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Book Synthesis and Reactivity of Nickel Palladium and Platinum Phosphine Complexes with Hydridoamido Hydridophenoxo and Dithiooxalato Ligands

Download or read book Synthesis and Reactivity of Nickel Palladium and Platinum Phosphine Complexes with Hydridoamido Hydridophenoxo and Dithiooxalato Ligands written by Robert L. Cowan and published by . This book was released on 1989 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis Reactivity and Catalytic Applications of Ruthenium and Palladium Complexes Supported by New Pincer Ligands

Download or read book Synthesis Reactivity and Catalytic Applications of Ruthenium and Palladium Complexes Supported by New Pincer Ligands written by Morgan C. MacInnis and published by . This book was released on 2011 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT continued: These transfer hydrogenation studies are among the first catalytic studies of silyl-pincer complexes and establish [R-PSiP]M species as viable candidates for catalysis. The synthesis and reactivity of 4- and 5-coordinate RuII complexes featuring the [Cy-PSiP] ligand were explored. Reaction of [Cy-PSiP]H with [(p-cymene)RuCl2]2 in the presence of NEt3 and PCy3 resulted in the formation of ([Cy-PSiP]RuCl)2, which serves as a precursor to a series of unprecedented 4-coordinate, formally 14-electron [Cy-PSiP]RuX (X = NHAr, N(SiMe3)2, OtBu) complexes that feature an unusual trigonal pyramidal geometry at Ru. The reactivity of these novel diamagnetic complexes is described, including the reaction of [Cy-PSiP]RuOtBu with amine-boranes resulting in the formation of rare bis(?-BH) complexes. Computational studies confirmed the key role of the strongly ?-donating silyl group of the Cy-PSiP ligand in facilitating the synthesis of such low-coordinate Ru species and enforcing the unusual trigonal pyramidal geometry. The mechanism of ammonia-borane activation was also examined computationally. Lastly, the synthesis and structural characterization of PdII complexes supported by the pincer-like bis(amino)phosphido ligand [?3-(2-Me2NC6H4)2P]- ([NPN]) is described. Examples of ?1-, ?2-, and ?3-NPN coordination to Pd are described, as is the catalytic activity of ([NPN]PdX)2 (X = Cl, OAc, OTf) complexes in the Heck olefin arylation reaction. In an effort to discourage the formation of phosphido-bridged dinuclear complexes, pre-coordination of the Lewis acid BPh3 to [NPN] was pursued. Upon reaction of [N(P?BPh3)N]K with [PdCl(C3H5)]2, the ?1-allyl complex [?3-N(P?BPh3)N]Pd(?1-C3H5) was isolated, which establishes the coordination of a Lewis acid to the phosphido donor of the [NPN] ligand as a viable strategy for encouraging the formation of mononuclear ?3-NPN complexes.

Book Higher Oxidation State Organopalladium and Platinum Chemistry

Download or read book Higher Oxidation State Organopalladium and Platinum Chemistry written by Allan J. Canty and published by Springer. This book was released on 2011-02-25 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kyle A. Grice, Margaret L. Scheuermann and Karen I. Goldberg: Five-Coordinate Platinum(IV) Complexes.- Jay A. Labinger and John E. Bercaw: The Role of Higher Oxidation State Species in Platinum-Mediated C-H Bond Activation and Functionalization.- Joy M. Racowski and Melanie S. Sanford: Carbon-Heteroatom Bond-Forming Reductive Elimination from Palladium(IV) Complexes.- Helena C. Malinakova: Palladium(IV) Complexes as Intermediates in Catalytic and Stoichiometric Cascade Sequences Providing Complex Carbocycles and Heterocycles.- Allan J. Canty and Manab Sharma: h1-Alkynyl Chemistry for the Higher Oxidation States of Palladium and Platinum.- David C. Powers and Tobias Ritter: Palladium(III) in Synthesis and Catalysis.- Marc-Etienne Moret: Organometallic Platinum(II) and Palladium(II) Complexes as Donor Ligands for Lewis-Acidic d10 and s2 Centers.

