Syntheses of novel non-aggregated binuclear phthalocyaninato vanadyl complexes using a palladium-catalyzed cross-coupling reaction

Novel soluble binuclear vanadylphthalocyanines linked by terminal diacetylene bridges, such as 1,4-bis{2′-[23″-(1″,2″,3″,4″,8″,9″,10″,11″,15″,16″,17″,18″-dodecakis-(2,2,2-trifluoroethoxy)phthalocyaninyl)]ethynyl}benzene divanadyl complex, 4,4′-bis{2″-[23-(1,2,3,4,8,9,10,11,15,16,17,18-dodecakis(2,2,2-trifluoroethoxy)phthalocyaninyl)]ethynyl}- benzophenone divanadyl complex and 3,6-bis{2′-[23″-(1″,2″,3″,4″,8″,9″,10″,11″,15″,16″,17″,18″-dodecakis(2,2,2-trifluoroethoxy)phthalocyaninyl)]ethynyl}-9-tetradecylcarbazole divanadyl complex, were synthesized using a palladium-catalyzed, cross-coupling reaction between the corresponding terminal diacetylenes and an excess of 23-iodo-1,2,3,4,8,9,10,11,15,16,17,18-dodecakis(2,2,2-trifluoroethoxy)phthalocyaninato vanadyl complex. A mononuclear vanadylphthalocyanine with a conjugated carbazole moiety namely, vanadyl 23-(2′-(6″-nitro-9″-tetradecyl-3″-carbazolyl)ethynyl)-1,2,3,4,8,9,10,11,15,16,17,18-dodecakis(2,2,2-trifluoroethoxy)phthalocyaninate, was also prepared for comparison. All target phthalocyanines were separated by common column chromatography and characterized by elemental analysis, IR and 1 H-NMR, UV–visible and fast-atom-bombardment mass spectroscopies. Their UV–visible absorption spectra in solution showed that the target phthalocyanine dimers were non-aggregated compounds.