Metal coordination to a dimetallaoctatetrayne

Abstract

The ditungstaoctatetrayne [(Tp*)(CO)2WCCCCCCW(CO)2(Tp*)] (Tp* = hydrotris(dimethylpyrazolyl)borate) regioselectively adds extraneous metal–ligand fragments to the internal CC or terminal WC triple bonds leading to new tri-, tetra- or hexametallic assemblies.

Iron Versus Ruthenium: Evidence for the Distinct Differences in the Electronic Structures of Hexa-1,3,5-triyn-1,6-diyl-bridged Complexes [Cp*(dppe)M}{μ-(C≡C)3}{M(dppe)Cp*}]+ (M = Fe, Ru)

“…Homo- and hetero-bimetallic polyyndiyl complexes of the general form [{L n M}­{μ-(CC) m }­{ML n }] n + have proved to be objects of sustained interest over the past decades. , The metal end-capping groups have allowed for stabilization of carbon chains of various lengths and formal valence structures, the longest members of the series serving as models for the putative linear carbon allotrope carbyne. − Polyyndiyl complexes have allowed the reactivity profile of the stabilized carbon fragments to be explored and, in addition to serving as “carbon in a bottle” reagents, − the combination of redox-active metal fragments {ML n } with the extended π-conjugated electronic structure of the bridging polyyndiyl chain has made these all-carbon bridged bimetallic complexes popular systems through which to study intramolecular electron-transfer phenomena in mixed-valence derivatives. ,− …”

Synthesis and reactivity of 9,10-bis(4-trimethylsilylethynylbuta-1,3-diynyl)anthracene derived chromophores

“…In contrast to compounds 1 , 5 , 6 and 8–10 , appending metals to the diynyl units, either peripherally (dicobaltatetrahedrane 7 formation) or as a terminus in the bis(carbyne) 11 , unsurprisingly results in complete quenching of fluorescence, as has been noted in other instances where carbyne units have been appended to extended aromatic cores. 18 Thus while heavy atom inclusion of bromine in 6 or gold in 8 and 9 might be expected to result in quenching, these are remote from the foci of the electronic transitions and in the case of Au( i ), the metal is closed shell d 10 with little expectation of significant electronic communication. For the bis(carbyne) 11 , however, the MoC linkage is itself a chromophore (d xy → π MoC and π MoC → π* MoC ) and the metal orbitals are expected to be strongly conjugated to the extended π-system.…”

Heterobimetallic μ2-halocarbyne complexes

“…This pair of carbyne complexes joins a small number of octahedral Tp or Tp* carbyne complexes for which data are available for both the low-valent dicarbonyl and high-valent dihalo examples. 67–70 Carbon-13 NMR spectroscopic and crystallographic data of interest for these complexes are collected in Table 6 whilst computationally-derived data for the model complexes [W(CCl)(CO) 2 (Tp)] ( 1b′ ) and [W(CCl)Cl 2 (Tp)] ( 9′ ) are included in Table 2.…”

“…24 Furthermore, we have extended this to carbon wire C 2 and C 6 ditungsten systems. 25 In terms of heteroatom -functionalised carbynes, the approach is so far limited to Hughes’ examples noted above, a boryloxy example [WPt{μ 2 -COB(NMe 2 )B(NMe 2 )C 5 H 4 }(CO) 2 (PPh 3 ) 2 ] 26 and phosphonio-, phosphino-, arsino and arsoniocarbynes. 27…”