Early Transition Metal Complexes Stabilized by Bulky Aminopyridinato Ligands
Author : Awal Noor
Publisher :
Page : 126 pages
File Size : 47,72 MB
Release : 2008
Category :
ISBN :
Author : Awal Noor
Publisher :
Page : 126 pages
File Size : 47,72 MB
Release : 2008
Category :
ISBN :
Author : Jamie Hicks
Publisher : Springer
Page : 196 pages
File Size : 37,48 MB
Release : 2018-06-29
Category : Science
ISBN : 9789811097362
This thesis describes the synthesis and characterization of numerous metal-metal bonded complexes that are stabilized by extremely bulky amide ligands. It provides a comprehensive overview of the field, including discussions on groundbreaking complexes and reactions, before presenting in detail, exciting new findings from the PhD studies. The thesis appeals to researchers, professors and chemistry undergraduates with an interest in inorganic and/or organometallic chemistry.
Author : Jessica Nicole Boynton
Publisher :
Page : pages
File Size : 14,88 MB
Release : 2014
Category :
ISBN : 9781321210804
The research in this dissertation is focused on the synthesis, structural, and magnetic characterization of two-coordinate open shell (d1-d4) transition metal complexes. Background information on this field of endeavor is provided in Chapter 1. In Chapter 2 I describe the synthesis and characterization of the mononuclear chromium (II) terphenyl substituted primary amido complexes and a Lewis base adduct. These studies suggest that the two-coordinate chromium complexes have significant spin-orbit coupling effects which lead to moments lower than the spin only value of 4.90 [mu]B owing to the fact that [lambda] (the spin orbit coupling parameter) is positive. The three-coordinated complex 2.3 had a magnetic moment of 3.77 [mu]B. The synthesis and characterization of the first stable two-coordinate vanadium complexes are described in Chapter 3. The values suggest a significant spin orbital angular momentum contribution that leads to a magnetic moment that is lower than their spin only value of 3.87 [mu]B. DFT calculations showed that the major absorptions in their UV-Vis spectra were due to ligand to metal charge transfer transitions. The titanium synthesis and characterization of the bisamido complex along with its three-coordinate titanium(III) precursor are described in Chapter 4. Compound 4.1 was obtained via the stoichiometric reaction of LiN(H)AriPr 6 with the Ti(III) complex TiCl3 *2NMe3 in trimethylamine. The precursor 4.1 has trigonal pyramidal coordination at the titanium atom, with bonding to two amido nitrogens and a chlorine as well as a secondary interaction to a flanking aryl ring of a terphenyl substituent. Compound 4.2 displays a very distorted four-coordinate metal environment in which the titanium atom is bound to two amido nitrogens and to two carbons from a terphenyl aryl ring. This structure is in sharp contrast to the two-coordinate linear structure that was observed in its first row metal (V-Ni) analogs. The synthesis and characterization of mononuclear chromium(II) terphenyl primary substituted thiolate complexes are described in Chapter 5. Reaction of the terphenyl primary thiolate lithium derivatives LiSAriPr4 and LiSArMe6 with CrCl2THF2 in a 2:1 ratio afforded complexes 5.1 and 5.2, which are the very rare examples of chromium(II) thiolates with quasi-two-coordination at the metal center. Both deviate from linearity and have S-Cr-S angles of 111.02(3)° and 107.86(3)° with secondary Cr-C(aryl ring) interactions of ca. 2.115 Å and 1.971 Å respectively. The initial work on titanium and vanadium terphenyl thiolates is described in Appendix I and II. In Chapter 6 I show that the reaction of K2COT (COT= 1,3,5,7-cyclooctatetraene, C8H8) with an aryl chromium(II) halide gave (CrAriPr4)2([mu]2-n3:n4-COT) (6.1) in which a non-planar COT ring is complexed between two CrAriPr4 moieties -- a configuration previously unknown for chromium complexes of COT. OneCr2+ ion is bonded primarily to three COT carbons (Cr--C= 2.22-2.30 Å ) as well as an ipso carbon (Cr-C= ca. 2.47 Å) from a flanking aryl ring of its terphenyl substituent. The other Cr2+ ion bonds to an ipso carbon (Cr-C= ca. 2.53 Å) from its terphenyl substituent as well as four COT carbons (Cr--C= 2.24-2.32 Å). The COT carbon-carbon distances display an alternating pattern, consistent with the non-planarity and non-aromatic character of the ring. The magnetic properties of 6.1 indicate that the Cr2+ ions have a high-spin d4 configuration with S = 2. The temperature dependence of the magnetism indicates that their behavior is due to zero-field splitting of the S = 2 state. Attempts to prepare 6.1 by the direct reaction of quintuple-bonded (CrAriPr4)2 with COT were unsuccessful. (Abstract shortened by UMI.) --Proquest.
