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Controlled synthetic approach to di- and trinuclear ruthenium acetylide complexes

This thesis describes the synthesis and characterisation of a variety of acetylide-bridged di- and trinuclear ruthenium acetylide complexes that were prepared in a controlled fashion, and the preparation and characterisation of the ruthenium(II) complexes required for these stepwise reactions. These precursor complexes, or building blocks, include dimethyl-, acetylidomethyl-, and bis(acetylido)ruthenium(II) complexes. An introduction to metal acetylide chemistry is presented in Chapter 1. The previous research in this area is briefly reviewed, and the potential applications of these complexes are highlighted. The primary aims of this course of work are outlined, namely, to develop a controlled synthetic approach to the synthesis of oligonuclear ruthenium acetylide complexes. The synthetic strategies for this aim are introduced in Chapter 2, and the synthetic routes to cis and trans-Ru(CH3)2(dmpe)2 (25/23) and cis and trans-Ru(CH3)2(depe)2 (26/24) are described. Characterisation of the novel, synthetically important trans-Ru(CH3)2(dmpe)2 (23) is completed by an examination of its X-Ray crystallographic structure. Chapter 3 describes the thermal and photochemical metathesis reactions of trans-Ru(CH3)2(dmpe)2 (23) with terminal acetylenes, and the preparation of a variety of acetylidomethylruthenium(II) complexes, trans-Ru(CH3)(C≡CR)(dmpe)2 (R = Ph (30), tBu (31), SiMe3 (32), C6H4-4-tBu (33), C6H3-3,5-tBu2 (34), C6H4-4-C≡CH (35), C6H4-4-OCH3 (36), C6H4-4-CH3 (37), C6H3-3,5-(CF3)2 (38)). The characterisation of these complexes by NMR spectroscopy, IR spectroscopy and X-Ray crystallography is presented. A clean and high yielding synthesis of the synthetically significant unsymmetrical bis(acetylido)ruthenium(II) complexes was developed via the reaction of an acetylidomethylruthenium(II) complex with an excess of a second terminal alkyne in a mixture of methanol and benzene. The characterisation of the novel complexes trans-Ru(C≡CR)(C≡CR′)(dmpe)2 (R = Ph, R′ = tBu (40), SiMe3 (41), C6H4-4-C≡CH (44); R = tBu, R′ = SiMe3 (42), C6H4-4-C≡CH (43), C6H4-4-tBu (45), C6H3-3,5-tBu2 (46)) by NMR and IR spectroscopy, mass spectrometry and X-Ray crystallography is described in Chapter 4. Additionally, Chapter 4 describes the synthesis and characterisation of symmetrical bis(acetylido)ruthenium(II) complexes, and a number of organic butenyne compounds, which were observed as by-products from the attempted synthesis of several of the bis(acetylido)ruthenium(II) complexes. Dinuclear ruthenium(II) complexes were prepared by the reaction of trans-Ru(C≡CR)(C≡CC6H4-4-C≡CH)(dmpe)2 (R = tBu (43) or Ph (44)) with an acetylidomethylruthenium(II) complex in toluene and methanol. Both symmetrical and unsymmetical dinuclear complexes could be prepared in this way, and were characterised by a range of techniques including NMR spectroscopy, IR spectroscopy, mass spectrometry and X-Ray crystallography, and are described in Chapter 5. In addition, an electrochemical study of one of the dinuclear complexes was undertaken using cyclic voltammetry. The symmetrical trinuclear ruthenium(II) complexes, trans,trans,trans- (RC≡C)Ru(dmpe)2(μ-C≡CC6H4C≡C)Ru(depe)2(μ-C≡CC6H4C≡C)Ru(dmpe)2(C≡CR) (R = Ph (80), tBu (81), SiMe3 (82)) was prepared by the reaction of two equivalents of an acetylidomethylruthenium(II) complex with the symmetrical bis(acetylido)ruthenium(II) complex, trans-Ru(C≡CC6H4-4-C≡CH)2(depe)2 (54), in toluene and methanol. These syntheses, and the subsequent characterisation of the products are also reported in Chapter 5. The primary aim of this thesis, viz. the synthesis and characterisation of acetylide bridged di- and trinuclear ruthenium acetylide complexes in a controlled fashion, was successfully achieved. Suggestions for future work are described in Chapter 6.

Identiferoai:union.ndltd.org:ADTP/272545
Date January 2009
CreatorsShearer, Timothy Kenneth, Chemistry, Faculty of Science, UNSW
PublisherAwarded By:University of New South Wales. Chemistry
Source SetsAustraliasian Digital Theses Program
LanguageEnglish
Detected LanguageEnglish
Rightshttp://unsworks.unsw.edu.au/copyright, http://unsworks.unsw.edu.au/copyright

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