No abstract

No abstract

No abstract

Science and Engineering Research council of Canada for financial support of this research and to Bruker Spectrospin (Canada) Ltd. for the use of the AM400, AM300, and AC200 spectrometers located in their Milton (Ontario) laboratories. Registry No. (Sodium acrylate)(N,N'-methylenebis(acry1- References and Notes(1) Bovey, F. A.; Mirau, P. A.ABSTRACT A copolymer of maleic anhydride (MAn) and 2-isopropenylnaphthalene (%I€") has been prepared and found to be water soluble over a wide pH range. The copolymer composition has been determined to be dependent upon the monomer feed ratio in a manner suggesting a 1:l alternating sequence distribution. The fluorescence spectrum exhibits monomer and excimer emissions at high pH and shifts dramatically over the pH range 5-3 to a nearly pure excimer spectrum. At high pH, the excimer emission is ascribed to nearest-neighbor naphthalenenaphthalene diads which are present in small quantities as 'defects". Excitation spectra and 77 K fluorescence spectra demonstrate that this static excimer component persists for all pHs, and dynamic excimer component arises upon acidification. This is attributed to the collapse of the coil structure as the acid groups are neutralized. Experiments utilizing an environmentally sensitive optical probe (l& anilinonaphthalene sulfonate) supported this picture as did anthracene sensitization and copper(II) quenching studies. It is proposed that electronic energy transport between chromophores is efficient, especially at low pH. Dynamic light scattering studies gave evidence for polymer aggregation at high concentration.

No abstract