Group 15 amides homoleptic

It will be immediately apparent from Tables 6.1 and 6.2 that amides of the groups 4-6 elements are by far the most numerous. Furthermore, the number of second and third row element amido derivatives of these groups approaches or exceeds those of the first row. It can also be seen that for the first row elements homoleptic amides in the highest oxidation... 

An important recent development in the area of the monodentate amido metal chemistry has come from the group of Cummins who introduced ligands of the type —N(R)Ar (for example, R = Bu , 1-adamantyl (I-Ad), 2-adamantyl (2-Ad), —C(CD3)2(CH3) Ar = Ph, C6H3Me2-3,5, C6H4F-4).These allowed the isolation of an Mo N(R)Ar 3 species having three-coordinate molybdenum as well as three-coordinate derivatives of several other metals. Apart from [M N(SiMe3)2 3] (M = Y," La), the molybdenum compounds are the only examples of structurally characterized open shell, three-coordinate homoleptic amides... 

In our 1980 book, the homoleptic Group 14 metal(ll) amides M N(R )R ]2 there reported were those with M = Ge and P R SiMe, SiEt, GeMe, GeEt,... 

Table 10.1 Some structural parameters for homoleptic Group 15 metal(lll) amides...

A monoamide complex was obtained with [OCtBu(2-CH2-NC5H3-6-Me)2] as a co-ligand (Fig. 19) [127]. The overall structure features are very similar to the aforementioned homoleptic Sm-system except that a monodentate alkoxide ligand has been replaced by a N(SiMe3)2 group. The amide group makes the complex soluble in aliphatic hydrocarbons. 

Carboxylic acid amide functionalised imidazolium salts can be reacted with group 10 halides directly in the presence of an inorganic base (e.g. K COj) to form homoleptic complexes (see Figure 4.41) [122]. Interestingly, the carbene units are cis to each other and not trans as would be expected (see Figures 4.30 and 4.38). The cis complexation is not aided by hydrogen bonding as the carboxylic acid amide functionality loses its proton upon complexation to nickel. 

Reaction of the same functionalised imidazolium salt with PdCl produced interesting results [123], In the presence of pyridine as base, the simple palladium(ll) carbene adduct was formed (see Figure 4.42), but when K COj was used as base, activation of the amide functional groups produced the corresponding homoleptic complexes, as a mixture of the cis and trans isomers. 

Carbon and oxygen impurities are below 1 atom %. Based on the gases that are eliminated from this precursor, it is clear that the nitrogen source in the deposition is the azide group. It is found that the best films are formed under vacuum without additional sources of nitrogen (such as N2 and NH3). Homoleptic indium amides can be used when volatilized in the presence of NH3 . ... 

The amido ligand is isoelectronic with the alkyl and alkoxo groups and has the possibility to exhibit N-M ir-interactions in order to stabilize the systems they form. Different synthetic reactions are used to prepare mono-Cp titanium derivatives containing amido ligands. These compounds are normally synthesized by (i) the action of the corresponding amide salt on Cp TiCl3, (ii) displacement of amine from a homoleptic amido titanium compound by a Cp reagent, (iii) dehalosilylation reactions, and (iv) elimination of alkane by reaction of an alkyltitanium compound with amine. 

In 2013, Schafer s group [22b] reported titanium bis(amidate) and bis(pyridonate) complexes for the homopolymerization of rac-lactide and e-caprolactone, and also the formation of a random copolymer of the two. These complexes form pseudo-octahedral six-coordinate species, which were characterized in the solid state. Complexes were synthesized by first installing 2 equiv. of the ligand on homoleptic TifNMe ) followed by protonolysis of dimethylamido ligands with 2 equiv. of alcohol (Figure 19). 

Compounds included in this chapter are the homoleptic amides and imides of empirical formula M(NRR ) and M(NR) , where R, R = H, alkyl, aryl or trialkylsilyl, and the mixed amido-imido compounds of formula M(NRR ) (NR). Brief mention is given to certain compounds of formula L M(NRR ) or L M(NR) , where L represents a group of ligands, neutral or anionic, which also share the coordination sphere of the metal, when the chemistry of the M—N bond is of particular note. Metal-containing compounds derived from halogen azides are not discussed. 

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