Cobaltacarborane–phthalocyanine conjugates: Syntheses and photophysical properties

摘要

Syntheses of two new cobaltacarborane–phthalocyanine conjugates, one anionic (Pc >6) and one zwitterionic (Pc >7), were accomplished via cyclotetramerization of the corresponding cobaltacarborane-substituted phthalonitriles (>4 or >5) with excess phthalonitrile in quinoline. X-ray structures of two phthalonitrile precursors (>2 and >3) were obtained and are discussed, and the absorption and emission properties of the two cobaltacarborane–phthalocyanine conjugates in several solvents were investigated. The anionic conjugate >6 exists mainly as a monomer in polar organic solvents and has fluorescence quantum yields in the region 0.2–0.3. The zwitterionic conjugate >7 aggregates in solution and displays lower quantum yields ~0.1 in organic solvents.