Butadiynyl complex

The first isolable, albeit binuclear, butatrienylidene complexes, the cationic diiron complexes 8, were likewise prepared by addition of an electrophile E+ to neutral butadiynyl complexes. Instead of mononuclear butadiynyl complexes, binuclear C4-bridged butadiyndiyl complexes 7 were used as the starting complexes by Lapinte et al. (Scheme 3.4) [18]. Complexes 8 were characterized by multinuclear NMR, IR, UV-vis, and Mossbauer spectroscopies, mass spectrometry and cyclic voltammetry. 

Scheme 3.2 Generation of [Cp(PPh3)2Ru=(C)4H2] by protonation of a butadiynyl complex with trifluoroboric acid and subsequent reaction with water.

Pentacarbonyl(dimethylvinylidene) chromium, generated in situ, also reacts with the butadiynyl complexes 34 at —60 °C by regiospecific cycloaddition of the bond of the... 

Extension of this work to the triynyl system was accomphshed by reacting the butadiynyl complexes with an acetylenic proton, [Re(CO)3(N N)(C=C-C=CH)], with an excess of bromo- or iodoalkynes in the presence of a catalytic amount of... 

Iron and cobalt with additional C4H and C4 ligands begin this section. The carbon-containing ligands are left over from butadiynyl complexes. 

Hexaynes (C6H3) (C=C—C=C -)3 Tris(butadiynyl)benzenes such as 1,3,5-(RC=C C=C)j-C6H3 give the complexes 118 when six equivalents of titanocene are used. Treatment with three equivalents of zirconocene gives the tris(cyclocumulene) 119, and treatment of the latter with three additional equivalents yields the threefold C—C cleaved product 120 [59]. 

The use of ethynyl- or butadiynyl-substituted 7r-complexes as intermediates for the synthesis of compounds which are typically larger than conventional organic... 

The synthesis introduced by Bruce et al. starts from butadiynyl lithium [14]. The addition of HBF4 to solutions of buta-l,3-diynyl ruthenium complex 3 was proposed to afford the butatrienylidene cation 4 by protonation of the terminal carbon atom of the butadiynyl ligand. Complex 4 could neither be isolated nor spectroscopically detected. It readily decomposed by reaction with even traces of water in the air by nucleophilic attack of H2O on the cationic center (Scheme 3.2). 

The first neutral pentatetraenylidene complex was obtained by Werner et al. Treatment of a solution of the butadiynyl(hydrido) complex 21 at —78°C with an equimolar amount of (Cp3S02)20 followed by addition of two equivalents of NEt3 at... 

The polymer whose backbone is composed of platinum and alternately arranged butadiynyl and phenylenediethynylene groups, Pt-D1-Pt-D2 has been prepared by condensation of binuclear complex (38 a) with p-diethynylbenzene according to Eq. 22. Similarly, polymers, Pt-D -Pt-D1-Pt-D2 and Pt-D -Pt-D3, have been synthesized as described in Eqs. 23 and 2442). 

Scheme 6.11 Oxidation induced coupling of a butadiynyl ruthenium complex.

An interesting class of cationic polyyne polymers (5.24) was prepared by reaction of the bimetallic complex /i-butadiynyl-bis[transmain chain (Eq. 5.13). Other analogous polyelectrolytes have been obtained similarly by the use of the appropriate dihalide complex and bipyridyl derivatives [37]. 

A Pt2Ag4 complex having bridging butadiynyl ligands 718 shows intense luminescence due to MLCT transitions. Reaction of Cd(C104)2 with [Pt(C=CPh)4] produces the heterobimetallic compound, Pt4Cd6(C=CPh)4(/.4-G=CPh)i2(M-OH)4 719, which contains [Gd8(//-OH)4] + as the core of the cluster. ... 

A new series of ferrocenyl end-capped bis(butadiynyl) fluorene complexes [(t -C5H5)Fe(p"-C5H4)C=CC=CRC=CC C(p"-C5H4)Fe(ii -C5H5)] (R = fluoren-9-one-2,7-diyl 30, 9,9-dihexylfluorene-2,7-diyl 31, 9-ferrocenylmethylenefluorene-2,7-diyl 32, 9-... 

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