239809-54-2Relevant academic research and scientific papers
Titanium σ-acetylides as building blocks for heterobimetallic transition metal complexes: Synthesis and redox behaviour of π-conjugated organometallic systems
Back, Stephan,Gossage, Robert A.,Rheinwald, Gerd,Del Rio, Ignacio,Lang, Heinrich,Van Koten, Gerard
, p. 126 - 138 (1999)
A series of related Ti σ-acetylides of the type {Ti}C≡CR ({Ti} = (η5-C5H5)2 Ti(CH2SiMe3); 2: R = SiMe3; 3: R = C6H3(CH2NMe2)2-3,5; 4: R = C6H2I-4-(CH2NMe2)2-3,5; 5: R = C6H4CN-4; 6: R = C5H4N-4; 7: R = Fc, Fc = (η5-C5H4)Fe(η5-C 5H5); 8: R = C6H4(C≡C{Ti})-4) have been prepared by reacting the corresponding lithium acetylides with {Ti}Cl (1). The X-ray crystal structure determination of (Ti)C≡CSiMe3 (2) is reported. This compound exhibits a one-dimensional (1D) arrangement with respect to the Ti-C≡C unit. The reaction of 2 with [CuCl]n afforded 1 and [CuC≡CSiMe3]n (10) and is proposed to occur via prior formation of the dimeric intermediate [(η2-{Ti}C≡CSiMe3)2Cu 2Cl2]. The chemical oxidation of {Ti}C≡CFc, 7, with Ag[BF4] yielded HC≡CFc and an undefined Ti species. Treatment of 5 or 6 with {Ru}N≡N{Ru} ({Ru} = mer,trans-[RuCl2(NN′N)]; NN′N = η3-C5H3N(CH2NMe 2)2-2,6) produced intensively coloured heterodinuclear compounds, such as [{Ti}C≡CC5H4N-4]{Ru} (16). In contrast, 5 and 6 react with cationic Pt compounds of the type [{Pt}·L][X] ({Pt} = [Pt(C6H3{CH2NMe2} 2-2,6]+ ; L = H2O, MeCN; X = BF4, OTf) to give product mixtures rather than defined compounds. Electrochemical studies on some of the bimetallic compounds show that the Ti(III)/Ti(IV) redox potential appears to be reversible and is shifted to a more negative value upon substitution of the Cl ligand in 1 by C≡CR (compounds 2-8). Whereas the nature of R in {Ti}C≡CR has an influence on the Ti(III)/Ti(IV) redox potential, the attachment of a second metal onto the π-conjugated system has only negligible effect on the electrochemical properties of the Ti centre.
