Studies on Preparation and Characterization of Phthalocyanines with the Trithiole Rings

用正戊醇锂处理3,6-二烷基-4,5-（邻二甲苯-二硫代）邻苯二腈，以中等产率制备了1,4,8,11,15,18,22,25-辛烷基- 2,3,3,9,10,16,17,23,24 -四烷基（邻二甲苯-二硫代）酞菁（1a,b）[烷基=丁基和辛基]。用Li/THF/NH_3还原脱除1a、b中的4个邻二甲苯基团，生成的辛硫酸阴离子与单质硫反应，经过相应的酞菁（2a、b）的部分脱硫和缩环反应，得到具有4个三硫环的新酞菁（3a、b）。用^1H NMR和MALDI-TOF ms测定了酞菁的结构。在紫外-可见光谱中，1a，b的q波段在λ <max>=770 nm附近有吸收，而3a，b的q波段在相对蓝移的区域附近有吸收。在浓硫酸中测定3b的紫外可见光谱，其q波段λ <max>值为887 nm (log ε=4.5)，表明3b上产生的正电荷对酞菁骨架的π共轭作用有强烈影响。SbCl_5处理3b后，ESR谱呈一个增宽信号。

1,4,8,11,15,18,22,25-Octalkyl-2,3,9,10,16,17,23,24-tetrakis(o-xylylene-dithio)phthalocyanines (1a,b) [alkyl=butyl and octyl] were prepared in moderate yields on treatment of 3,6-dialkyl-4,5-(o-xylylenedithio)-phthalonitriles with lithium in n-pentanol. Reductive removal of four o-xylylene groups from 1a,b was performed with Li/THF/NH_3,and octathiolate anions generated were then reacted with elemental sulfur to give new phthalocyanines (3a,b) with four trithiole rings, respectively, after partial desulfurization and ring contraction reactions of corresponding phthalocyanines (2a,b). The structures of phthalocyanines were determined with ^1H NMR and MALDI-TOF MS. The absorption of the Q-band of 1a,b was observed at around λ_<max>=770 nm in the UV-vis spectra, while that of 3a,b was found at around a relatively blueshifted region. When the UV-vis spectrum for 3b was measured in concentrated sulfuric acid, the λ_<max> value of the Q-band was 887 nm (log ε=4.5), which suggests that the positive charge generated on 3b strongly affects the π-conjugation of the phthalocyanine skeleton. The ESR spectrum was observed as one broadening signal on treatment of 3b with SbCl_5.