Phosphorus and Tin

Compounds with Sn-P bonds are generally less stable to heat and to oxidation than their Si-P or Ge-P analogues. Tin has a greater tendency than these other elanents to achieve five- or six-coordination. Trimethylstannyl phosphine can be made as in 

Some alkyl or phenylstannyl phosphines can be prepared from the appropriate phosphine and alkyl or phenyl tin compound. Many are ring or cage compounds and they are structural analogues 

6Me2SnH2 + 2P4 4PH3 + (Me2Sn)gP4 5Me2SnH2 + P4 2PH3 + (Me2Sn)5P2 + 2H2 

Larger cages built from Sn and P atoms are known. 

If the cyclic trimer (9.316) is heated, pentameric phenylphosphine is obtained (9.326). Like their silicon and germanium analogues, stannyl phosphines are easily hydrolysed (9.327), or oxidised to phosphinates (9.328). The P-Sn bond is broken by alkyl halides as in Equation 9.329. 

---

The methods available for synthesis have advanced dramatically in the past half-century. Improvements have been made in selectivity of conditions, versatility of transformations, stereochemical control, and the efficiency of synthetic processes. The range of available reagents has expanded. Many reactions involve compounds of boron, silicon, sulfur, selenium, phosphorus, and tin. Catalysis, particularly by transition metal complexes, has also become a key part of organic synthesis. The mechanisms of catalytic reactions are characterized by catalytic cycles and require an understanding not only of the ultimate bond-forming and bond-breaking steps, but also of the mechanism for regeneration of the active catalytic species and the effect of products, by-products, and other reaction components in the catalytic cycle. 

Horton and Aubrey (34) handpicked pure vitrain samples from coals and separated them into five different specific gravity fractions. They then analyzed these for 16 minor elements. They concluded that for the three vitrains they studied, beryllium, germanium, vanadium, titanium, and boron were contributed almost entirely by the inherent (organically combined) mineral matter and that manganese, phosphorus, and tin were associated with the adventitious (inorganically combined) mineral matter. 

P. Jolibois considers that only tin triphosphide and tritetritaphosphide are chemical individuals and that the other phosphides which have been reported are solid soln. or mixtures. A. C. Vivian found that when a mixture of phosphorus and tin is heated in sealed tubes, two conjugate soln. appear to be formed, and two definite layers of molten liquid are present. The maximum amount of phosphorus alloying with tin is 8 per cent., and the product melts at about 485° ... 

When phosphorus and tin are melted together in a sealed tube, two liquid layers are formed, and the maximum amount of phosphorus taken up by the tin is 8 per cent.,4 while by heating tin and phosphorus in a sealed tube at 620° C. for 10 hours grey crystals were obtained which contained 40 per cent, of phosphorus and which after purification by hydrochloric acid, alkali and nitric acid had the composition SnP3.6 The density was 4-1 at 0° C. Alloys of tin with about 13 per cent, of phosphorus contained Sn4P3,5-6 which had a density of 5-18 and was attacked by aqueous acids. 

Thietane is a superior inhibitor of corrosion of iron in 10% hydrochloric acid and its effectiveness is said to be due to partial polymerization on the surface of the iron. Addition of chloride ion reduces the inhibition, possibly by inducing ringopening with the formation of sulfhydryl groups. The cyclic sulfide also has been considered as an odorant for natural gas and its absorption by organic soil and clay have been determined. Stabilization of methylchloroform and trichloroethylene by thietane, 2-methylthietane, 3-hydroxythietane, and two spirothietane derivatives has been claimed. Phosphorus and tin derivatives of 3,3-bis-hydroxy-methylthie-tane are reported to be light stabilizers for poly(vinyl chloride), and the dibutyl-tin derivative is a catalyst for the polymerization of aliphatic isocyanates. Mercury and zinc compounds derived from phenylmercury or phenylzinc hydroxide and 3-... 

Tabte 7. Sn NMR parameters of compounds with tin-phosphorus and tin-arsenic bonds."... 

Nuclear magnetic resonance and mass spectrometric studies on the novel ring system (26) indicate that there is intramolecular co-ordination between the phosphorus and tin atoms... 

Use the periodic table to write the electron configuration for phosphorus and tin. SOLUTION... 

H. Kwart and K. G. King (1977) d-Orbitals in the chemistry of Silicon, Phosphorus and Tin (Springer-Verlag, Berlin, Heidelberg, New York). 

Figure 11. Impact fracture surface of an Fc/3%Ni steel with phosphorus and tin segregated to the grain boundaries.

Figure 12. Auger spectrum from the grain boundary surface of the Fe/.l 7fNi steel with phosphorus and tin grain boundary segregation.

Figure 14. The secondary-electron image of the fracture surface of the Fe/3%NM steel with phosphorus and tin segregated to the grain boundaries (a) together with (b) the imaging XPS tin 3t/s/2 map 44. ...

---