Book Synthesis Reactivity and Catalytic Applications of Palladium and Platinum Complexes Containing Rigid Bidentate Nitrogen Ligands

Download or read book Synthesis Reactivity and Catalytic Applications of Palladium and Platinum Complexes Containing Rigid Bidentate Nitrogen Ligands written by Robert van Asselt and published by . This book was released on 1993 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Investigations of the Reactivity of Palladium and Platinum Complexes with Molecular Oxygen and Characterization of a Gold III alkene Complex

Download or read book Investigations of the Reactivity of Palladium and Platinum Complexes with Molecular Oxygen and Characterization of a Gold III alkene Complex written by Margaret Louise Scheuermann and published by . This book was released on 2013 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the reactivity of metal complexes with molecular oxygen will facilitate the development of catalysts that can enable the widespread use of molecular oxygen as an oxidant for organic synthesis. This thesis presents two new classes of reactions between metal complexes and molecular oxygen. Neutral five-coordinate Pt complexes were tested for reactivity in the presence of molecular oxygen. In arene solution, the complexes (t̳B̳u̳̳M̳e̳2̳ nacnac)PtMe3 (1, t̳̳B̳u̳M̳e̳2̳ nacnac- = [((4-tBu-2,6-Me2C6H2)NC(CH3))2CH]-), (M̳e̳3̳ Me-nacnac)PtMe3 (2, M̳e̳3̳ Me-nacnac- = [((2,4,6-Me3C6H2)NC(CH3))2CCH3]-), and (t̳B̳u̳2̳ PyPyr)PtMe3 (3, t̳B̳u̳2̳ PyPyr- = 3,5-di-tert-butyl-2-(2-pyridyl)pyrrolide) reacted immediately with oxygen to form peroxo species in which two oxygen atoms bridge between the metal center and a carbon atom in the ligand backbone. In contrast, no reaction between ( i̳P̳r̳2̳ AnIm)PtMe3 (4a, i̳P̳r̳2̳ AnIm− = [o- C66H4-{N(C6H3 i Pr2)}(CH=NC6H3 i Pr2)]−) or (M̳e̳3̳ AnIm)PtMe3 (4b, M̳e̳̳3̳ AnIm− = [o-C6H4- {N(C6H2Me3)}(CH=NC6H2Me3)]−) and oxygen was observed. As activation of oxygen by five- coordinate PtIV species was found to involve cooperation between the metal center and the ligand, the ability of the ligand to participate in the oxygen binding appears to be a vital component. Oxygen atom transfer reactions of the novel peroxo species are also presented. In a separate study, an unusual reaction involving the activation of both molecular oxygen and a C-H bond at the same metal center was investigated. Pd(P(Ar)(tBu)2)2 (15, Ar = naphthyl) was found to react with molecular oxygen at room temperature in arene solvent to form a hydroxide dimer in which one equivalent of phosphine per Pd was lost and the remaining phosphine was cyclometalated through the naphthyl ring. At low temperature, two intermediates were observed. The nature of these intermediates suggests a mechanism involving initial reaction of Pd(P(Ar) (tBu)2)2 with O2 followed by the C-H activation step. In a final chapter unrelated to oxygen reactivity, the generation and characterization of a gold III̳-alkene complex by NMR and X-ray crystallography is presented. Such species have been proposed as intermediates in catalytic reactions but until recently none had been observed.

Book D10 Palladium and Platinum Complexes with Alkene and Diimine Ligands

Download or read book D10 Palladium and Platinum Complexes with Alkene and Diimine Ligands written by Janet Lynne Whittemore and published by . This book was released on 1990 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis and Reactivity of Unusual Palladium II Complexes Supported by a Diarylamido BIS Phosphine PNP Pincer Ligand

