Synthesis, Characterization and Coordination Chemistry of Pincer Ligands Based on (benzannulated) Pyridines

Synthesis, Characterization and Coordination Chemistry of Pincer Ligands Based on (benzannulated) Pyridines
Author: Jason Braun
Publisher:
Total Pages: 0
Release: 2020
Genre:
ISBN:

Download Synthesis, Characterization and Coordination Chemistry of Pincer Ligands Based on (benzannulated) Pyridines Book in PDF, Epub and Kindle

The idea of 'non-innocent' ligands is that the site of chemical or redox activity on a coordination complex may not be solely limited to the central atom. Ligands may participate either by themselves or in cooperation with a central atom to facilitate electron-transfer and/or chemical reactivity in a more active fashion than in a typical coordination complex. Each of the projects explored in this thesis include the common theme of pyridine-based pincer-type ligands, their coordination to late transition metals and main group elements, and how the reactivity and properties of these complexes involves both the ligand and the ligated element. To do so, a comprehensive investigation of the electronic structure of complexes supported by pincer-type, 'NNN' ligands is also described. Diiminepyridine ligands tend to actively participate in the chemistry of their complexes. Taking advantage of these non-innocent ligands has allowed for the stabilization of unusual oxidation states of transition metal complexes as well as the facilitation of chemical transformations with metals unable to do so using spectator ligands. Pseudo-octahedral iron complexes of these ligands exhibit multiple reversible reductions and are shown to be viable candidates as anolytes for redox flow battery applications. In synthesizing these, a synthetic scheme to prepare these ligands with electron withdrawing groups on the flanking aryl groups was developed, opening up the chemical space for these new ligands in the already well-established field of diiminepyridine ligand chemistry. In addition, bulky analogues engender stabilization of phosphorus complexes in the +1 and +3 oxidations states, not seen before with traditional diiminepyridine ligands. The synthetic route to diarlyamido ligands comprised of flanking quinoline (2,3-benzopyridine) and phenanthridine (3,4-benzoquinoline) donors has also been developed and the coordination of these monoanionic ligands to a variety of late transition metals and main group elements was explored. Several aspects of this ligand can be deemed non-innocent and will be highlighted throughout the course of this thesis. We see an unusual electronic environment of pseudo-octahedral iron complexes of these ligands that exhibit record length charge-transfer excited states and panchromatic absorption. Exchanging the central metal can bring about mixed-valent species upon oxidation evidenced by strong absorption in the near infrared region of the electromagnetic spectrum that significantly depends on metal-ligand orbital overlap.

Pincer Compounds

Pincer Compounds
Author: David Morales-Morales
Publisher: Elsevier
Total Pages: 756
Release: 2018-04-11
Genre: Science
ISBN: 0128129328

Download Pincer Compounds Book in PDF, Epub and Kindle

Pincer Compounds: Chemistry and Applications offers valuable state-of-the-art coverage highlighting highly active areas of research—from mechanistic work to synthesis and characterization. The book focuses on small molecule activation chemistry (particularly H2 and hydrogenation), earth abundant metals (such as Fe), actinides, carbene-pincers, chiral catalysis, and alternative solvent usage. The book covers the current state of the field, featuring chapters from renowned contributors, covering four continents and ranging from still-active pioneers to new names emerging as creative strong contributors to this fascinating and promising area. Over a decade since the publication of Morales-Morales and Jensen’s The Chemistry of Pincer Compounds (Elsevier 2007), research in this unique area has flourished, finding a plethora of applications in almost every single branch of chemistry—from their traditional application as very robust and active catalysts all the way to potential biological and pharmaceutical applications. Describes the chemistry and applications of this important class of organometallic and coordination compounds Includes contributions from global leaders in the field, featuring pioneers in the area as well as emerging experts conducting exciting research on pincer complexes Highlights areas of promising and active research, including small molecule activation, earth abundant metals, and actinide chemistry

The Chemistry of Pincer Compounds

The Chemistry of Pincer Compounds
Author: David Morales-Morales
Publisher: Elsevier
Total Pages: 467
Release: 2011-08-11
Genre: Science
ISBN: 0080545157

Download The Chemistry of Pincer Compounds Book in PDF, Epub and Kindle

Pincer complexes are formed by the binding of a chemical structure to a metal atom with at least one carbon-metal bond. Usually the metal atom has three bonds to a chemical backbone, enclosing the atom like a pincer. The resulting structure protects the metal atom and gives it unique properties.The last decade has witnessed the continuous growth in the development of pincer complexes. These species have passed from being curiosity compounds to chemical chameleons able to perform a wide variety of applications. Their unique metal bound structures provide some of the most active catalysts yet known for organic transformations involving the activation of bonds. The Chemistry of Pincer Compounds details use of pincer compounds including homogeneous catalysis, enantioselective organic transformations, the activation of strong bonds, the biological importance of pincer compounds as potential therapeutic or pharmaceutical agents, dendrimeric and supported materials. * Describes the chemistry and applications of this important class of organometallic and coordination compounds* Covers the areas in which pincer complexes have had an impact* Includes information on more recent and interesting pincer compounds not just those that are well-known

Proton-responsive Pyridine-based Ligands

Proton-responsive Pyridine-based Ligands
Author: Sandra Yvette Boer
Publisher:
Total Pages: 163
Release: 2016
Genre:
ISBN:

