0000000000328334
AUTHOR
Jorge Payá
ortho-metallation of P(m-MeC6H4)3 in dirhodium(II) tetraacetate. Molecular structure of Rh2(O2CCH3)2[(m-MeC6H3)P(m-MeC6H4)2]2(HO2CCH3)2·CH3CO2H
Abstract The thermal reaction of Rh2(O2CCH3)4(MeOH)2 and P(m-MeC6H4)3 in a 1:2 molar ratio in acetic acid yielded Rh2(O2CCH3)2[(m-MeC6H3)P(m -MeC6H4)2]2(HO2CCH3)2. Purple monoclinic crystals of this compound and one molecule of acetic acid, space group P21/c, were obtained by evaporation of a solution of the original reaction product in acetic acid/CH2Cl2 mixture. The unit cell parameters are a = 21.346(3), b = 11.909(2), c = 20.071 A, β = 97.98(1)° and Z = 4. The structure consists of a dinuclear rhodium core bridged by cisoid acetate groups and two ortho-metallated phosphine ligands. The ortho-metallation occurs at the least sterically hindered carbon atom which is trans to the methyl sub…
Fast orthometalation reactions at a binuclear dirhodium(II) complex. Synthesis, crystal structure and reactivity of Rh2(O2CCH3)3[(C6H4)PPh2]·(HO2CCH3)2
Abstract From the reaction of Rh2(O2CCH3)4(MeOH)2, in hot acetic acid with PPh3 the monometalated intermediate Rh2(O2CCH3)3[(C6H4)PPh2](HO2CCH3)2 has been isolated and characterized by an X-ray study. This compound rapidly reacts with an excess of PPh3 in dichloromethane at room temperature to give Rh2(O2CCH3)2-[(C6H4)PPh2]2(PPh3)2 with a head-to-tail structure. The same procedure at higher temperatures gives a mixture of this compound and another doubly metalated compound with a head-to-head structure.
Synthesis and solution behavior of some bis[2-{(dimethylamino)methyl}phenyl]gold(III) complexes
Abstract [Au(2-C6H4CH2NMe2)Cl2] reacts with [Hg(2-C6H4CH2NMe2)2] (2/1) or with [Hg(2-C6H4CH2- NMe2)Cl] (1/1) both in the presence of an excess of [Me4N]Cl to give [Au(2-C6H4CH2NMe2)2Cl] (1) which reacts with KCN or AgClO4 to give [Au(2- C6H4CH2-NMe2)2CN] (2) or [Au(2-C6H4CH2- NME2)2]ClO4 (3), respectively. The solution behavior of these complexes is studied by NMR spectroscopy.
Orthometallation reaction in dirhodium(II) compounds. Selective formation of doubly-metallated compounds with head-to-head structure
Abstract The reaction of the mono-metallated compound Rh 2 (O 2 CCH 3 ) 3 [(C 6 H 4 )P(CH 3 ) (C 6 H 5 )]·2(HO 2 CCH 3 ) with PPh 3 (1:1 molar ratio) has been studied by 31 P NMR spectroscopy. The reaction yields the doubly-metallated compound Rh 2 (O 2 CCH 3 ) 2 [(C 6 H 4 ) P(CH 3 )(C 6 H 5 )]p(C 6 H 4 )P(C 6 H 5 ) 2 ]·2(HO 2 CCH 3 ) with a head-to-head (H-H) configuration. An intermediate reaction compound, not previously observed, has been spectroscopically detected in solution. Analogous intermediate compounds have been detected using P( p -CH 3 C 6 H 4 ) 3 and P( p -ClC 6 H 4 ) 3 instead of triphenylphosphine.
Reactions of rhodium trifluoroacetate with triphenylphosphine and pyridine. Molecular structure of Rh2(O2CCF3)4(py)4
Abstract Rh 2 (O 2 CCF 3 ) 4 reacts with two mol of triphenylphosphine forming the adduct Rh 2 (O 2 CCF 3 ) 4 (PPh 3 ) 2 . This compound in solution, even at room temperature, undergoes slow stepwise orthometalation of the phosphine ligands forming the doubly metalated compound Rh 2 (O 2 CCF 3 ) 2 [(C 6 H 4 )P(C 6 H 5 ) 2 ] 2 . This reaction has been monitored by 31 P NMR spectroscopy detecting in solution three reaction intermediates. Rh 2 (O 2 CCF 3 ) 4 reacts with excess of pyridine to form the compound Rh 2 (O 2 CCF 3 ) 4 (py) 4 that can be structurally classified as a class III adduct. It contains two bridging and two monodentate equatorial carboxylates and two equatorial and two axial…
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
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.
Synthesis of orthometallated rhodium(III) compounds. Crystal structures of [RhCl2{η2(C6H4)PPh2}(η2-dppm)] and [RhCl{η2(C6H4)PPh2}(η1-PCCl)(phen)] (SbF6)·CH2Cl2 (dppm=bis(diphenylphosphino)methane; PCCl=P(o-ClC6H4)Ph2; phen=1,10 phenanthroline)
Abstract Neutral and cationic rhodium(III) metallated compounds containing a four-membered ring are prepared by different synthetic methods: (i) from rhodium(I) compounds that contain the ligand P( o -ClC 6 H 4 )PPh 2 , by 2c-2e intramolecular oxidative addition; (ii) from metallated dirhodium(II) compounds; (iii) by ligand substitution in [RhCl 2 {η 2 -(C 6 H 4 )PPh 2 }{η 2 -P( o -ClC 6 H 4 )Ph 2 }]. The crystal structures of [RhCl 2 {η 2 -(C 6 H 4 )PPh 2 }(η 2 -dppm)] ( 2 ) and of the dichloromethane solvate of [RhCl{η 2 -(C 6 H 4 )PPh 2 }{η 1 -P( o -ClC 6 H 4 )Ph 2 }(phen)](SbF 6 ) ( 11 ) have been determined by X-ray diffraction methods. In both complexes the Rh atom is in the distorted…
Reactions of dirhodium(II) monometallated compounds with phosphines. Factors affecting the reactivity and the structure of the doubly-metallated compounds. Molecular structure of Rh2(O2CCH3)2[(C6H4)P(C6H5)2][(p-ClC6H3)P(p-ClC6H4)2] · (HO2CCH3)2·(C6H6), a compound with two different metallated phosphines
Abstract Monometallated compounds of formula Rh2(O2CCH3)3[(p-XC6H3)P(p-XC6H4)2](HO2CCH3)2 (X=CH3, Cl) have been prepared in good yield. The reactions with p-substituted triarylphosphines P(p-X′C6H4)3 (X′=CH3, H, Cl) have been studied. For X=X′ and [P]/[Rh2]=1 all the resulting doubly metallated compounds Rh2(O2CCH3)2[(p- XC6H3)P(p-XC6H4)2](HO2CCH3)2 (X=CH3, Cl) have head-to-tail (H-T) structure. For [P]/[Rh2]=3 reaction progress is observed at room temperature. When X=X′ a 1:1 mixture of H-T and H-H compounds is formed for X=Cl but only the H-H compound is obtained for X=CH3. For X ≠ X′ mixtures of H-T and H-H compounds are obtained. The entering phosphine, and to a less extent the phosphin…