Photophysical measurements have been used to characterize a series of well-defined block copolymers labeled with aromatic chromophores and quenchers. These include measurements of (1) energy migration kinetics in the homopolymers and diblock copolymers; (2) solvent effects (CH2Cl2, THF, THF/CH3CN and CHCl3) on exciplex emission in the diblock copolymers; (3) temperature effects on the fluorescence and phosphorescence of the diblock copolymers; (4) the dependence of the efficiency of steady-state and time-resolved emission in several triblock copolymers (dicyanobenzene)(5)-(phenanthrene)(5)-(dimethylaniline)(5) on relay length (n); and (5) transient absorbance and photoinduced charge separation in these triblock copolymers as a function of relay length. A photoinduced charge separation of 7.2 mu s was achieved in a polynorbornyl triblock copolymer bearing a graded series of electron transfer relays : (dicyanobenzene)(5)-(phenanthrene)(10)-(dimethylaniline)(5).