Download Proton-responsive Pyridine-based Ligands Book in PDF, Epub and Kindle

Catalysts are in dispensable for society as they are applied in the majority of industrial processes. Catalysts can increase the rate at which a reaction proceeds, but can also selectively produce only one product, thereby preventing side reactions and the production of side products or waste, resulting in more efficient, atom-economical and environmentally benign processes. In homogeneous catalysis, the catalyst often consists of a transition metal that is surrounded by ligands. Reactive or proton-responsive ligands may be envisioned to operate in a synergistic way with the metal to facilitate a chemical process. This concept of metal-ligand cooperation (MLC) has gained a lot of interest over the past decade and is currently a rapidly expanding field of homogeneous catalysis. The research described in this thesis is focused on the development of new metal complexes bearing different proton-responsive ligand systems. More specifically, several bidentate and tridentate types of pyridine-based ligands are described, based on phosphinomethylpyridines, pyridones and pyrazoles. They all exhibit a cooperative character in their own specific way. The coordination to mainly 2nd row late-transition metals (Ru, Rh, and Pd) is successfully demonstrated, along with the behavior of their bifunctional character. Application in several catalytic transformations is studied, including various dehydrogenative coupling reactions and the intramolecular hydroamination of aminoalkenes and -alkynes.

Synthesis and Reactivity of the First Pincer-type Ligands Containing Heterocyclic Thiones and Selones

Synthesis and Reactivity of the First Pincer-type Ligands Containing Heterocyclic Thiones and Selones
Author: Tingting Lu
Publisher:
Total Pages: 132
Release: 2010
Genre:
ISBN:

Download Synthesis and Reactivity of the First Pincer-type Ligands Containing Heterocyclic Thiones and Selones Book in PDF, Epub and Kindle

The bis(mercaptoimidazolyl)methanes (BmmR) and bis(mercaptoimidazolyl)xylenes (BmxR) (R = Me, Bu') are two families of ligands that offer strong electron-donating sulfur groups. They have been used to prepare a variety of main group and transition group metal complexes, including synthetic analogues of the copper protein methanobactin. Seeking to develop the coordination chemistry of new pincer-type ligands, we describe here the synthesis and characterization of the first pincer-type ligands containing heterocyclic thiones and selones, namely bis(mercaptoimidazolyl)lutidine (BmlutMe) and bis(selenoimidazolyl)lutidine (BselutMe). These two chelating agents feature two thione or selone donor groups as substituents on a 2,6-lutidine core, thereby providing [NS2] or [NSe2] donor sets, respectively. Initial reactivity studies with the new ligands have led to the isolation of several metal complexes, including derivatives of manganese(l), rhenium(l), cobalt(ll), copper(l), cadmium(ll), mercury(ll), and bismuth(lll). The complete characterization of these complexes will be described in this thesis.

Scorpionates: The Coordination Chemistry Of Polypyrazolylborate Ligands

Scorpionates: The Coordination Chemistry Of Polypyrazolylborate Ligands
Author: Swiatoslaw Trofimenko
Publisher: World Scientific
Total Pages: 294
Release: 1999-08-16
Genre: Science
ISBN: 1783261994

Download Scorpionates: The Coordination Chemistry Of Polypyrazolylborate Ligands Book in PDF, Epub and Kindle

This book deals with polypyrazolylborates (scorpionates), a class of ligands known since 1966, but becoming rapidly popular with inorganic, organometallic and coordination chemists since 1986, because of their versatility and user-friendliness. They can be readily modified sterically and electronically through appropriate substitution on the pyrazole ring and on boron, and have led to a number of firsts in coordination chemistry (first stable CuCO complex, first monomeric MgR complex, and many other such firsts). Their denticity can range from two to four, their “Bite” can be adjusted, and additional coordinating sites can be added to the pyrazolyl rings. Over 170 different scorpionate ligands are known today, and some are published for the first time in this book.The author, Swiatoslaw Trofimenko, discovered and developed this ligand system and has written several reviews on the subject. The book is intended as a reference work, placing at the researcher's command practically all of the over 1500 references on the subject up, and into 1999, organized both according to the ligand type and according to the metal or metalloid being coordinated. It acquaints the reader with the special features of this ligand system and permits an assessment of what has been done in a given sub-area, and of which areas remain relatively unexplored. It presents procedures for ligand synthesis, and also covers their use in catalysis and in the modelling of biologically active substances.

Organometallic Pincer Chemistry

Organometallic Pincer Chemistry
Author: Gerard van Koten
Publisher: Springer
Total Pages: 0
Release: 2014-10-15
Genre: Science
ISBN: 9783642438493

Download Organometallic Pincer Chemistry Book in PDF, Epub and Kindle

Gerard van Koten: The Mono-anionic ECE-Pincer Ligand - a Versatile Privileged Ligand Platform: General Considerations.- Elena Poverenov, David Milstein: Non-Innocent Behavior of PCP and PCN Pincer Ligands of Late Metal Complexes.- Dean M. Roddick: Tuning of PCP Pincer Ligand Electronic and Steric Properties.- Gemma R. Freeman, J. A. Gareth Williams: Metal Complexes of Pincer Ligands: Excited States, Photochemistry, and Luminescence.- Davit Zargarian, Annie Castonguay, Denis M. Spasyuk: ECE-Type Pincer Complexes of Nickel.- Roman Jambor and Libor Dostál: The Chemistry of Pincer Complexes of 13 - 15 Main Group Elements.- Kálmán J. Szabo: Pincer Complexes as Catalysts in Organic Chemistry.- Jun-ichi Ito and Hisao Nishiyama: Optically Active Bis(oxazolinyl)phenyl Metal Complexes as Multi-potent Catalysts.- Anthony St. John, Karen I. Goldberg, and D. Michael Heinekey: Pincer Complexes as Catalysts for Amine Borane Dehydrogenation.- Dmitri Gelman and Ronit Romm: PC(sp3)P Transition Metal Pincer Complexes: Properties and Catalytic Applications.- Jennifer Hawk and Steve Craig: Physical Applications of Pincer Complexes.