Download or read book Synthesis and Reactivity of Unusual Palladium II Complexes Supported by a Diarylamido BIS Phosphine PNP Pincer Ligand written by Rafael Huacuja and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation discusses the synthesis and reactivity of divalent palladium complexes supported by diarylamido bis-phosphine pincer ligands (PNP). The PNP is a tridentate pincer type ligand which typically adopts meridional type coordination. The rigidity and tight coordination of the PNP ligand provides the unique opportunity to study the coordination of ligands such as O2 and C2H4 to a single coordination site on palladium, or the reactivity of a single empty coordination site trans to a weak trans-influencing ligand such as diarylamido. Irradiation of [(^(F)PNP^(iPr))Pd-]2 under an atmosphere of dioxygen irreversibly produces a mixture of a monohapto palladium(II) superoxide ((^(F)PNP^(iPr))PdO2) and a palladium micro-peroxide ([(^(F)PNP^(iPr))PdO-]2). Under photolytic conditions these two complexes are in equilibrium with each other. (^(F)PNP^(iPr))PdO2, an open-shell paramagnetic species, was characterized by a combination of single-crystal X-ray crystallography, EPR, and 19F NMR spectroscopies. In addition, irradiation of [(PNP)Pd-]2 under an atmosphere of C2H4 produces a mixture of [(PNP)Pd-]2 and a ethylene-bridged dinuclear palladium complex ([(PNP)Pd-CH2-]2). If the ethylene headspace is removed, and [(PNP)Pd-CH2-]2 is irradiated it is completely converted to [(PNP)Pd-]2. This suggests that in the presence of ethylene these two complexes are in photolytic equilibrium with each other. In addition, this dissertation will also discuss the synthesis and reactivity of [(PNPR)Pd]+ (R = ^(i)Pr, ^(t)Bu) cations. [(^(F)PNP^(iPr))Pd]+ cations are highly electrophilic complexes that are able to coordinate Lewis bases such as THF, H2O, and even extremely poor Lewis bases such as toluene and benzene. In addition, irradiation of [(^(F)PNP^(iPr))Pd]+ cations in bromobenzene induces the abstraction of a bromine atom from bromobenzene, consistent with a metalloradical species. Addition of dioxygen to [(^(F)PNP^(iPr))Pd]+ cations generates a paramagnetic, cationic [eta]1 superoxide. In non-halogenated arene solvents [(^(F)PNP^(iPr))Pd]+ cations undergo a highly unusual photo-induced isomerization of the isopropyl groups on the supporting phosphines to n-propyl. This unprecedented isomerization is believed to occur via C-P bond cleavage and is driven by the decrease in sterics around the metal, which allows for the facilitated coordination of the arene solvent. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152457

Book Synthesis and Reactivity of Palladium Complexes that Contain Redox active Verdazyl Ligands

