| dc.contributor.author | Spence, Rupert Edward von Haken. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:41Z | |
| dc.date.available | 1991 | |
| dc.date.issued | 1991 | en_US |
| dc.identifier.other | AAINN64449 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55184 | |
| dc.description | The reactions and products of tetracoordinate phosphoryls and tricoordinate phosphoryls (phosphoranes) with various reagents, particularly the group 13 trihalides, are examined to gain a better understanding of the bonding within the phosphoryl systems and to explore their potential as precursors to the tricoordinate phosphonium (phosphoryl cation) centre. | en_US |
| dc.description | The Lewis acid-base complexes R$\sb3$PnCh.EX$\sb3$ (R = Ph or NMe$\sb2$; Pn = P or As; Ch = O or S; E = B, Al or Ga; X = F, Cl or Br) have been comprehensively examined both in solution and the solid state. The oxophosphoryl derivatives are found to have novel linear P-O-E (E = Al and Ga) frameworks while the thio and seleno phosphoryl and arsenyl systems have "typical" bent geometries. Together with a literature review, the results permit the coordinative bonding modes of the chalcogenophosphoryls to be classified into two general categories. | en_US |
| dc.description | Reaction of (R$\sb2$N)$\sb2$P(Cl)Ch (R = Me, Et or $\sp{\rm i}$Pr; Ch = NPh, O, S or Se) with AlCl$\sb3$ is found to give Lewis acid-base complexes or ionic products dependent on R, Ch and whether the products are examined in solution or the solid state. The thermodynamically most stable ionic product is found to be a dicationic P$\sb2$Ch$\sb2$ heterocycle. There is no evidence, as previously suggested, for the involvement of a tricoordinate phosphonium centre in these systems. Addition of AgSO$\sb3$CF$\sb3$ to (R$\sb2$N)$\sb2$P(Cl)NPh gives a oxophosphoryl centre, demonstrating a kinetic stabilisation for the recently prepared methylenephosphonium cation. | en_US |
| dc.description | Finally, ((Me$\sb3$Si)$\sp{\rm t}$BuN) ($\sp{\rm t}$BuN)PS and ((Me$\sb3$Si)$\sb2$N) $\sb2$P(Cl)S both give novel PNSiS heterocycles on reaction with ECl$\sb3$ (E = Al or Ga). The results are supportive of a common tricoordinate phosphonium intermediate and the PNSiS heterocycles are found to be thermodynamically unstable with respect to alternative PNSiN rings. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1991. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Inorganic. | en_US |
| dc.title | Tetra- and tri- coordinate phosphoryl systems. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
