Polarised alkynyl ruthenium complexes.
Date
2010
Authors
Parker, Christian Richard
Editors
Advisors
Bruce, Michael Ian
Cole, Marcus
Sumby, Christopher James
Cole, Marcus
Sumby, Christopher James
Journal Title
Journal ISSN
Volume Title
Type:
Thesis
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Abstract
Chapter 1 outlines the potential application of metal alkynyl complexes and then describes the different methods in the literature for the synthesis of alkynyl, poly-ynyl and homo- and hetero-metal complexes. Their chemistry will then be discussed. This Chapter concludes with an outline of the work to be described in the remainder of the thesis. Chapter 2 describes a series of complexes containing a new tricyanovinylethynyl (3,4,4-tricyanobut-3-en-1-ynyl) ligand obtained by direct substitution of a CN group in tetracyanoethene by ethynyl complexes M(C=CH)(PP)Cp' [M = Ru, Os, (PP)Cp' = (PPh₃)₂Cp; M = Ru, PP = dppe, Cp' = Cp, Cp*]. The reactions proceed in higher yield as the metal environment becomes sterically larger and more donating; the normal [2 + 2]-cycloaddition / ring-opened product M{C[=C(CN)₂]CH=C(CN)₂}(PP)Cp' is also formed in some cases. The diynyl Ru(C=CC=CH)(dppe)Cp* reacts with tcne to give only the ring-opened adduct Ru{C=CC[=C(CN)₂]CH=C(CN)₂}(dppe)Cp*. Protonation of Ru{C=CC(CN)=C(CN)₂}(dppe)Cp* (10) afforded the vinylidene. A second transition metal fragment {MLn} [{MLn} = Ru(PPh₃)₂Cp, M'(dppe)Cp* (M' = Ru, Os), RuCl(dppe)₂] can be added to the CN group trans to the first. Compound 10 ready undergoes substitution of the 3-cyano group by nucleophiles. Some unexpected rearrangements and formation of O- and N-heterocyclic compounds were also found. Chapter 3 describes reactions between 1,2 dichlorohexafluorocyclopentene and Ru(C=CH)(dppe)Cp* (1) or Ru(C=CC=CLi)(dppe)Cp* which give Ru(C=C-c-C₅F₆Cl-2)(dppe)Cp* (36) and Ru(C=CC=C-c-C₅F₆Cl-2)(dppe)Cp*, respectively. Ready
hydrolysis of 36 to Ru{C=C[c-C₅F₄Cl(O)]}(dppe)Cp* occurs, which can be converted to Ru{C=C(c-C₅F₄Cl[=C(CN)₂])}(dppe)Cp* by treatment with CH₂(CN)₂ / basic alumina. The cyano-fluorocarbon ligand in the latter is one of the most powerfully electron-withdrawing groups known. Chapter 4 describes the three methods of synthesising heterometallic carbon-chain complex {Cp*(dppe)Ru}C=CC=CC=CC{Co₃(μ-dppm)(CO)₇} (40), in two examples showing the first examples of Ru{(C=C)xI}(dppe)Cp* (x = 1, 2) being used in a cross coupling reaction with Ph₃ PAu(C=C)(₃-x)C{Co₃(μ-dppm)(CO)₇}. The reactivity of 40 with PPh₃, MeOTf, tcne, tcnq, Fe₂(CO)₉, NiCp₂ and Co₂(CO)₈ took place on either the C₈ bridge or on either metal centre. Chapter 5 discusses the reaction of 1 with oxalyl chloride which gave {Cp*(dppe)RuC=C}₂CO (52). This complex can be methylated to give [{Cp*(dppe)RuC=C}₂C(OMe)]OTf, which in turn can be protonated to the dication. Knövenagel condensation of 52 with CH₂(CN)₂ gave {Cp*(dppe)RuC=C}₂C{=C(CN)₂}. The reaction of 1 and bis(2,4-dinitrophenyl) oxalate afforded {Cp*(dppe)Ru}{c- C=C[C₆H₃(NO₂)₂]C(O)C(O)O}. The transmetallation reaction of {(Ph₃P)AuC=C}₂CO and RuCl(dppe)Cp unexpectedly gave the cyclic complex [1,4-{Cp(dppe)Ru}₂{c- COC(OMe)=CHCCH}]PF₆. Chapter 6 gives an account of the electrochemistry of many of these redox-active compounds and examines the UV-Vis absorption of the more polarised compounds.
Some discussion of the various observed trends is presented. There is also a future direction of this chemistry given at the end of this work.
School/Discipline
School of Chemistry and Physics
Dissertation Note
Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2010
Provenance
Copyright material removed from digital thesis. See print copy in University of Adelaide Library for full text.