Group VB elements

Reaction of an alkyl (usually trimethyl) of Group-IIIb element (Al, Ga, In) with a hydride of a Group-Vb element (P, As, Sb) at 600-800°C and 1 atm. [4i][42] p. doping obtained from addition of diethyl zinc or bis(cyclopentadienyl) magnesium. 

The CVD of the III-V compounds is usually obtained by reacting an alkyl of a Group-IIIb element with a hydride of a Group-Vb element. These reactions have largely replaced the co-reduction of the halides, The general reaction is as follows ... 

Arsenic and antimony are Group VB elements and both occur in soils predominantly in - -3 and - -5 oxidation states and they have similar redox and sorption behaviour. The oxidized forms are rather insoluble in soils and the reduced forms much more soluble. 

Compared to vanadium, the higher oxidation states are much more frequently and the lower ones much less frequently encountered in niobium and tantalum. Niobium and tantalum are also much more prone to extended metal-metal bonding in their lower oxidation states V6-based clusters, for example, remain undiscovered. Little resemblance is found to the group VB elements phosphorus and arsenic. 

Carbollyl complexes of group VB elements have been mainly investigated by Todd s group (121). The heterogeneous reaction of the CHB10H30 anion... 

With the exception of nitrogen, all of the Group Vb elements are expected to form pentacoordinate compounds in their 5+ oxidation state, and this is, indeed, the case with some of the halides, alkoxides, etc. It was not until the pioneering work of Georg Wittig and his collaborators, however, that the first examples of pentaorganyls of these borderline elements between metals and metalloids were reported (95-99, 102, 104). In this early investigation, a complete set of the pentaphenyls could be obtained and characterized (95-99, 102), but apart from the pentamethyl-antimony case, all attempts for the preparation of pentaalkyl derivatives failed (104). 

In this article the author has been using the traditional ylide-ylene nomenclature as well as the modern phosphorane-arsorane-stiborane formalism. No attempt has been made to discriminate between one or the other of these modalities because it is felt that both offer a sufficiently clear description of at least those species that are derived from the main Group Vb elements. (Fortunately no Nli,s or BiR5 had to be given names.). However, when this procedure was followed with the vanadium, niobium, and tantalum compounds, an interesting problem arose because the authors... 

Two rare examples of unsubstituted Group VB elements bonded to transition metals are Co2(CO)6P2 and Co3(CO)9PS, which are produced from NaCo(CO)4 and PX3 and SPX3, respectively.35... 

Reactions of the Group Vb elements with the halogens are relatively straightforward. Reactions with oxygen and with sulfur are less so. 

Many organo-derivatives of the Group Vb elements have been prepared. The substituted phosphines, arsines, and stibines (for example, CH3PH2, (CH3)2AsH, and (CH3)sSb) are, like their parent hydrides (p. 253), easily flammable, toxic, and only weakly basic toward H4. However, the fully substituted arsines and phosphines form surprisingly stable adducts with salts of univalent gold, divalent platinum and palladium,... 

Of the group VB elements, tt complexes have been reported only for vanadium. The complexes (diolefin)V(CO)2(C6H5) obtained by UV irradiation of V(CO)4(C5H5) with butadiene, 2,3-dimethylbutadiene, and 1,3-cyclohexadiene have been reviewed earlier (219, 268). 

Cleavages of carbon-group-VB element bonds to give organolithiums occur with yields of C HsLi (X, yield)i N, 25 P, 64 As, 76 Sb, 62%. Usually, the Li salt of the group-VB element is the desired product, and the organolithium is a byproduct ... 

Compounds of the Typical Elements 10.2.6. Reactions at a Group VB Element Center 10.2.6.1. Introduction... 

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