Chemistry of zerovalent tungsten alkoxides. Synthesis, x-ray structure and reactivity toward carbon dioxide

The first organometallic carbonyl tungsten complex of antibacterial drug norfloxacin

“…Moreover, the uncoordinated H-Norf is parallel to the coordinated H-Norf. The average W-C distance is 1.921 Å , which is comparable to that found in bis(bis(triphenylphosphine)iminiumbis(2,2,2-trifluoroethaxo)-tetracarbonyltungste) (W-C 1.926 Å ) [9], but significantly shorter than that found in (l 2 -dimethylamido) tricarbonyldimethylaminotetrakis(l 2 -2,2,2,3,3,3-hexafluoro-t-butyloxy)-ditungsten] (2.020 Å ) [10] and [bis(tetraethylammanium)(3,5-di-t-butylcatecholato)-tetracarbonyltungsten (W-C 1.982 Å ) [11]. However, the difference of W-C (1.902-1.933 Å ) is slightly less than those found in nonacarbonylbis(l 3 -ethoxo)-(l 2 -ethoxo)-tris(triphenylphosphine)trigold-tri-tungsten (1.737-1.923 Å ) [12], bis(tetraethylammonium)-bis(l 2 -methoxo)tetracarbonyltungsten] (1.959-2.025 Å ) [13], and bis(triphenylphosphine)iminium (l 2 -oxalato) bis-(tetracarbonyl-tungsten)-diethylether solvate [1.934-2.027] [14].…”

Insertion of Unsaturated Organic Electrophiles into MolybdenumAlkoxide and RheniumAlkoxide Bonds of Neutral, Stable Carbonyl Complexes

“…This is an important difference with regard to the zero-valent group 6 anionic alkoxo carbonyl complexes studied by Darensbourg: In this case the p-donor alkoxo ligand causes a strong CO-labilization, [11] that may result in the formation of bimetallic or cluster compounds in which the alkoxo groups act as bridging ligands. Another feature of those zero-valent complexes, not shared by the alkoxo derivatives reported here, is their tendency to undergo b-elimination reactions unless electron-withdrawing substituents are present at the alkoxo group.…”

Reversible Insertion of Methyl Isothiocyanate into Copper(I) Aryloxides

“…So, the validity of extending the reactions of these heterocumulenes to the reactions of CO 2 has been challenged − One can then ask, would it be possible to make heterocumulene reactions reversible by electronic perturbations? …”