The coordination chemistry of porphyrins has traditionally involved the ability of the porphyrin's tetrapyrrolic core to accommodate metal ions of varying charges and sizes, and on the organometallic chemistry of the resulting metalloporphyrins. However, the organometallic chemistry of porphyrins is not necessarily restricted to the metal bound in the porphyrin core, but can also be extended to the porphyrin periphery, be it through direct metalation of the porphyrin macrocycle at the meso or position, or by attachment to or merger of the porphyrin skeleton with ligands, followed by metalation. This Review focuses on the synthetic strategies used for porphyrins with peripheral metal-carbon bonds. The exciting results that have been produced underscore the importance and future potential of this field.

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Merging porphyrins with organometallics: synthesis and applications.

A Ru(II) complex (Ru) containing as ligands a tridentate 4‘-p-tolyl-2,2‘:6‘,2‘‘-terpyridine (ttpy) and a tridentate 2,6-bis(4‘-phenyl-2‘-quinolyl)pyridine (bpqpy) has been covalently linked to a porphyrin module (PH2) to obtain a PH2−Ru dyad. The corresponding PZn−Ru dyad has then been obtained by metalation of the free base porphyrin with Zn(II) acetate. The photoinduced processes which occur on excitation of the PH2−Ru and PZn−Ru dyads, as well as of the PH2 and PZn porphyrin units and the [Ru(ttpy)(bpqpy)]2+ model compound Ru, have been investigated in butyronitrile rigid matrix at 77 K and fluid solution at 295 K. In both dyads at low temperature, the lowest singlet excited state of the porphyrin moiety (S1) is quenched by energy transfer to give the triplet metal-to-ligand charge-transfer excited state of the Ru complex (3MLCT) which, in its turn, is quenched by energy transfer to yield the triplet excited state of the porphyrin moiety (T1). At room temperature, a charge-transfer (CT) excited state c...

Photoinduced Processes in Dyads Made of a Porphyrin Unit and a Ruthenium Complex

Microwave-assisted synthesis and reverse saturable absorption of phthalocyanines and porphyrins

We report new polychromophoric complexes, where different porphyrin (P) derivatives are covalently coupled to a redox active Mo center, MoL*(NO)Cl(X) (L* is the face-capping tridentate ligand tris(3,5-dimethylpyrazolyl) hydroborate and X is a phenoxide/pyridyl/amido derivative of porphyrin). The luminescence quantum yields of the bichromophoric systems (1, 2, and 5) were found to be an order of magnitude less than those of their respective porphyrin precursors. Transient absorption measurements revealed the formation of the porphyrin radical cation species (P•+) and photoinduced electron transfer from the porphyrin moiety to the respective Mo center in 1, 2, and 5. Electrochemical studies showed that the reduction potentials of the acceptor Mo centers in a newly synthesized pyridyl derivative (2; E1/2[MoI/0] = ∼ −1.4 V vs Ag/AgCl) and previously reported phenoxy- (1; E1/2[MoII/I] = ∼ −0.3 V vs Ag/AgCl) and amido- (3; E1/2[MoII/I] = ∼ −0.82 V vs Ag/AgCl) derivatives were varied over a wide range. Thus, stu...

Physicochemical and Photophysical Studies on Porphyrin-Based Donor−Acceptor Systems: Effect of Redox Potentials on Ultrafast Electron-Transfer Dynamics

Die Koordinationschemie der Porphyrine dreht sich vornehmlich um den Einbau von Metallionen unterschiedlicher Ladung und Grose in den Tetrapyrrolkern, um Metalloporphyrine mit neuen Eigenschaften zu erhalten. Eine Organometallchemie der Porphyrine muss sich aber nicht zwangslaufig auf das im Porphyrinkern gebundene Metallion beschranken, sondern sie kann sich auch auf die Molekulperipherie erstrecken: Der Porphyrinmakrocyclus kann durch direkte Metallierung in meso- oder β-Stellung modifiziert oder aber mit Liganden verknupft werden, die anschliesend eine Metallierung eingehen. Dieser Aufsatz beschreibt Synthesestrategien fur Porphyrine mit Metall-Kohlenstoff-Bindungen in der Molekulperipherie. Die beachtenswerten Ergebnisse, die hierbei erzielt wurden, heben die Bedeutung dieses Forschungsgebiets hervor und zeigen Perspektiven auf.

Porphyrine mit metallorganischen Gruppen: Synthese und Anwendungen

Synthesis, Photochemistry, and Molecular Structures of Peripherally-Molybdenated Tetraphenylporphyrins and -metalloporphyrins

Picosecond laser spectroscopy measurements on the novel complexes [Mo(NO)(L)Cl(Etpp)][Etpp = 5-(E-substituted phenyl-10,15,20-triphenylporphyrin; L = hydrotris(3,5-dimethylpyrazol-1-yl)borate, E =para-O, meta-O, ortho-O; para-NH] indicate that the observed fluorescence quenching in these compounds is due to fast (τ < 30 ps) intramolecular charge separation to produce transient species with lifetimes in the range 120–290 ps.

Stephan M. Hubig

Papers

Synthesis, Photochemistry, and Molecular Structures of Peripherally-Molybdenated Tetraphenylporphyrins and -metalloporphyrins

Intramolecular electron transfer in peripherally metallated tetraphenyl porphyrin derivatives containing molybdenum mononitrosyl redox centres