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 °C for 3 h to produce α-octaalkyltetrakis(tetrathiafulvaleno)phthalocyanines (8a) and (8b), respectively. The structure of the products was determined by 1H NMR, FAB MS, and MALDI TOF MS. The 1H NMR measurement was performed in chloroform-d at around 55 °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.