SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF SINGLY, DOUBLY, AND TRIPLY BRIDGED DERIVATIVES OF HEXACHLOROCYCLOTRIPHOSPHAZENE WITH BIS(2-HYDROXYETHYL) ETHER AND 2,2-DIMETHYLPROPANE-1,3-DIOL

Abstract

The reactions of hexachlorocyclotriphosphazene, N3P3Cl6 (1), with 2,2-dimethylpropane-1,3-diol (2), and bis(2-hydroxyethyl) ether (3) have been previously reported. Although both reactions gave the expected spiro, ansa, and bridged type products, open-chain and triply bridged derivatives from both systems and singly bridged derivatives from 2,2-dimethylpropane-1,3-diol (2) were not isolated, and doubly bridged compounds were only detected in trace amounts in both systems. However, in a subsequent reinvestigation in tetrahydrofuran (THF) solution, the reaction of 1 with the diols 2 and 3 gave the open chain compounds N3P3Cl5[O(CH2)(2)CMe2OH] (4) and N3P3Cl5[(OCH2CH2)(2)OH] (5), the singly bridged compound N3P3Cl5[(OCH2)(2)-CMe2]N3P3Cl5 (6), the doubly bridged compounds N3P3Cl4[(OCH2)(2)CMe2](2)N3P3Cl4 (8) and N3P3Cl4[(OCH2CH2)(2)O](2)N3P3Cl4 (9), and the triply bridged compounds N3P3Cl3[(OCH2)(2)-CMe2](3)N3P3Cl3 (10) and N3P3Cl3[(OCH2CH2)(2)O](3)N3P3Cl3 (11). The doubly bridged derivatives were also isolated in better yields relative to earlier reports. The substituted cyclotriphosphazenes have been characterized by elemental analysis, mass spectrometry, as well as by H-1, P-31, and C-13 NMR spectroscopy. It is found that with variation of the solvent there is a decrease in the product formed by intramolecular reactions (spiro and ansa derivatives) and a concomitant increase in the amount of products formed by intermolecular reactions (singly, doubly, and triply bridged derivatives) of cyclophosphazene.