Substituted cyclopentadienyl(dithiolene)tungsten(IV) products from alkyne addition to tungsten(II) dithiocarbamate reagents

Abstract

1923all other four-coordinate intermediate-spin (S = 1) Fe(I1) porphyrins studied to date.4J6*20 The spin delocalization mechanism for S = 1 Fe(I1) porphyrins has been shown to be P -Fe ?r charge transfer.16v21*22 It has been argued16 that contact contributions to the isotropic shifts of the phenyl protons of Fe(TPP) are very small, so that these isotropic shifts are dominated by dipolar contribution^^^*^^ w m d i p = (-1/3~)[x,, -1/z(xXx + X,)I ((3 cos2 e -

Facets of early transition metal–sulfur chemistry: Metal–sulfur ligand redox, induced internal electron transfer, and the reactions of metal–sulfur complexes with alkynes

“…A very unusual example is the reaction of the g 2 -alkyne complex, W(g 2 -PhCCH) 2 (S 2 CNMe 2 ) 2 , with excess PhCCH to give (84), containing amidocyclopentadienyl and dithiolene ligands formed by the combination of parts from a single dithiocarbamate ligand with three equivalents of alkyne [146]. Dithiocarbamate salts also react with hexafluorobut-2-yne complexes, CpMCl {g 2 -C 2 (CF 3 ) 2 } (M = Mo, W), to form (85) and (86), the former being converted to the latter upon photolysis [147].…”

Synthesis and reactivity of oxygen ligated molybdenum(II) carbonyl complexes

“…These sulfur based ligands have been used to model the active sites of some Mo/W containing enzymes, such as acetylene hydratase [5,13], but they are not without their drawbacks. The sulfur atoms are prone to redox chemistry and C-S bond cleavage reactions, which limit the utility of the compounds [14][15][16][17][18][19][20][21][22]. Moving to an oxygen based chelate will eliminate these undesirable side reactions and stabilize the metal with stronger field oxygen donor atoms.…”

Functionalized Ferrocenes from [3+2] Cycloadditions in Bridging Vinylalkylidene Diiron Complexes

“…Alternative synthetic methods remain largely unexplored despite the fact that a number of metal-mediated [3+2] cycloadditions are well known which should, in theory, provide more direct routes to the formation of substituted cyclopentadienyl ligands. Few examples are reported in which [3+2] or [1+2+2] cycloadditions of coordinated ligands result in the direct assembling of cyclopentadienyls bearing substituents and functional groups. Even less investigated is the possibility that functionalized cyclopentadienyl complexes might be directly generated by assembling of bridging organic frames (C 2 or C 3 ligands), taking advantage of the activation effects due to multisite coordination…”