Collect. Czech. Chem. Commun. 1988, 53, 61-67

Optical and voltammetric studies on tetraphenylethylene salts

Mahboob Mohammad, Tariq Mahmood, Tahir Jamil and Ather Yaseen Khan

Electrochemistry Group, Chemistry Department, Quaid-Azam University, Islamabad, Pakistan


Optical spectra of tetraphenylethylene salts with lithium, potassium, rubidium, and tetrabutylammonium as counter ions, were recorded in tetrahydrofuran. Also the optical spectrum of sodium salt of tetraphenylethylene was recorded at very high dilution. On computer resolution of the optical spectra it was found that the observed bands were composed of three peaks, located around 385, 490, and 585 nm. Depending upon the counter ions and the environments these occur in different height ratios. These findings pointed to ion pairs formation and helped in elucidating their structure. The cyclic voltammetric studies on tetraphenylethylene helped in the evaluation of dissociation constant of T2-, M+ and the disproportination constant 2T.- ⇄ T2- + T. The former was found to be 1.2 . 10-5 mol 1-1, the latter 0.42 in dimethylformamide.