Comparative reactivity study of cyclopentadienyl and fulvalene molybdenum complexes

Syntheses and Structures of Buta-1,3-Diynyl Complexes from “on Complex” Cross-Coupling Reactions

“…The compound 4a was also studied to aid the assignment of 13 C NMR spectra in the series 4a -e. Each system was fully optimized without symmetry constraints, with frequency calculations indicating each structure to be a true minimum. The resulting computational systems are denoted 4a´, 5´ and 6´ to distinguish them from the physical complexes.…”

“…Metal oligo/polyynyl M{(C≡C) n H}L x species have attracted significant interest over several decades, serving as scaffolds for the assembly of bi- [1][2][3][4][5][6][7][8][9][10][11][12][13] and poly-metallic [14][15][16][17][18][19][20][21][22][23][24][25][26] complexes, and as models and building blocks for metallomacrocycles, 15,[27][28][29] and metallo-polymers. [30][31][32][33][34][35] Detailed studies of the underlying electronic structure of this family of complexes have been undertaken, using a variety of computational and spectroscopic methods, often with a view to modelling the behavior of these prototypical molecular wires.…”

“…Identification of the products was readily achieved through a combination of IR, 1 H, 13 C and 31 P NMR spectroscopies, MALDI-TOF and high-resolution ES mass spectrometry. The phosphine ligands were detected in the 31 that can be approximated as the local oscillations of the C≡CAr and Ru-C≡C fragments, respectively.…”

12 Chromium, molybdenum and tungsten

“…Several new species are reported. 27 Reactions of halogenofluorocarbons with [Cp 2 M(L)] (M = Mo, W; L = C 2 H 4 , CO) have been studied. Mechanistic aspects are discussed, including those for fluoroalkylation at the metal centres, the cyclopentadienyl rings and the ethylene ligands.…”

Synthesis and structure of the diynyl complexes [Mo(CCCCR)L2(η-C7H7)], L2=chelate N- or P-donor ligand, R=SiMe3 or H: X-ray crystal structures of [Mo(CCCCSiMe3)(2,2′-bipyridine)(η-C7H7)] and [Mo(CCCCH)(Ph2PCH2CH2PPh2)(η-C7H7)]

“…Investigations into metal-diynyl and all-carbon-bridged diyndiyl complexes of the group VI metals are well developed for d 4 systems based upon Mo(CO)(dppe)Cp [16,17] and W(CO) 3 (g-C 5 R 5 ) (R = H, Me) [18,19] as supporting fragments whilst we have previously reported the syntheses of butadiynyl derivatives of dicarbonyl cycloheptatrienyl molybdenum complexes [Mo(C"CC"CR)(CO) 2 (g-C 7 H 7 )] (R = SiMe 3 or H) [20]. However, where the redox chemistry of these examples has been investigated [19] it is clear that the presence of carbonyl acceptor groups results in poor accessibility of higher oxidation states and therefore limited application as end-caps in all-carbon bridged organometallics.…”