TY - JOUR T1 - Spectrophotometric Study of Charge-Transfer Complexes of DDQ with Some Benzophenones in Chloroform Solution TT - مطالعه اسپکتروفتومتری کمپلکس انتقال بار دی دی کیو با تعدادی از بنزوفنونها در محلول کلروفرم JF - jsci JO - jsci VL - 18 IS - 58 UR - http://jsci.khu.ac.ir/article-1-1138-en.html Y1 - 2004 SP - 56 EP - 66 KW - DDQ KW - Benzophenones KW - Charge-transfer complex KW - spectrophotometry N2 - A spectrophotometric study concering the charge transfer interaction between 2,3-dichloro-5,6-dicyano-1,4-benzoquione (DDQ) and some benzophenoes has been carried out in chloroform at 25°C. Comparision of the spectra of the complexes of 1.2-dimethoxybenzene-DDQ and benzophenone-DDQ is indicative of two kinds of transitions: (i) n→π*, and (ii) π→π* respectively,). Formation constants of the resulting 1:1 molecular complexes were determined by using the Hildebrand method. The values of formation constants are in parallel with the charge density on the oxygen atoms of cabonyl groups. Also steric hindrance of substituents affects the stability of the resulting complexes. The shifts in stretching frequency of carbonyl groups of benzophenones, brought about upon complexation, further supports that donation takes place from oxygens of the carbonyl groups. M3 ER -