Optical Properties of Polymers: Model Calculations for Dinucleoside Phosphates

The optical properties (absorption, polarizability, circular dichroism, and optical rotatory dispersion) are calculated for models of dinucleoside phosphates using the time‐dependent Hartree theory with a simple free‐electron monomer model. Detailed results over the entire frequency spectrum have been obtained for a variety of dimer and polymer structures. The relation between the following conformational effects and the resulting polymer optical properties were determined: base stacking and unstacking, helical winding and unwinding, and changes in distance between monomer planes. In addition, several other optical effects were calculated: the relative contributions of nearest and nonnearest neighbors along an infinite helical polymer; the effect of band half‐width on the observable splitting; and the relation between monomer and polymer line shape. The calculated results predict reasonable quantitative values as well as the main qualitative features of the experimental dinucleoside phosphate and polyribo...