Porphyrins pyridine

Ligand self-assembly through coordinative bonding has been used to increase the bulkiness of a monodentate tris-3-pyridyl phosphine ligand employing the zinc porphyrin/pyridine interaction (Scheme 33) [95-97]. The corresponding rhodium catalyst allowed for regioselective hydroformylation of2-octene [95]. 

Pyridine V-oxides have also received attention due to their catalytic properties, for example, they have been used as Lewis bases in aldol reactions <05JOC5235, 05SL2388>. Maikov and co-workers elaborated on the use of pyridine V-oxides as a catalyst for allylation of aldehydes with allyltrichlorosilanes <05OL3219>. Additionally, Higuchi et al. report a highly reactive Ru porphyrin/pyridine V-oxide system that shows unique reactivity for the oxidation of various... 

Table 9.1 Fractions of Zn-porphyrin-pyridine complex 1-2/(i-2) formed on-chip at three residence time values.

Higuchi, T. and M. Hirobe (1996). Four recent studies in cytochrome P450 modelings A stable iron porphyrin coordinated by a thiolate ligand a robust ruthenium porphyrin-pyridine N-oxide derivatives system polypeptide-bound iron porphyrin application to drug metabolism smdies. J. Mol. Catal A Chem. 113, 403 22. 

The luminescence quenching for CdSe/ZnS nanocrystals passivated by organic ligands (pyridyl-substituted porphyrins, pyridine, 2,2 -bipyridine, 1,10-phenathroline) has been studied on the basis of steady-state and time resolved measurements in toluene at 295 K. The porphyrin Jt-conjugated macrocycle plays the principal role in non-radiative exciton relaxation in NC-organic ligand composites (via mesomeric effects and possible partial HOMO and LUMO overlap of porphyrin and meso-pyridyl rings). 

Figure 2 (A) Intramolecular H-bond formed In a zinc porphyrin—pyridine complex and (B) the Intermolecular H-bond used as the reference system/ ...

Figure 8 Distribution of (A) thermodynamic effective molarity (EM) values for noncova-lent bond formation in supramolecular complexes (data for intramolecular H-bond formation in zinc porphyrin—pyridine complexes plotted separately as DMC) and (B) kinetic and (C) thermodynamic EM values for covalent bond formation.

Figure 12 (A) Anderson s zinc porphyrin—pyridine complex which has a very high binding affinity (Kf = 1.3 x 10 M ) and (B) the reference system (Ar are solubilizing groups).

Fiunter determined the values of EM in toluene and in 1,1,2,2-tetrachloroethane (TCE) for intramolecular H-bond formation in a large number of zinc porphyrin—pyridine complexes. " " Fig. 16... 

Figure 16 Comparison of the values of effective molarity (EM) measured in toluene with the values in 1,1,2,2-tetrachloroethane for intramolecular H-bond formation in Hunter s zinc porphyrin—pyridine complexes. The dashed line corresponds to log EM(TCE) = log EM(toluene).

Donor p), 216-217, 219f Double mutant cycle pMC), 81—82 zinc porphyrin—pyridine complex, 83f Double-strand cleavage via single C4 -radical, 157—158... 

In their work on cooperative multipoint binding interactions, Hunter and coworkers used calorimetry to determine the association constant for certain zinc(ll) porphyrin-pyridine complexes (Figure 5). The reason why... 

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