Phosphorus porphyrin

Fig. 12 List of some recent cationic phosphorus porphyrins of type 59...

Finally, phosphorus porphyrins, such as some of those detailed in Sect. 2.3.1 have attracted attention in organic chemistry for their unique photochemical properties. Aida reported that basic aqueous solutions of benzonitrile in the presence of 59a undergo under irradiation (A>420 nm) a clean transformation... 

As just mentioned, phosphorus porphyrins have unique photochemical properties. Their photophysics is also interesting. Emitter-quencher assemblies based on porphyrin building blocks have attracted attention due to their potential to serve as models in photosynthetic research (see [90] for an example) or for the development of photoswitches that could be used for the fabrication of molecular electronic/optical devices. In this context, Maiya and coworkers constructed a P(VI) porphyrin system 59b with two switchable azobenzene groups positioned in the apical positions of the pseudo-octahedral phosphorus atom [92]. Photoswitch ability (luminescence on/off) was demonstrated as... 

Fig. 22 Phosphorus porphyrin arrays with molecular conducting tetrathiophene wires...

Scheme 24 Electrochemical Polymerization of wheel-and-axle type phosphorus porphyrins...

Finally a new departure in an unusual aspect of hypervalent phosphorus chemistry has been provided by the synthesis of water-stable dialkoxy phosphorus(V)-tetraphenylporphyrins (125) from (124). The six-co-ordinate phosphorus porphyrin (125) with R=Et, has... 

A great variety of covalently or non-covalently boimd porphyrin-terpyri-dine motifs are known to closely mimic the initial photoinduced electron transfer (PET) or excitation energy transfer (EET) events of natural photosynthetic reactions. A first example of covalent connection of a terpyridine group to the axial position of a phosphorus porphyrin as in 33 (Fig. 26b) was presented by Kumar and Maiya [81 ]. The terpy moiety itself is a strong chelator towards other transition metal ions (see also 24). Upon postirradiation, the axial terpy subimits act as a donor and P(V) porphyrin as an acceptor. In fluorescence titrations it was found that the PET and EET reactions are mod-... 

Fig. 35 General structure of the phosphorus-porphyrins with axially hound phenolate-porphyrins by Maiya [81,102-104] and Tanaka and Segawa [105], M = VO(IV), Co(ll), Ni(ll), Cu(ll), Zn(ll), or P(V)...

From a general point of view, electropolymerization was performed starting from porphyrins decorated with different electropolymerizable units that permit the polymerization process to occur (see reviews on thienyl- [28], pyrrole- [29, 30] or other aryl-appended porphyrins [31, 32] and references herein). An unusual example found in literature concerns the electropolymerization of thienyl units used as ligand of a phosphorus atom complexed in the porphyrin core, this specific electropolymerization process led to one-dimensional poly thiophene wires containing phosphorus porphyrins [33]. 

Segawa H, Nakayama N, Shimidzu T (1992) Eleetroehemieal synthesis of one-dimensional Donor-Acceptor polymers containing oUgothiophenes and phosphorus porphyrins. Chem Commun 10 784—786... 

Fig. 5-24 Phosphorus porphyrins cited as templates by Shimidzu and coworkers in Reference [101]. Reproduced from Reference [101] with permission.

Borgstrom M, Blart E, Boschloo G et al (2005) Sensitized hole injection of phosphorus porphyrin into NiO toward new photovoltaic devices. J Phys Chem B 109 22928-22934... 

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