Cho, Y Baek, H Sohn, YS 2024-01-21T16:11:10Z 2024-01-21T16:11:10Z 2021-09-03 1999-01 0277-5387 https://pubs.kist.re.kr/handle/201004/142600 New cyclotriphosphazenes fully substituted with dicarboxylic amino acid esters (aminomalonate, aspartate and glutamate) were synthesized and characterized by means of elemental analysis, IR and multinuclear (H-1, C-13 and P-31) NMR spectroscopies, and X-ray crystallography. The rate of full substitution of hexachlorocyclotriphosphazene with the amino acid esters has been found to be largely dependent on the steric hindrance of the corresponding amino acid esters. The full substitution of the chlorotrimer with aminomalonate was completed in 6 h when the reactants were refluxed in tetrahydrofuran (THF), but the full substitution with aspartate or glutamate required more severe conditions: The substitution with aspartate was completed in 12 h by refluxing the reactants in the presence of n-Bu4NBr as the catalyst in toluene, but the substitution with glutamate could not be completed even after refluxing for more than two days in the presence of the same catalyst in toluene. To endow the above compounds with the functionality for incorporation of metal moiety, they have been hydrolyzed in aqueous solutions of alkali metal hydroxides to yield the corresponding metal salts, which can afford twelve active sites. (C) 1999 Elsevier Science Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD ORGANOMETALLIC CHEMISTRY CYCLOPHOSPHAZENES PHOSPHAZENES COORDINATION POLY(ORGANOPHOSPHAZENES) COMPLEXES POLYMERS REAGENTS Functionalization of organophosphazene trimers: synthesis and characterization of hexakis(dicarboxylic amino acid ester)cyclotriphosphazenes and their salt derivatives Article 10.1016/S0277-5387(99)00042-X 1 POLYHEDRON, v.18, no.13, pp.1799 - 1804 POLYHEDRON 18 13 1799 1804 scie scopus 000081153900002 2-s2.0-0006944496 Chemistry, Inorganic & Nuclear Crystallography Chemistry Crystallography Article ORGANOMETALLIC CHEMISTRY CYCLOPHOSPHAZENES PHOSPHAZENES COORDINATION POLY(ORGANOPHOSPHAZENES) COMPLEXES POLYMERS REAGENTS phosphazene cyclotriphosphazene cyclic trimer aminomalonate aspartate glutamate