Download or read book Design and Synthesis of Metal Phosphine Complexes of Palladium ii and Gold i with Various Receptor Ligands for Ion Controlled Or Photoresponsive Host Guest Chemistry written by Hau-San Tang and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Design and Synthesis of Metal Phosphine Complexes of Palladium(II) and Gold(I) With Various Receptor Ligands for Ion-controlled or Photoresponsive Host-guest Chemistry" by Hau-san, Tang, 鄧巧珊, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled DESIGN AND SYNTHESIS OF METAL PHOSPHINE COMPLEXES OF PALLADIUM(II) AND GOLD(I) WITH VARIOUS RECEPTOR LIGANDS FOR ION-CONTROLLED OR PHOTORESPONSIVE HOST-GUEST CHEMISTRY Submitted by Tang Hau San for the Degree of Doctor of Philosophy at The University of Hong Kong in August 2006 A series of palladium(II) phosphine complexes containing different receptor sites, [Pd(PPh R) Cl] [R = C H NHCOCH, C H N(CH )COCH, 2 2 2 6 4 3 6 4 3 3 C HNHCONHPh, C HNHCOPyr and C H NHCO(CH )Pyr] have been 6 4 6 4 6 4 2 3 prepared. Two X-ray crystal structures have been determined, in which one of the crystal structures showed hydrogen bonding interactions between the amide protons and the Cl ions with distances of ca. 2.466 A. The photophysical properties of these complexes have been studied and their emission origins were elucidated. The binding properties of the complexes towards anions have 1 31 been studied by H NMR, P NMR, UV-vis and emission spectrophotometry, in which drastic changes in the ratio of trans to cis isomers upon addition of 31 anions were observed in the P NMR titration studies. The present ion-induced conformational change involving a trans-cis isomerization of the square-planar palladium(II) complex via the binding of anions to amide or urea functionalities through hydrogen bonding interactions represents a new class of ion-controlled switching devices based on transition metal systems. A series of gold(I) alkynyl phosphine complexes containing azobenzene or stilbene functionalities, [{Au(PPh )} (C≡C-L-C≡C)] and [Au (P DEGREESP) (C≡C-L- 3 2 4 2 C≡C) ] [L = C H -N=N-C H or C H -CH=CH-C H; P DEGREESP = dppm, dcpm, 2 6 4 6 4 6 4 6 4 Ph PN(C H F-p)PPh, Ph PN( Pr)PPh, Ph PN(C H )PPh] have been 2 6 4 2 2 2 2 14 29 2 synthesized and characterized. The X-ray crystal structure of [Au (dppm) (C≡C- 4 2 L-C≡C) ] revealed that the two azobenzene ligands in the tetranuclear complex adopted a trans disposition with the presence of short intramolecular Au Au contacts. The azobenzene-containing gold(I) complexes showed emissions both in dichloromethane solution at room temperature and in 77 K glass, which were assigned as a metal-perturbed intraligand (IL) origin mainly derived from the π-π*(C≡C) states with some mixing of a π-π* character of the azo unit. On the other hand, the emissive origin of the stilbene-containing gold(I) complexes was assigned as derived from the π-π* excited state of the stilbene moiety with some mixing of the alkynyl units, and probably mixed with σ(Au-P) → π*(C≡C) excited state in the solid states. The photoisomerization properties of the dinuclear and tetranuclear complexes have been studied, in which a tetranuclear macrocyclic gold(I) alkynyl phosphine complex was demonstrated to function as a dual input molecular logic with photoswitching behaviour that could be controlled by addition or removal of silver(I). In addition, several gold(I) complexes with different crown ether pendants including the mercapto-azacrown ether-containing complexes, [Au (P DEGREESP)(S-A15C5) ] [P DEGREESP = dppm, dcpm] and the mononuclear gold(I) alkynyl 2 2 complexes, [Au(PPh )(C≡CR)] [R = B15C5, B15S5], and dinuclear gold(I) complexes with oligo(ethylene oxide) linkages, [{(Ph P)

