Preparation and electrochemical and optical properties of α-octaalkylphthalocyanines with four fused TTF units

3,6-Dialkylphthalonitriles (6a) and (6b) with a fused TTF unit at 4,5-positions were prepared from dialkyltetrabromobenzenes via five step reactions (alkyl: butyl and octyl). Compounds 6a and 6b were treated with lithium in n-hexanol at 120 degrees C for 3 h to produce alpha-octaalkyltetrakis-(tetrathiafulvaleno)-phthalocyanines (8a) and (8b), respectively. The structure of the products was determined by H-1 NMR, FAB MS, and MALDI TOF MS. The H-1 NMR measurement was performed in chloroform-d at around 55 degrees C because of their higher aggregative property. Electrochemical and optical properties of 8a and 8b were examined by cyclic voltammetry and UV-vis and MCD spectroscopy. Molecular orbital calculations succeeded in reproducing the observed absorption spectrum of tetrakis(tetrathiafulvaleno)phthalocyanine.