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PPh3 Ligands (pph3 + ligand)

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Chemistry100%

Selected Abstracts

Synthesis and crystal structure of three nido 11-vertex platinaborane clusters

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2005
Jianmin Dou
Abstract The reaction of [PtCl2(PPh3)2] with closo -B10H102, in ethanol under reflux conditions gave two nido 11-vertex platinaundecaborane clusters: [(PPh3)2PtB10H10 -8,10-(OEt)2]·CH2Cl2(1) and [(PPh3)2PtB10H11 -11-OEt]·CH2Cl2(2). A novel B10H102, deboronated nido 11-vertex diplatinaundecaborane [(µ-PPh2)(PPh3)2Pt2B9H6 -3,9,11-(OEt)3]·CH2Cl2(3) was obtained when the same reaction was carried out under solvothermal conditions. All of these compounds were characterized by infrared spectroscopy, NMR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Both clusters 1 and 2 have a nido 11-vertex {PtB10} polyhedral skeleton in which the Pt atom lies in the open PtB4 face. Each Pt atom connects with four B atoms and two P atoms of the PPh3 ligands. Cluster 3 has a nido 11-vertex {Pt2B9} polyhedral skeleton in which two Pt atoms sit in neighbouring positions of the open Pt2B3 face, bridged by a PPh2 group. Each Pt atom connects three B atoms and a P atom of the PPh3 ligand. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Formation of (,-Alkenyl)- and (,-Vinylidene)palladium and -platinum Complexes by Oxidative Addition of 4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene , The Molecular Structure of an Unusual Asymmetric (,-Vinylidene)Pd,Pd Complex

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2003
Michael Knorr
Abstract 4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene (1) oxidatively adds to [Pd(PPh3)4] and [Pt(C2H4)(PPh3)2] giving rise to the ,-alkenyl complexes trans -[MCl{[C(Cl)=C(H),N=CPh2]}(PPh3)2] (2a: M = Pd; 2b: M = Pt). When 1 is treated with [Pd(PPh3)4] in a 1:2 ratio in refluxing toluene, the dimetallic ,-vinylidene complex [(PPh3)ClPd{,-[C=C(H),N=CPh2]}PdCl(PPh3)2] (3) is formed. In this fluxional compound, a PPh3 ligands migrates in a reversible manner between the two Pd centers. Substitution of the PPh3 ligands of 3 by 2 equiv. of Ph2PCH2PPh2 affords the A-frame complex [ClPd(,-dppm)2{,-[C=C(H),N=CPh2]}PdCl] (4). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Synthesis of Ruthenium Hydride Complexes Containing beta-Aminophosphine Ligands Derived from Amino Acids and their use in the H2 -Hydrogenation of Ketones and Imines

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2005
Kamaluddin Abdur-Rashid
Abstract The new complexes RuHCl(PPh2CH2CHRNH2)2 and RuHCl(PPh2CH2CHRNH2)(R- binap), R=H (Pgly), R=Me [(R)-Pala] were prepared by the substitution of the PPh3 ligands in RuHCl(PPh3)3 or RuHCl(PPh3)[(R)-binap] with beta-aminophosphines derived from amino acids. The complex trans -RuHCl(Pgly)[(R)-binap] has been characterized by X-ray crystallography. The complex trans -RuHCl[(S)-Ppro]2 where (S)-Ppro is derived from proline was also prepared and characterized by X-ray crystallography. These were used as catalyst precursors in the presence of a base (KOPr- i or KOBu- t) for the hydrogenation of various ketones and imines to the respective alcohols and amines with H2 gas (1,11 atm) at room temperature. Acetophenone was hydrogenated to (S)-1-phenylethanol in low ee (up to 40%) when catalyzed by the enantiomerically pure complexes. These complexes are especially active in the hydrogenation of sterically congested and electronically deactivated ketones and imines and are selective for the hydrogenation of CO bonds over CC bonds. [source]

Synthesis and crystal structure of three nido 11-vertex platinaborane clusters

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 11 2005
Jianmin Dou
Abstract The reaction of [PtCl2(PPh3)2] with closo -B10H102, in ethanol under reflux conditions gave two nido 11-vertex platinaundecaborane clusters: [(PPh3)2PtB10H10 -8,10-(OEt)2]·CH2Cl2(1) and [(PPh3)2PtB10H11 -11-OEt]·CH2Cl2(2). A novel B10H102, deboronated nido 11-vertex diplatinaundecaborane [(µ-PPh2)(PPh3)2Pt2B9H6 -3,9,11-(OEt)3]·CH2Cl2(3) was obtained when the same reaction was carried out under solvothermal conditions. All of these compounds were characterized by infrared spectroscopy, NMR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Both clusters 1 and 2 have a nido 11-vertex {PtB10} polyhedral skeleton in which the Pt atom lies in the open PtB4 face. Each Pt atom connects with four B atoms and two P atoms of the PPh3 ligands. Cluster 3 has a nido 11-vertex {Pt2B9} polyhedral skeleton in which two Pt atoms sit in neighbouring positions of the open Pt2B3 face, bridged by a PPh2 group. Each Pt atom connects three B atoms and a P atom of the PPh3 ligand. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Organometallic chemistry on rhodaheteroborane clusters: reactions with bidentate phosphines and organotransition metal reagents,

