Synthesis and Characterization of Side Group–Modified Cyclotetraphosphazene Derivatives

Two novel cyclotetraphosphazene derivatives were synthesized by the reaction of octachlorocyclotetraphosphazene with the potassium salt of 4-hydroxybenzaldehyde, and subsequent reduction of aldehyde groups to alcohol groups using sodium borohydride. The bromination reaction was carried out using PBr3 to give N4P4(OC6H4-p-CH2Br)8 (4). This compound was employed in reaction with imidazole or morpholine to produce eight-armed, star-branched title compounds. The target compounds were characterized by 1H, 31P, and 13C NMR as well as IR and ESI-MS. The Cu complex of 5a was effective in oxidative cleavage reactions. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.