Donor acceptor interactions in polymeric systems, 3. Oligoesters from 9‐[1,1‐bis(hydroxymethyl)ethyl]carbazole

Abstract

Abstract Oligoesters having a 9‐carbazolyl group attached to the main chain were prepared by oligocondensation of 9‐[1,1‐bis(hydroxymethyl)ethyl]carbazole ( 2a ) with diethyl malonate, dimethyl terephthalate, and diethyl 2‐(carbazol‐9‐yl)‐2‐methylmalonate ( 1 ). Charge transfer complex formation of these oligoesters and their monomeric model compound with 2,4,7‐trinitrofluorenone was investigated by means of absorption spectroscopy. The stability constants ( K ) of the oligomeric systems were always larger than those of the monomeric systems. The magnitude of K was found to be in the following order: oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxy‐(2‐carbazol‐9‐yl‐2‐methyl)‐malonyl] ( 3c ) ≫ oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxymalonyl] ( 3a ) ≈ oligo[oxy‐(2‐carbazol‐9‐yl‐2‐methyl)trimethyleneoxyterephthaloyl] ( 3b ) >9‐[1,1‐bis‐(acetoxymethyl)ethyl]carbazole ( 2b ). Fluorescence spectroscopy of these carbazolyl derivatives in dilute solutions indicate the environmental difference of chromophors.