Download or read book Design and Synthesis of Metal Phosphine Complexes of Palladium II and Gold I with Various Receptor Ligands for Ion controlled Or Photoresponsive Host guest Chemistry written by Hau-san Tang and published by . This book was released on 2006 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and Synthesis of Phosphine Ligands for Palladium catalyzed Coupling Reactions written by William Scott Brown and published by . This book was released on 2009 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis and design of new phosphines is a continuing area of interest. In designing new phosphines there are a number of design features that need be considered. For palladium catalyzed coupling reactions, sterically demanding and electron releasing ligands are generally most effective in promoting the reaction. In evaluating the hydrophobic phosphines utilized in the Suzuki coupling, the neopentyl derivatives of TTBP (tri-tert-butylphosphine) were investigated. The effect of the addition of a neopentyl group increases the cone angle and impacts the electron donation by decreasing it relative to TTBP. The application in Suzuki coupling shows that a palladium catalyst with a neopentyl phosphine ligand demonstrates good to excellent yields with aryl bromides at room temperature. In the design of new phosphines, building in polar groups generates the ability to take advantage of using water as a solvent or co-solvent. The synthesis of the water soluble ligands DTBPPS (di-tert-butylphosphoniumpropane sulfonate) and DAPPS (di-adamantylphosphoniumpropane sulfonate) led to their testing in Sonogashira and Suzuki coupling reactions. Both ligands give catalysts that show good to excellent conversion of aryl bromides to products at room temperature. For aryl chlorides elevated temperatures are required. In expanding the water-soluble ligands into other palladium coupling reactions, DAPPS was developed in the carbonylation of aryl bromides. The palladium/DAPPS-catalyzed carbonylation coupling reactions show good to excellent conversion of aryl bromides to carbonylated products. This is the first example of a water-soluble alkylphosphine promoting carbonylation of an aryl bromide.

Download or read book Gold i and Gold ii Phosphine Complexes Exhibiting Weak Aui Aui Interactions and Unsupported Auii Auii Bonds written by Chi-Kwan Li and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Gold(I) and Gold(II) Phosphine Complexes Exhibiting Weak AuI... AuI Interactions and Unsupported AuII-AuII Bonds: Syntheses, Spectroscopy, Host-guest Chemistry and Reactivity Studies" by Chi-kwan, Li, 李志君, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3124333 Subjects: Gold - Analysis Gold compounds Metal complexes - Synthesis

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:

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.

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

Download or read book Square planar Dichloro Palladium Complexes with i trans i configurated Phosphine Ligands Avoiding i ortho i metallation Ligand Design Complex Synthesis Molecular Structure and Catalytic Potential for Suzuki Cross coupling Reactions written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of D 10 Metal Complexes Utilizing Bipyridine and Binaphthol Based Phosphine Ligands written by and published by . This book was released on 2005 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Also described in this work is the synthesis and characterization of a new class of phosphine ligands based on 1,1'-binaphthol. The ligand was used in the synthesis of several metal complexes including a gold metallocryptand that contains four Tl(I) ions. The structure of [Au2Tl4(P 2binol)] (P2binol = 3,3'-bis(diphenylphosphino)-1,1'-bi-2-naphthol) shows that the Au(I)-Tl(I) distances are long (average 3.38 A), indicating that little or no metal-metal interaction is present. The core is surrounded by three more Tl(I) atoms held in the assembly by the oxygen atoms of the binaphthol ligand. The complex is also highly luminescent in solution (lambda max = 514 nm, lambdaex = 470 nm). The possibility of using the new binaphthol ligands in encapsulating lanthanide ions is also reported.

Download or read book Synthesis and Application of Air Stable Secondary Phosphine Oxide Oxime and Amine Phosphine Palladium II Complexes in Transfer Hydrogenation and Cross Coupling Reactions written by Jason E. Bara and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis plays an important role in industry as over 90% of chemical processes involve catalysts in at least one step. Historically, heterogeneous catalysis has been more commonly employed in industry as these systems tend to be more economically friendly and environmentally benign. However, improved procedures for homogeneous catalysis using organocatalysts and organometallic compounds has generated increased interest in homogeneous systems. Organometallic compounds offer higher specific activities and selectivity in comparison to traditional heterogeneous systems. These qualities make homogeneous catalysis particularly attractive for the production of fine chemicals, pharmaceuticals, and natural products. Ligand design is critical for the development of homogeneous catalysts. For late-transition-metal-catalyzed cross-coupling reactions that rely on C-X or C-H oxidative addition, strongly electron-donating and sterically demanding ligands afford the most efficient systems. Several privileged classes of ligands have been identified and employed in palladium-catalyzed reactions. These systems are believed to promote their respective reactions through a monoligated palladium(0) species. Our work focused on the development of precatalysts with an established 1:1 L:Pd ratio. Specifically, we were interested in the synthesis of palladium(II) precatalysts with the general formula (R3P)Pd(amine)Cl2, using di-tert-butylneopentylphosphine and trineopentylphosphine. Under optimized conditions, the precatalysts were effective for the Buchwald-Hartwig amination of aryl bromides and aryl chlorides. We discovered that the identity of the amine ligand significantly impacts catalyst efficiency with linear primary alkyl amines providing the most active catalysts. A comparison study between the air-stable precatalysts and in situ generated catalysts showed improved activity for the precatalysts. Typically, the aforementioned privileged classes of ligands behave as spectators during the bond activation process. However, ligands containing functional groups that introduce acidic/basic sites proximal to the metal center can participate through acid-base interactions with the substrates. Multifunctional ligands have proven to be efficient in numerous transition-metal-catalyzed processes. We focused on synthesizing secondary phosphine oxide and oxime ligands that contain a basic hydroxyl group(s) upon complexation. The synthesis of oxime-derived palladacycles was facile and efficient. These catalysts efficiently facilitated the transfer hydrogenation of benzophenone. The active species is believed to be a three- or four-atom palladium cluster resulting from decomposition of the palladium-oxime complex.

