The invention relates to compounds of formula I: ##STR00001## ##STR00002## x+y+z=1 and x=0 to 1, y=0 to 1, z=0 to 1 and R is CH.sub.3 or CF.sub.3 and R.sup.1 and R.sup.2 each represent H or a functional group. These compounds show promise in films and as optical waveguide materials as well as bimodal interference coupler and arrayed waveguide grating demultiplexer materials.