a) and Ph2PH. Compound 2a is oxidized with H2O2 to 2-Me3SnFcCH2P(O)Ph2 (3a). Halogenation of 1a and 2a with Me2SnCl2 and 3a with HCl-diethyl ether yields the organotin monochlorides 2-Me3(Cl)SnFcCH2Y ( 1b , Y = NMe 2 ; 2b , Y = PPh 2 3b , Y = P ( O ) Ph 2 ) . Both crystal structure determinations and multinuclear magnetic resonance studies in solution reveal for 1b–3b molecular structures in which the tin atom approaches a trigonal bipyramidal pentacoordination as a consequence of an intramolecular Y Sn interaction. The donor strength of Y increases in the order PPh2
Cyclometallation reactions in complexes of the type Rh(oq)(CO)(P(o-BrC6F4)Ph2)
1986
Abstract The reaction of Rh(oq)(CO)(PCBr) (PCBr = P(o-BrC6F4)Ph2; oq = 8-oxyquinolinte)_ in refluxing toluene in the presence of Et4NBr (1/4 molar ratio) gives Rh(oq)Br(PC) (H2O), PC = P (o-C6F4)Ph2, in practically quantitative yield. The water molecule is readily displaced by various P-donor ligands to give complexes of general formula Rh(oq)Br(PC) PR3 (PR3 = PPh3, P(p-MeC6H4)3, P(p-MeOC6H4)3, P(p-FC6H4)3, P(PMe)3 and P(OPh3). The molecular structure of the compound Rh(oq)Br(PC) (PPh3) has been determined by X-ray methods. Crystals of the title compound are monoclinic, space group P21/n with unit cell dimensions a 11.273(4), b 20.087(8), c 17.471(7) A and β 102.15(8)°. The final R for 2304…
Metallophilicity-assisted assembly of phosphine-based cage molecules.
2014
A family of supramolecular cage molecules has been obtained via self-assembly of the phosphine-gold coordination complexes following an aurophilicity-driven aggregation approach. Use of the di- (PP) or tridentate (PPP) phosphine ligands Pn (n = 2, 3) with rigid polyaromatic backbones leads to clean formation of the coordination Pn(Au(tht))n(n+) species, sequential treatment of which with H2O/NEt3 and excess of H2NBu(t) gives the finite 3D structures of two major types. The cylindrical-like hexametallic cages [(PPAu2)3(μ3-NBu(t))2](2+) are based on the diphosphines PP = 1,4-bis(diphenylphosphino)benzene (1), 4,4'-bis(diphenylphosphino)biphenyl (2), 4,4"-bis(diphenylphosphino)terphenyl (3), w…
Bimetallic ruthenium-tin chemistry: synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands
2010
A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl2 and the corresponding arene ruthenium dichloride dimers [(η6-arene)Ru(μ2-Cl)Cl]2 (arene = C6H6, PriC6H4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η6-C6H6)Ru(PPh3)(SnCl3)Cl] (1) and [(η6-PriC6H4Me)Ru(PPh3)(SnCl3)Cl] (2), the neutral di(trichlorostannyl) complex [(η6-PriC6H4Me)Ru(NCPh)(SnCl3)2] (3) could be obtained for the para-cymene derivative with benzonitrile as additional ligand. By contrast, the analogous reaction with the benzene derivative leads to a salt compose…
"Through-space" 31P spin-spin couplings in ferrocenyl tetraphosphine coordination complexes: improvement in the determination of the distance depende…
2008
Abstract From the analysis of several nickel and palladium halide complexes of a constrained ferrocenyl tetraphosphine, the existence in solution phase of unique 31P–31P “through-space” nuclear spin–spin coupling constants (JPP) had been previously evidenced. Due to the blocked conformation of the species in solution, and based on the NMR spectra obtained for the complexes and their corresponding solid state X-ray structures, these JPP constants had been shown to clearly depend on the mutual spatial position of the corresponding phosphorus atoms. Herein, the quantitative correlation disclosed at that time (P⋯P distance dependence of coupling constants) is remarkably confirmed, and mathemati…