title: Distorted fused porphyrin-phthalocyanine conjugates: synthesis and photophysics of supramolecular assembled systems with a pyridylfullerene.
abstract: In the current work, we report on the synthesis and photophysical features of supramolecular hybrid systems that are based on newly fused porphyrin-phthalocyanine (P-Pc) conjugates and a pyridylfullerene. The ZnP-ZnPc conjugate was synthesized in three steps starting with a Diels-Alder reaction between β-vinylporphyrin and fumaronitrile. The resulting mixture of isomeric adducts was then dehydrogenated to yield the corresponding benzo[b]porphyrin-2(1),2(2)-dicarbonitrile. In the final step, cyclotetramerization with 4-tert-butylphthalonitrile, in the presence of zinc acetate, afforded the bis-metalated conjugate. Selective demetallation of ZnP led to the H(2)P-ZnPc conjugate. For both conjugates steric hindrance is the inception to a bent configuration, which does, however, not preclude enlargement of the π-conjugated system, that is, the porphyrins and the phthalocyanines. The two conjugates coordinate N-(4-pyridyl)fullero[c]pyrrolidine giving rise to the corresponding supramolecular porphyrin-phthalocyanine-fullerene systems. Photophysical measurements corroborate a sequential deactivation in the excited state, namely an initial intramolecular energy transfer from ZnP or H(2)P to ZnPc followed by an intramolecular charge transfer to yield ZnP-(ZnPc)˙(+)-(C(60))˙(-) and H(2)P-(ZnPc)˙(+)-(C(60))˙(-), respectively.
authors: Universidade de Aveiro, Departamento de Química e QOPNA, 3810-193 Aveiro, Portugal.
authors: Ana M V M
authors: AM
authors: Pereira
authors: Ana R M
authors: AR
authors: Soares
authors: Anita
authors: A
authors: Hausmann
authors: Maria G P M S
authors: MG
authors: Neves
authors: Augusto C
authors: AC
authors: Tomé
authors: Artur M S
authors: AM
authors: Silva
authors: José A S
authors: JA
authors: Cavaleiro
authors: Dirk M
authors: DM
authors: Guldi
authors: Tomás
authors: T
authors: Torres