The invention relates to compounds of formula I wherein R1, R2, and R4 are independently at each occurrence a C1-C20 aliphatic radical, a C3-C20 aromatic radical, or a C3-C20 cycloaliphatic radical; R3 and R5 are independently at each occurrence hydrogen, a C1-C20 aliphatic radical, a C3-C20 aromatic radical, or a C3-C20 cycloaliphatic radical; and a, b and d are independently 0 or an integer ranging from 1 to 3. The invention further relates to polymers derived from compounds of formula I. The polymers may be polyesters, polyethers, polycarbonates, polyestercarbonates, polyetherketones, or polyethersulfones. Compounds and polymers of the invention find use in light emitting devices.