Download or read book Synthesis and Reactivity of Palladium Complexes that Contain Redox active Verdazyl Ligands written by Corey A. Sanz and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the synthesis, characterization and reactivity of a series of palladium complexes that contain redox-active verdazyl ligands. This work was motivated by the possibility of discovering new and interesting reactivity that may eventually lead to the development of new chemical reactions. A bidentate verdazyl radical ligand that contains an aryl phosphine was synthesized. Reaction of this ligand with (PhCN)2PdCl2 yielded a square planar (verdazyl)PdCl2 complex. Structural and spectroscopic data suggest that this compound consists of a ligand-centered radical coordinated to a Pd(II) center. The radical complex was chemically reduced by one-electron to generate a binuclear chloride-bridged [(verdazyl)PdCl]2 complex. In this reduced complex, both metals were still Pd(II) and the verdazyl ligand was determined to be in its singly reduced, monoanionic charge state. The original radical PdCl2 complex could be regenerated via one-electron oxidation of the reduced complex using PhICl2. The verdazyl ligands in the reduced complex could also be reversibly protonated to generate "leuco" verdazyl complex (verdazyl-H)PdCl2. Reaction of the radical (verdazyl)PdCl2 complex with water triggers a ligand-centered redox disproportionation reaction. A series of bis(verdazyl) palladium complexes were synthesized using a bidentate pyridine-substituted verdazyl ligand. Reaction of two equivalents of radical ligand with (CH3CN)4Pd2+ yielded a (verdazyl)2Pd(solvent)2+ complex (solvent = CH3CN or DMSO). In this complex, one verdazyl radical ligand chelates to palladium and the other binds as a monodentate ligand. Two-electron reduction of this complex generated a (verdazyl)2Pd complex in which two monoanionic verdazyl ligands are bound to a central Pd(II) ion. This reduced complex could also be made via reaction of 0.5 equivalents of Pd(0)2(dba)3 with two equivalents of radical ligand. In this reaction, the metal is oxidized by two electrons and each ligand is reduced by a single electron. Two-electron oxidation of the reduced complex in the presence of DMSO yielded the original bis(radical)complex, (verdazyl)2Pd(DMSO)2+. Chlorination of the reduced complex using one equivalent of PhICl2 (two-electron oxidation) resulted in dissociation of one verdazyl ligand to afford a 1:1 mixture of free verdazyl : (verdazyl)PdCl2, in which both of the verdazyls are neutral radicals. Reaction of the reduced complex with 0.5 equivalents of PhICl2 (one-electron oxidation) yielded a (verdazyl)2PdCl complex that contained a bidentate reduced verdazyl ligand and a monodentate radical ligand. All three of the oxidation reactions described above adhere to ligand-centered redox chemistry. Reaction of the reduced (verdazyl)2Pd complex with excess HCl resulted in protonation of both the anionic verdazyl ring and the pyridyl group to generate a leuco/pyridinium tetrachloropalladate salt, (verdazyl-H2)2(PdCl4). The protonated salt could be converted back to the original (verdazyl)2Pd complex by deprotonation with water. Palladium complexes of a tridentate NNN-chelating verdazyl ligand were prepared and their redox chemistry was explored. Reaction of the radical ligand with (CH3CN)4Pd2+ yielded radical complex (verdazyl)Pd(NCCH3)2+. The tridentate ligand was also prepared in its reduced, leuco form (verdazyl-H). Reaction of the leuco verdazyl with (CH3CN)2PdCl2 generated HCl and a (verdazyl)PdCl complex in which the ligand is in its monoanionic charge state. The reduced (verdazyl)PdCl complex was reacted with AgBF4 to afford (verdazyl)Pd(NCCH3)+ via chloride abstraction; the verdazyl remained in its reduced charge state following the reaction. Both reduced complexes (chloro and acetonitrile) were oxidized by a single electron to afford the corresponding radical complexes. These radical complexes could be reduced by a single electron to regenerate the original reduced complexes. Like the previous two projects, all of the redox chemistry was ligand-centered. The reactivity of these complexes with primary amines was also explored. Reaction of radical complex (verdazyl)Pd(NCCH3)2+ with n-butylamine resulted in one-electron reduction of the verdazyl ligand. We were unable to determine the mechanism of the reaction, but the reactivity that was observed demonstrates the potential for verdazyl-palladium complexes to be used in the design of new radical reactions.

Book Palladium Complexes with Germylene Ligands

Download or read book Palladium Complexes with Germylene Ligands written by Zuzanna Teresa Cygan and published by . This book was released on 2004 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis Characterization and Redox Studies of Platinum and Palladium Complexes with Mer coordinating Ligands

Download or read book Synthesis Characterization and Redox Studies of Platinum and Palladium Complexes with Mer coordinating Ligands written by Seher Kuyuldar Tastan and published by . This book was released on 2009 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic, structural, spectroscopic, and redox studies of platinum(II) and palladium(II) compounds with mer-coordinating ligands have been undertaken in an effort to better understand the role of the metal and the ligands in controlling d^6/d^8 electron-transfer reactions. A series of Pd(pip2NCN)X (pip2NCNH=1,3-bis(piperdylmethyl)benzene) and [Pd(pip2NNN)X]X (X=Cl, Br, I) (pip2NNN=2,6- bis(piperdyl-methyl)pyridine) complexes are reported. Electronic spectra are consistent with stabilization of ligand-to-metal-charge-transfer states as the ancillary ligand is varied along the ClBr

Book The Synthesis and Luminescence Properties of Platinum Palladium and Iridium Complexes Featuring Multidentate Ligands

Download or read book The Synthesis and Luminescence Properties of Platinum Palladium and Iridium Complexes Featuring Multidentate Ligands written by Melissa Teresa Walden and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: