Spectroscopic and solution properties of phenoxyphosphazene random copolymers containing optically active binaphthoxy groups

The reaction of a mixture of [NPCl2](n) and Cs2CO3 first with (R)-(+)-1,1'-binaphthyl-2,2'-diol (HO-C10H6-C10H6-OH) (binaphthol) and subsequently with phenol (HO-C6H5) in refluxing 1,4-dioxane gave the series of the optically active random copolymers {[NP(O2C20H12)](x)[NP(OC6H5)(2)](1-x)}(n) (2). Absolute molecular weight distributions and radius of gyration have been determined by size exclusion chromatography, using simultaneously multiangle light scattering and differential refractive index detectors. The dependence of the dimensions of the polymers on the molecular weight through the corresponding scaling laws is studied. In addition, a stereochemical study of homopolymers [NP(O2C20H12)](n), I and copolymers 2 based on the CD exciton chirality method is also included. The reaction of the partially substituted polymer [NP(R-O2C20H12)(0.4)(Cl-2)(0.6)](n) with the stoichiometric amount of racemic binaphthol, or with a large excess of the latter, in the presence of Cs2CO3 gave the same polymer [NP(R-O2C20H12)(0.4)- (rac-O2C20H12)(0.4)](n) [(-)-3] irrespective of the amount of racemic binaphthol used, showing no enantiomeric induction by the R-binaphthoxy units already present in the polymer.