Synthesis of near-infrared absorbed metal phthalocyanine with S-aryl groups at non-peripheral positions

Phthalocyanines are used as various applications, including as organic charge carriers in photocopiers, laser light absorbers in data storage systems, photoconductors in photovoltaic cells and electrochromic displays, and non-colored transparent film in visible region. The absorption maxima of phthalocyanines are best if moved near the infrared region for these applications. The Q band of phthalocyanines can be moved to bathochromic effects through extension of a p conjugation system such as naphthalocyanines and anthracyanines. Yields of naphthalocyanines and anthracyanines are, however, low. To solve the problem, novel metal phthalocyanines having non-peripheral S-aryl substituent were synthesized. The novel phthalocyanines show a high strain structure and no liquid crystal property. The target compounds were synthesized: 15 phthalocyanines from 2,3-dicyanohydroquinone in 3 steps via 1,2-dicyanobenzene-3,6-bis(trifluorate) and 1,2-dicyanobenzene-3,6-thiophenols. The Q bands of obtained compounds appeared in the near-infrared region. In particular, lead 1,4,8,11,15,18,22,25-octakis(thiophenylmethyl) phthalocyanine shows a Q band at 857 nm. Furthermore, non-colored transparent films in the visible region can be produced.