Phosphorus structure

Structure Identical atoms attached directly to phosphorus Structure Identical atoms attached directly to phosphorus... 

Coordination behavior of 2,5-dimethyl-4-phosphino-[l,2,3]diazaphosphole as potential multifunctional ligand has been investigated for complexation with a variety of metal centers. Despite the presence of three possible coordination sites, coordination takes place via exocyclic phosphino phosphorus (Structure 5) [81-83, 115],... 

The white and black phosphorus structures have been observed also in metastable arsenic modifications. 

All these compounds are close to spherical in shape (several of them show plastic-phase behavior), and are literally coated with valence-shell electron pairs, which make them potential multiden-tate donors. Although many of them have been known for over a century, it was not until 1965 that the first coordination adduct of a doso-phosphorus structure, P 05[(Ni(00)3] 1 (Figure 1) was reported (28). 

R. R. Holmes, Pentacoordinated Phosphorus—Structure and Spectroscopy (ACS Monograph, No. 175), American Chemical Society, Washington, DC, 1980, pp. 1-48. 

The stereoselectivity of the HWE olefination reaction depends on the nature of the RO groups on phosphorus, structural features of the ylide, the solvent, and the reaction temperature. Generally, the HWE reactions give preferentially the more stable fran -disubstituted olefins. 

Two distinct phosphorus structures, 373 and 374, are reported to be potent inhibitors of endothelin-converting enzyme and neutral endopeptidase. The latter compound is also a potent inhibitor of angiotensin-converting enzyme. 

Holmes, R. R. Pentacoordinated Phosphorus--Structure and Spectroscopy, American Chemical Society Washington, DC, 1980 Vol. I, ACS Monograph No. 175, and references cited therein. 

In pentacoordinate TBP phosphorus structures, a similar relationship is observed, although bond strengthening is relatively less significant (CNDO/2 calculations). 

Phosphines and phosphites are readily oxidized by ozone (81). The 1 1 adducts have pentacovalent phosphorus structures (82). Ozonides are reductively cleaved by triphenylphosphine (83). 

PhOSphinitGS and PhOSphonitGS. In common with phosphines these classes of phosphorus structures have unshared electron pairs on the phosphorus. They tend to be unstable to oxidation and are good metal binders. Consequently, they have been prepared as antioxidant scavengers, catalyst ligands, and ion-extraction reagents, but no commercial applications of polymeric phosphinites or phosphonites are known. 

The two-dimensional structure of monoclinic EUP7 is characterized by 6-membered P rings in chair form with equatorial connection in one direction. The structure was said to be a derivative of the GeS (or black phosphorus) structure (v. Schnering et al., 1976). 

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