EFFECTIVE CONJUGATION LENGTH AND UV VIS SPECTRA OF OLIGOMERS/

On the basis of an extended series of monodisperse oligomers of the di alkoxy-substituted phenyleneethenylenes 1a-i the Eqs. (3) and (4) were conceived in order to determine the limiting values of the energies E i and the wavelengths lambda(i) of the UV/vis absorption. The converge nce of the E-i and lambda(i) values with a growing number n of repeati ng units permits a precise prediction of the E-i,E-infinity and lambda (i,infinity), values of the corresponding polymer 1j as well as a stat ement about the overall effect of conjugation Delta E-i and the effect ive conjugation length ECL. A great variety of different conjugated ol igomers 2-14 can be evaluated by the same algorithm.