Groups V and VI

Thermochemistry of gaseous transition metal complexes of group V and VI ligands. P. M. Burken-shaw and C. T. Mortimer, Coord. Chem. Rev., 1983,48,101-155 (110). 

Reactions of organic compounds with higher fluorides of /- and d-elements of groups V and VI. V. T. Orekhov, Russ. Chem. Rev. (Engl. Transl.), 1977, 46,420-435 (169). 

A set of oxygen donor atoms, providing both a and tt donation to a metal center, is not appropriate to stabilize any low oxidation state of a metal.19 This is, however, a synthetic advantage since very reactive, unstable, low-valent metalla-calix[4]arenes can be generated in situ and intercepted by an appropriate substrate. In the absence of a suitable substrate, the reactive fragment, however, can collapse to form metal-metal bonded dimers. The formation of metal-metal bonds has been, however, so far observed in the case of Group V and VI metals only. The most complete sequence so far reported has been for tungsten, molybdenum, and niobium. 

Groups V and VI, is higher for the lower fluorides of the halogens or xenon a comparative study of Cornwell effects would be of interest here. 

FP methods inherently lead to a marked sinusoidal variation of /ffp h across the periodic table (Pettifor 1977) and for Group V and VI elements, electron energy calculations predict j/f e -c p h- of opposite sign to those obtained by TC methods. It is worth noting, however, that a sinusoidal variation is reproduced by one of the more recent TC estimates (Saunders et al. 1988) although displaced on the energy axis (Fig. 6.7). 

Among the actinide compounds the interest is concentrating on binary compounds of simple structure (e.g. 1 1 compounds with elements of the groups V and VI of the periodic table) for which the theoretical treatment is rather advanced, and on intermetal-lic (e.g. Laves-) phases. 

The only route to dibenzenetitanium so far described is the reaction of titanium atoms with benzene the reductive routes that give access to arene complexes of Group V and VI metals fail for titanium. Although yields of about 30% are reported for the preparation of dibenzene-, ditoluene-, and dimesitylenetitanium, the reactions are more sensitive than most to the effect of excess metal. Unless the ligand-to-titanium ratio is high and the rate of deposition of titanium vapor kept low, the products seem to be catalytically decomposed by finely divided Ti metal 4a, 7). 

Heteroaromatic Radicals, Part II Radicals with Group VI and Groups V and VI Ring Heteroatoms P. Hanson, Adv. Heterocycl. Chem., 1980, 27, 32-149. 

Furin GG, Bardin VV (1989) Higher Fluorides of Group V and VI Elements as Fluorinating Agents in Organic Synthesis. In ibid, p 117... 

Besides the above ligands containing elements of Groups V and VI, it is worth emphasizing the existence of compounds containing P,0-, P,S-, and P,Se-donor sets, from which metallochelates of type 534 were obtained [552],... 

Those donor atoms and/or groups are examined as donor centers in the problem of competitive coordination on which, due to the molecular structure of the ligand, the most favorable conditions are created for electrophilic attack by the metal, after taking into account the acceptor properties of the metal and the conditions of complex-formation reactions [19]. Such donor centers are mostly elements of a few main subgroups belonging to Groups V and VI of the Periodic Table, and also the unsaturated, aromatic, and heteroaromatic compounds which form the fundamentals of modern ligands (Chap. 2). 

While at Southampton, Campbell undertook a tremendous quantity of research, primarily on organometallic compounds of groups V and VI. A total of 19 publications resulted from her work at Southampton between 1945 and 1966 15 with her as... 

R. J. Mawby Substitution reactions of metal and organometal carbonyls with Group V and VI donor ligands, pp. 228-253 (165). 

Transition metal catalysts are useful for the polymerization of acetylenes. Ti catalysts are known to polymerize acetylene. Catalysts containing group V and VI transition metals (i.e., Nb, Ta, Mo, and W) polymerize substituted acetylenes (3, 4). The group V and VI transition metal catalysts can be classified into three groups (1) chlorides of Nb, Ta, Mo, and W (2) 1 1 mixtures of the metal chlorides with organometallic cocatalysts (e.g.. 

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