Templatkontrollierte Synthese eines π‐konjugierten Porphyrin‐Nanorings

Hoffmann, Markus; Wilson, Craig J.; Odell, Barbara; Anderson, Harry L.

doi:10.1002/ange.200604601

Cited by 73 publications

(24 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The synthesis of these compounds have been reported previously. [19,50] Spectroscopy: Absorption spectra were measured on a Cary 4B UV/Vis spectrophotometer. The spectra were recorded between 300 and 850 nm at 300 nm per min with 0.5 nm spectral bandwidth.…”

Section: Methodsmentioning

confidence: 99%

Control of Electron Transfer in a Conjugated Porphyrin Dimer by Selective Excitation of Planar and Perpendicular Conformers

Winters

Kärnbratt

Blades

et al. 2007

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

A donor-acceptor system is presented in which the electron-transfer rates can be sensitively controlled by means of excitation wavelength and temperature. The electron donor is a butadiyne-linked zinc porphyrin dimer that is connected to a C(60) electron acceptor. The broad distribution of conformations allowed by the butadiyne linker makes it possible to selectively excite perpendicular or planar donor conformers and thereby prepare separate initial states with driving forces for electron transfer that differ by almost 0.2 eV. This, as well as significant differences in electronic coupling, leads to distinctly different rate constants for electron transfer, which in consequence can be controlled by changing excitation wavelength. By extending the system with a secondary donor (ferrocene), a second, long-range charge-separated state can be formed. This system has been used to test the influence of conformational heterogeneity on electron transfer mediated by the porphyrin dimer in the ground state. It was found that if the dimer is forced to a planar conformation by means of a bidentate ligand, the charge recombination rate increased by an order of magnitude relative to the unconstrained system. This illustrates how control of conformation of a molecular wire can affect its behaviour.

show abstract

Section: Methodsmentioning

confidence: 99%

Control of Electron Transfer in a Conjugated Porphyrin Dimer by Selective Excitation of Planar and Perpendicular Conformers

Winters

Kärnbratt

Blades

et al. 2007

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…[7] Size-exclusion chromatography in the presence of 1,4-diazabicyclo- Previously, we reported that the template is displaced from our porphyrin[8] nanoring with pyridine. [5] However, pyridine does not displace the template from 1 a·3 and 1 b·3, even when the complexes are dissolved in neat pyridine ([pyridine] = 12.4 m). More strongly coordinating amines, such as quinuclidine do displace the template from these complexes, when used in large excess ([quinuclidine] > 0.4 m ; 250 000 equiv).…”

Section: Dedicated To Professor Jeremy Sanders On the Occasion Of Hismentioning

confidence: 99%

Enhanced π Conjugation around a Porphyrin[6] Nanoring

et al. 2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…The similar EM values of T6 and T6* probably accounts for their remarkably similar abilities to direct the synthesis of c-P6. The lower effective molarity measured in c-P7·T7* is close to the value previously measured for an 8-porphyrin nanoring complex, c-P8·T8 (EM ¼4 m), [3] and probably reflects the increase in flexibility with increasing molecular size, as well as the flexible À(CH 2 ) 2 À links in T7*. The lower cooperativity in c-P7·T7* must contribute to the lower yield in the template-directed synthesis of c-P7.…”

mentioning

confidence: 58%

“…[1] The introduction of flexibility into a multivalent ligand generally reduces its affinity for a complementary receptor, but the energy cost of restricting conformational freedom can be surprisingly small. [2] Recently we have shown that rigid radial oligo-pyridine templates can be used to direct the synthesis of complementary zinc porphyrin nanorings, [3][4][5] and that the nanoring-template complexes can have huge stability constants (up to 10 36 m À1 ). [3,4,6] Herein we report an investigation of flexible chiral templates based on cyclodextrin cores.…”

mentioning

confidence: 99%

Cyclodextrin‐Templated Porphyrin Nanorings

et al. 2014

View full text Add to dashboard Cite

a-and b-Cyclodextrins have been used as scaffolds for the synthesis of six-and seven-legged templates by functionalizing every primary CH 2 OH with a 4-pyridyl moiety. Although these templates are flexible, they are very effective for directing the synthesis of macrocyclic porphyrin oligomers consisting of six or seven porphyrin units. The transfer of chirality from the cyclodextrin templates to their nanoring hosts is evident from NMR and circular dichroism spectroscopy. Surprisingly, the mean effective molarity for binding the flexible a-cyclodextrin-based template within the six-porphyrin nanoring (74 m) is almost as high as for the previously studied rigid hexadentate template (180 m). The discovery that flexible templates are effective in this system, and the availability of a template with a prime number of binding sites, open up many possibilities for the template-directed synthesis of larger macrocycles.

show abstract

Templatkontrollierte Synthese eines π‐konjugierten Porphyrin‐Nanorings

Cited by 73 publications

References 37 publications

Control of Electron Transfer in a Conjugated Porphyrin Dimer by Selective Excitation of Planar and Perpendicular Conformers

Control of Electron Transfer in a Conjugated Porphyrin Dimer by Selective Excitation of Planar and Perpendicular Conformers

Enhanced π Conjugation around a Porphyrin[6] Nanoring

Cyclodextrin‐Templated Porphyrin Nanorings

Contact Info

Product

Resources

About