APPLIED ORGANOMETALLIC CHEMISTRY, Issue 6-7 2003
Oleg Volkov
Abstract This article reviews our recent work on the reactions of the rhodaheteroboranes [8,8-(PPh3)2 - nido -8,7-RhSB9H10] (1) and [9,9-(PPh3)2 - nido -9,7,8-RhC2B8H11] (2), and their derivatives, with the bidentate phosphines, dppe [(CH2)2(PPh2)2], dppp [(CH2)3(PPh2)2], and dppm [CH2(PPh2)2], and also with organotransition metal reagents. Simple substitution of the two PPh3 ligands by a single bidentate phosphine takes place when a 1 : 1 molar ratio of base (dppe or dppp) to rhodathiaborane (1) is used. However, in the presence of an excess of dppe or dppp, products containing 1 or 2 mol of base are formed. These products include a bidentate ligand on the metal and a monodentate ligand on the cage. The displaced hydrogen atom from the cage has moved to the metal center. These bis(ligand) species are unstable with respect to the loss of dihydrogen, affording closo -11 vertex clusters with a pendent phosphine ligand on the cage. In concentrated solutions, the pendent phosphine attacks another cage to afford linked clusters. Under both sets of conditions, when dppm is used, only one product is observed. This species has two dppm ligands coordinated to the metal: one in a unidentate mode and the other bidentate. A similar product is obtained in the reaction of 2 with dppm, although the arrangement of the ligands on the metal in the product is different. Ligand exchange experiments on the dppm,thiaborane system lead to results that provide keys to the reaction pathways in some of these processes. The bis(dppm) derivatives of 1 and 2 are amenable to further derivatization. A second metal may be added, either as an exo -polyhedral atom in a nido cluster in which the metal is part of a bidentate ligand, in the case of 1 and 2, or in a closo cluster derivative of 1 in which the metal is bonded to a dangling PPh2 moiety. Thus, it was possible to add the metals iridium, rhodium or ruthenium to the cluster, in the case of 1 and ruthenium in the case of 2. However, the reaction of more electrophilic organotransition metal reagents, such as Wilkinson's catalyst, with the dppm derivative of 1 affords species resulting from removal of ligand rather than incorporation of metal, and the products shed light on the rearrangement processes in these systems. Copyright © 2003 John Wiley & Sons, Ltd. [source]

(4,6-Dimercapto-1,3,5-triazine-2-thiol­ato- S2)­tris­(tri­phenyl­phosphine- P)gold(I) di­methyl­form­amide solvate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2000
Yingjun Zhao
In the title compound, [Au(C3H2N3S3)(C18H15P)3]·C3H7NO, the AuI atom has a distorted tetrahedral geometry consisting of one uncoordinated di­methyl­form­amide mol­ecule, one tri­thio­cyanurate ligand and three PPh3 ligands. The S,Au distance is 2.909,(2),Å, and the P,Au distances fall in the range 2.400,(14),2.4074,(13),Å. The S,Au,P angles are 92.81,(6), 99.17,(6) and 104.21,(5)°, and the P,Au,P angles are 114.46,(5), 119.04,(5) and 119.66,(5)°. [source]

Highly Efficient Redox Isomerization of Allylic Alcohols at Ambient Temperature Catalyzed by Novel Ruthenium,Cyclopentadienyl Complexes,New Insight into the Mechanism

CHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2005
Belén Martín-Matute Dr.
Abstract A range of ruthenium cyclopentadienyl (Cp) complexes have been prepared and used for isomerization of allylic alcohols to the corresponding saturated carbonyl compounds. Complexes bearing CO ligands show higher activity than those with PPh3 ligands. The isomerization rate is highly affected by the substituents on the Cp ring. Tetra(phenyl)methyl-substituted catalysts rapidly isomerize allylic alcohols under very mild reaction conditions (ambient temperature) with short reaction times. Substituted allylic alcohols have been isomerized by employing Ru,Cp complexes. A study of the isomerization catalyzed by [Ru(Ph5Cp)(CO)2H] (14) indicates that the isomerization catalyzed by ruthenium hydrides partly follows a different mechanism than that of ruthenium halides activated by KOtBu. Furthermore, the lack of ketone exchange when the isomerization was performed in the presence of an unsaturated ketone (1 equiv), different from that obtained by dehydrogenation of the starting allylic alcohol, supports a mechanism in which the isomerization takes place within the coordination sphere of the ruthenium catalyst. [source]