Spelling suggestions: "subject:"metallacycle"" "subject:"metallacycles""
1 |
Synthesis and reactions of ruthenafuransMorran, Paul David January 1996 (has links)
No description available.
|
2 |
Organometallic Manipulations of Fluoroolefins Mediated or Catalyzed by Low-Coordinate NickelSicard, Alexandre January 2016 (has links)
Fluoroolefins in general represent a valuable class of feedstock materials which have proven integral to a number of industries including (but not limited to) refrigeration, agrochemicals, pharmaceuticals, and propellants. As ligands for transition metals they are privileged in the relative inertness of the C–F bonds and their electrophilicity, which makes them ideal candidates for coordination chemistry with late, electron rich metals. The scope of this thesis encompasses work with TFE and VDF, two readily available fluoroolefins that are used most commonly in the polymer industry. Through the use of low-coordinate nickel systems, value-added derivatives of these two olefins have been prepared. With TFE, a T-shaped perfluoronickelacyclopentane was obtained upon coordination of the bulky SIPr ligand; this complex underwent hydrogenation to give 1H,4H-octafluorobutane at as low as 5 psi of hydrogen, in addition to giving rise to new ring-opened derivatives and a rare perfluorocyclobutyl complex. In the case of VDF, the regioselective hydrodefluorodimerization to a potentially valuable new refrigerant 2,4,4-trifluorobut-1-ene (HFO-1363pyf) catalyzed by nickel is reported, as well as a dimeric 2,4,4-trifluorobut-1-enylnickel derivative which is proposed in this text to originate from the β-fluoride elimination of an unprecedented 5-membered 2H,2H,4H,4H-tetrafluoronickelacycle.
|
3 |
Experimental and Theoretical Investigations of Anion-pi Interactions Metallacyclic Architectures of First-Row Transition Metals and N-Heteroaromatic LigandsGiles, Ian 2012 May 1900 (has links)
Research into anion-pi interactions has shifted from attempts to establish the legitimacy of the interaction to the incorporation of anion-pi interactions into supramolecular architectures. The research discussed in this dissertation explores the subtle effects of ligand, anion, and metal ion on supramolecular architectures of tetrazine-based ligands in the context of anion-pi interactions and their importance in the design and synthesis of supramolecular architectures.
Computational studies highlight the importance of the arene quadrupole moment, molecular polarizability, and substituent effects on the strength of anion-pi interactions. More importantly, however, this work establishes that there is a distinct directionality inherent to the anion-pi interaction between polyatomic anions and N-heterocycles, which can be used to direct ligands in supramolecular architectures as demonstrated through the work of the Dunbar group in recent years, particularly that of the square and pentagonal metallacycles.
The extension of metallacycles of bptz to CoII and FeII demonstrates the ability to tune the size of the metallacyclic cavity by simply changing the metal ion and results in the surprising encapsulation of two [SbF6]- anions in [Fe5(bptz)5(NCCH3)10][SbF6]10. 1H NMR spectroscopy and electrochemical studies reveal slight but significant differences characteristic of the square and pentagonal metallacycles and support the presence of anion-pi interactions in solution and highlight the importance of the encapsulated anion in the templation and stability of the metallacycles. A study of the interconversion between the square and pentagonal metallacycles via 1H NMR is presented for the first time.
Increasing the pi-acidity of the chelating ligand from bptz to bmtz results in the encapsulation of only one [SbF6]- anion in [Fe5(bmtz)5(NCCH3)10][SbF6]10, maximizing anion-pi interactions with the ligand despite the tighter fit. A significant hurdle in the incorporation of different anions into the metallacyclic structures was overcome with the development of a new synthetic protocol for [Fe(NCCH3)6]2+ salts of a wide range of anions from sodium salts and Fe4Cl8(THF)6. Also, the nuclearity of the less stable [Fe5(bptz)5(NCCH3)10][PF6]10 metallacycle was established via a combination of MS, electrochemistry and 1H NMR experiments through comparisons with known FeII metallacycle solution behavior.
|
4 |
Studies on a Series of Transition Metal Complexes Derived from Alkyne-containing Bisphosphine Ligands / アルキン含有ビスホスフィン配位子より得られる遷移金属錯体に関する研究Sasakura, Kohei 27 July 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22702号 / 工博第4749号 / 新制||工||1742(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 大江 浩一, 教授 近藤 輝幸, 教授 中尾 佳亮 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
|
5 |
Metal-chalcogen-nitrogen ring complexes and crystallographic studiesWaddell, Paul G. January 2010 (has links)
A series of Pt(S₂N₂)(P(OR)[subscript n]R′[subscript(3-n)])₂ complexes were prepared and analysed using ³¹P NMR and IR spectroscopy, elemental analysis and X-ray crystallography. Similarly, a series of Pt(SeSN₂)(P(OR)[subscript n]R′[subscript(3-n)])₂ complexes were also prepared and analysed. The ¹J[subscript(Pt-P)] coupling constants and Pt-P bond lengths for these complexes are influenced by the oxygen content of their phosphorus ligands. The ³¹P NMR spectra for a series of [Pt(S3N)(P(OR)[subscript n]R′[subscript(3-n)])₂][BF₄] complexes are also reported. Planar [S₂N₂H]⁻ complexes were prepared and the X-ray crystal structure of [Pd(S₂N₂H)(bipy)][Cl] is reported. The X-ray structures of MX₂(P(OR)[subscript n]R′[subscript(3-n)])₂ are reported and compared with the previously reported analogues. The magnitude of the ¹J[subscript(Pt-P)] varies linearly with the Pt-P bond length (l[subscript(Pt-P)] = 2.421 – J/24255) for the 12 platinum-containing complexes. This correlation is compared to that of a larger series of complexes. A series of M(ndsdsd₂ (ndsdsd = bis[(nitrilo(diphenyl)-λ⁶-sulfanyl)](diphenyl)-λ⁶-sulfanediimide (Ph₂S(=N-(Ph₂)S≡N)₂)) complexes were prepared and characterised using elemental analysis and multinuclear NMR and IR spectroscopy where appropriate. The X-ray crystal structures of five examples are reported.
|
Page generated in 0.0261 seconds