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Title: Solvent Effects in Aminolysis Reactions of Some Chlorocyclophosphazenes.
Author: Yu, H. S.
Awarding Body: Birkbeck (University of London)
Current Institution: Birkbeck (University of London)
Date of Award: 1975
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The reactions of hexachlorocyclotriphosphazatriene, N3P3C16' with diethylamine have been investigated. Nine diethylaminoderivatives, N3P3C16_n(NEt2)n (n==1,2,2,3,3,3,4,4 or 6) were - - obtained after purification of complex reaction mixtures by either gas-liquid chromatography or fractional crystallisation. Assignment of structures to the chlorodiethylaminocyclotriphosphazatrienea was baaed on their methyl proton n.m.r. spectra. The reactions of the hexachloride, N3P3C16, with 4, 6 or 8 equivalents of diethylamine in various solvents, namely, acetonitrile, ethyl acetate, xylene and benzene were monitored by gas-liquid chromatography. A variation in relative yield of products in different reaction solvents was observed. In particular, aromatic solvents appear to favour the formation of the geminal tris- derivative, N3P3C13(NEt2)3. Comparisons are a180 made with the analogous reactions of the hexachloride with the secondary amines, dimethylamine, piperidine and pyrrolidine. A colourless crystalline compound, geminal N3P3C12(NEt2)3OH was isolated from some reactions of the hexachloride with diethylamine in benzene. Spectroscopic evidence indicates that this hydroxy derivative probably exists in its tautomeric form, N3HP3(O)C12(NEt2)3. An attempt to prepare the analogous dimethylamino- compound was unsuccessful although the, reaction of geminal N3P3C13(NMe2)3 with potassium hydroxide and water in boiling ethanol, gave a geminal (iii) ethoxy- derivative, N3P3C12(NMe2)3(OEt). ' Reactions of 2,2,4,4-tetrachloro-6,6-diphenyl-cyclotriphosphazatriene, N3P3Ph2C14' with diethylamine in benzene and also in acetonitrile have been studied. The di-substituted structure. No other bisdiethylamino- isomer was detected. Reactions of the ring contracted compound, 2,2,4,4-tetrachloro- 6-phenyl-(2',2',2'-triphenylphosphazen-l'-yl)cyclotriphosphazatriene, N3P3Ph(N=PPh3)Cl4' with dimethylamine and diethylamine gave the mono-r N3P3Ph (N = PPh3)Cl3.NMe2 and N3P3Ph(N=PPh3)Cl3.NEt2] and bisamino- derivatives [N3P3Ph(N= PPh3 )Cl2 (NMe2) 2 ,and N3P3Ph (N:: PPh3 )Cl2 (NEt2) 2 ] , the biscompounds have a geminal structure. A sealed tube reaction gave the fully substituted derivatives. Similar reactions of 2,2,6,6-tetrachloro-4,4,8,8-tetra- 'phenylcyclotetraphosphazatetraene, N4P4Ph4Cl4' with dimethylamine in acetonitrile or xylene gave the mono- (N4P4Ph4Cl3.NMe2), the geminal bis- [N4P4Ph4C12(NMe2)2] and the tetrakisdimethylamino- [N4P4Ph4(NMe2)4J derivatives •
Supervisor: Not available Sponsor: Not available
Qualification Name: Doctoral Thesis - University of London. Qualification Level: Doctoral
EThOS ID:  DOI: Not available