Phosphine, molecular structure

Examine both pyramidal and planar forms for each of the above molecules amine, phosphine and sulfoxide). Assume that the lower and higher-energy forms con-espond, respectively, to the preferred molecular structure and the transition state for configuration inversion. 

Like gold, silver readily forms insoluble (yellow) thiolates [Ag(SR)] primary alkylthiolates are thought to have non-molecular structures but with bulky tertiary alkyls (n = 8), probably having a cyclic structure. Addition of excess thiolate leads to the formation of clusters like Ag6(SPh)g, Ag5(SPh)7 and Ag5(SBu )6 (phosphine adducts are known, too). 

The iridium phosphine complex [IrC PEt,),] 39b can also activate O-H bonds of carboxylic acids. The stoichiometric reaction with a,(o-alkynoic acids RC=C(CH2)2 CO2H (R = Me, Ph) gave cis-hydrido(carboxylato)iridium(III) complexes 92 (Eq. 6.26), and the molecular structure of 92a was determined crystallographically [59]. 

The latter case has been demonstrated with the reaction of [ReCl3(PPh3)2(CH3CN)] with a large excess of sodium diethyldithiocarbamate which results in sulfur abstraction and in the formation of a mixed phosphine/diethyldithiocarbamato/r/ -thiocarbamoyl complex. For the molecular structure of this compound see formula (225) which represents that of the corresponding rhe-nium(IV) cation which is formed by oxidation of the primarily formed Re complex and contains one rhenium-carbon bond. The formation of thiocarbamoyl compounds seems to be an essential... 

With iodine, the imidazol-2-ylidenes (IV) form stable adducts (Scheme 8.22), in which the carbene clearly acts as a basic a donor, just like a tertiary phosphine. Interestingly, the molecular structure of this adduct may be considered as an isolated transition state that models the nucleophilic attack of the carbene on the iodine molecule. 

Figure 10.13 Two different views ofthe molecular structure of39. Hydrogen atoms a, b) and phenyl groups ofthe phosphines (a) are omitted for clarity.

The molecular structure of 1 is illustrated in figure 1 [6]. Cluster consists of six Cu and six Te centers that are shielded with a phosphine and aryl organic shell. 

Reactions of limited proportions of amine and phosphine Lewis bases with non-molecular copper and silver halides generate crystalline cubanes. Crystallographic determinations of molecular structure have been reported for at least 31 complexes with cf or d10 metal configurations, spanning the following types or homologous series of compounds. Compilations of data occur in references 157, 158 and 167. 

Figure 5 31P and "B NMR data for the ethenyl-bridged phosphine-boranes 40g and 40h and molecular structure of 40h. 

Figure 58 Molecular structure of the phosphine-borane metallocene 161a.

Figure 3.47 Molecular structures of various bidentate phosphine ligands.

Alyea, E.C., Dias, S.A., Ferguson, G. and Restivo, R.J. (1977) Structural studies of steric effects in phosphine complexes. Synthesis and crystal and molecular structure of the dinitrato (tricyclohexylphosphine)mercury(II) dimmer. Inorg. Chem., 16, 2329. 

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