Download or read book Design of Precatalysts and Phosphine Ligands for Pd catalyzed Transformations written by Bryan Taylor Ingoglia and published by . This book was released on 2019 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work described in this thesis pertains to the formation of carbon-heteroatom bonds facilitated by palladium catalysts supported by bulky phosphine ligands. The first chapter is a summary of how biaryl monophosphine ligands have been used for carbon-heteroatom bond formations, including a ligand selection guide. The second chapter demonstrates how phosphinesupported Pd(II) oxidative addition complexes can be used as precatalysts in a variety of cross-coupling reactions. The third chapter presents a systematic study of the ligand architecture in an effort to rationally design new ligands capable of facilitating the challenging C-F reductive elimination from Pd(II). The fourth chapter highlights a structurally interesting side-product that resulted during ligand synthesis. Chapter 1: Biaryl Monophosphine Ligands in Palladium-Catalyzed C-N Coupling: An Updated User's Guide Over the past three decades, Pd-catalyzed cross-coupling reactions have become a mainstay of organic synthesis. In particular, catalysts derived from biaryl monophosphines have shown wide utility in forming C-N bonds under mild reaction conditions. This work summarizes a variety of C-N cross-coupling reactions using biaryl monophosphines as supporting ligands, with the goal of directing synthetic chemists toward the ligands and conditions best suited for a particular coupling. Chapter 2. Oxidative Addition Complexes as Precatalysts for Cross-Coupling Reactions Requiring Extremely Bulky Biarylphosphine Ligands. Palladium-based oxidative addition complexes were found to be effective precatalysts for C-N, C-O, and C-F cross-coupling reactions with a variety of aromatic electrophiles. These Pd(II) complexes are easily prepared and offer a convenient alternative to previously developed classes of precatalysts as they can be formed even with extremely large phosphine ligands, for which palladacycle-based precatalysts do not readily form. The complexes were found to be stable to long-term storage under ambient conditions. Chapter 3. Structure-Activity Relationship of Phosphine Ligands for the Fluorination of Five-membered Heteroaromatic Compounds Palladium catalysts supported by bulky dialkyl triaryl monophosphine ligands have been shown to promote the coupling of metal fluorides with (hetero)aryl bromides and triflates in good yield. A limitation of this methodology is the use of five-membered heteroaryl bromides, as the reductive elimination is more challenging due to the smaller size and electron-rich nature of the aryl electrophiles. In order to understand which structural features of the ancillary ligand are critical to facilitating the desired transformation, the ligand backbone was systematically varied and the initial rate of fluorination was monitored. These studies revealed that substitution at the 2" and 6" positions of the ligand scaffold has a dramatic impact on the reaction rate. As a result of these studies, new ligands were proposed which may be better able to accelerate the fluorination reaction. Chapter 4: Discovery of a Sterically Encumbered Hexasubstituted Arene through the Pdmediated Dearomative Rearrangement of Biaryl Monophosphine Ligands A key feature of the Pd-catalyzed aromatic fluorination reaction is the presence of the aryl group at the 3' position of the ligand backbone. It has been shown that supporting ligands lacking substitution at this position can be modified through a dearomative rearrangement, which incorporates one catalytic equivalent of the aryl electrophile into the ligand backbone when very bulky biarylphosphines are used. In Chapter 3, it was demonstrated that this rearrangement reaction is useful for rapidly accessing a variety of dialkyl triaryl monophosphine derivatives. During these studies, it was noted that for electron-rich aryl groups, this arylation occurred twice to form an unusual sterically congested hexasubstituted arene. X-ray crystallographic data indicates that the fully substituted aromatic ring is not planar.