Author : Veeranna Yempally
Publisher :
Page : pages
File Size : 38,8 MB
Release : 2012
Category :
ISBN :
The role of bulky tin ligands in the stabilization of transition metal complexes with electronic unsaturation has been studied to understand the mode of binding of small molecules at an unsaturated metal center. We were able to isolate electronically unsaturated Pt-Sn bimetallic complexes effective in the reversible activation of small molecules including CO, H2, C2H4, and NH3 at room temperature. We have examined the effect of the modification of ligands in Pt-Sn bimetallic complexes for the activation of small molecules and have observed that the Pt(SnBut3)2(CNBut)2 bimetallic complex reversibly activates hydrogen at room temperature both in the solid state and in solution. Similarly, we have also prepared bimetallic Pt-Sn complexes with an NHC carbine ligand which were also shown to activate hydrogen and alkenes reversibly. A bimetallic Fe-Sn cluster complex, Fe2 ([mu]-SnBut2)2(CO)8, was synthesized from the reaction of But3SnH with the Fe2(CO)9 and shown to be selective at activating the benzylic C-H bond of alkylaromatic solvent molecules. The new complexes containing tin have been characterized spectroscopically to gain an insight into the reaction mechanism involved in small molecule activation.
Author : Remi Chauvin
Publisher : Springer
Page : 260 pages
File Size : 45,15 MB
Release : 2009-12-18
Category : Science
ISBN : 364204722X
Contents: Yves Canac and Remi Chauvin: Neutral eta1-carbon ligands: beyond carbon monoxide; Esteban P. Urriolabeitia: Ylide Ligands; Wolfgang Petz and Gernot Frenking: Carbodiphosphoranes and related ligands; Mareike C. Jahnke and F. Ekkehardt Hahn: Chemistry of N-Heterocyclic Carbene Ligands; Tsuyoshi Kato, Eddy Maerten, Antoine Baceiredo: Non-NHCs stable singlet carbene ligands; Victorio Cadierno, Sergio E. García-Garrido: All-Carbon-Substituted Allenylidene and Related Cumulenylidene Ligands; Victorio Cadierno, Sergio E. García-Garrido: Heteroatom-Conjugated Allenylidene and Related Cumulenylidene Ligands.
Author : David L. Kepert
Publisher :
Page : 520 pages
File Size : 13,69 MB
Release : 1972
Category : Science
ISBN :
Author : Christopher R. Yeisley
Publisher :
Page : 68 pages
File Size : 24,42 MB
Release : 2013
Category : Catalysts
ISBN :
Author : Christopher Peter Gerlach
Publisher :
Page : 430 pages
File Size : 47,77 MB
Release : 1997
Category :
ISBN :
Author : Anthony F. Hill
Publisher : Academic Press
Page : 484 pages
File Size : 41,13 MB
Release : 2013-09-11
Category : Science
ISBN : 0124078419
Almost all branches of chemistry and material science now interface with organometallic chemistry--the study of compounds containing carbon-metal bonds. This widely acclaimed serial contains authoritative reviews that address all aspects of organometallic chemistry, a field that has expanded enormously since the publication of Volume 1 in 1964. Informs and updates on all the latest developments in the field Contributions from leading authorities and industry experts
Author : Charles Andrew McAuliffe
Publisher :
Page : 0 pages
File Size : 23,31 MB
Release : 1973
Category : Antimony compounds
ISBN : 9781349815609