Download or read book The Relationship Between Structure and Interaction in Noble Metal Phosphine Complexes written by Daniel Thomas Walters and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text includes multiple interconnected projects that explore the chemistry of gold(I) phosphine complexes for purposes of elucidating the interactions of monovalent gold centers both with and without aurophilic attractions. These studies expressly focus upon the solid state properties, where structural determination via X-ray crystallography is key. The first chapter focuses on the series of complexes Au2([mu]-dppe)X2 (dppe is 1,2-bis(diphenylphosphino)ethane, X = Cl, Br, I) and Au2([mu]-dcpe)X2 (where dcpe is 1,2-bis(dicyclohexylphosphino)ethane). Previous work had focused on luminescent characteristics of similar complexes, but the phosphine ligands contained fluorophoric phenyl moieties that could be identified as contributors to this phenomenon. In addition, prior comparable studies had similar ligands that displayed a propensity towards polymeric or pseudo-polymeric structures, and the increased steric bulk of cyclohexyl groups was utilized to inhibit the formation of such aggregation. This study clarifies and infers the innocent nature of the dppe ligand with regards to luminescence displayed in monovalent gold complexes containing aurophilic interactions, allowing the emissions to be more confidently attributed to the metal-metal interactions. The second chapter focuses on the synthesis and interconversion of a series of complexes comprised of triphos (bis(2-diphenylphosphinoethyl)phenylphosphine), bridging monovalent gold atoms, and non-coordinating anions. Helicate ([Au3(Triphos)2]3+) systems may form monomeric units, or dimerize with bridging chloride anions, but do not display tendencies towards polymeric formations. Gold box systems ([Au6(Triphos)4Cl]5+) may form with EF6− type anions, with a complex packing structure displaying a fascinating dependency upon cavity occupancy on the molecule's surface as well as its interior. Each of these systems display distinct luminescence and these may be readily interconverted through mechanical stimuli or a recrystallization that is sensitive to specific solvent systems. The third chapter focuses on a series of complexes analogous to those in the second chapter, but utilizing bromide ions in the places previously occupied by chloride. The same helicate,bridged dimer, and gold box interconversions are observed, with the additional possibility of a second encapsulated bromide anion. These systems display much more selective luminescence with greater diversity, and mechanical stimuli resulted in the observation of transformation through negative mechanochromism where the previous case was positive mechanochromism. The box moieties and their transitions appear to be dictated by localized interactions with anions and solvent resting within nested formations of phenyl rings. Within these studies, the box has been identified as a viable luminescent molecular container for small anions with the assistance of appropriately sized solvent molecules (e.g. toluene), but the di-bromo box system implies a greater variation for content size. A system of such extreme lability and fluxionality may have excellent potential as a selective capture agent, especially with such simplistic conformation away from a container room temperature mechanical grinding at room temperature or dissolving in a solvent that inhibits box formation such as methanol.

Download or read book Transition metal Complexes Containing Phosphorus Ligands written by Naseer Ahmad and published by . This book was released on 1973 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition metal complexes containing phosphorus ligands written by and published by . This book was released on 1973 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Reactivity of Polyfunctional Phosphorus Ligands and Their Transition Metal Complexes written by Shuanming Zhang and published by . This book was released on 2011 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of P,N chelating ligands and their transition metals complexes has become increasingly attractive in the last few years owing to their intrinsic structural properties and broad applications. Such heterofunctional ligands possess a hard nitrogen donor with a soft phosphorus donor leading to considerable chemical and structural diversity and may generate hemilabile systems endowed with enhanced reactivity.1k, 1m We are particularly interested in thiazoline- and oxazoline-based phosphine systems, which are often active in catalytic ethylene oligomerisation. We are also interested in Pt(II) complexes derived from P,P functional ligands derived from Ph2PCH2PPh2 (dppm), which exhibit interesting luminescence properties.

Download or read book Supramolecular Chemistry in the 3rd Millennium written by Catherine E. Housecroft and published by MDPI. This book was released on 2021-08-18 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue is one of the first for the new MDPI flagship journal Chemistry (ISSN 2624-8549) which has a broad remit for publishing original research in all areas of chemistry. The theme of this issue is Supramolecular Chemistry in the 3rd Millennium and I am sure that this topic will attract many exciting contributions. We chose this topic because it encompasses the unity of contemporary pluridisciplinary science, in which organic, inorganic, physical and theoretical chemists work together with molecular biologists and physicists to develop a systems-level understanding of molecular interactions. The description of supramolecular chemistry as 'chemistry beyond the molecule' (Jean-Marie Lehn, Nobel Lecture and Gautam R. Desiraju, Nature, 2001, 412, 397) addresses the wide variety of weak, non-covalent interactions that are the basis for the assembly of supramolecular architectures, molecular receptors and molecular recognition, programed molecular systems, dynamic combinatorial libraries, coordination networks and functional supramolecular materials. We welcome submissions from all disciplines involved in this exciting and evolving area of science.