Synthesis and Mesomorphic Properties of Substituted Pyrazinoporphyrazines

Efimova, S. V.; Койфман, О. И.; Bykova, V. V.; Lukyanov, I. Yu.; Sotsky, V. V.; Usol’tseva, N. V.

doi:10.1080/15421406.2011.609394

Cited by 6 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mesomorphism was assumed to originate from the thermal fluctuations due to free rotation of the bulky propeller-shaped substituents. Efimova et al reported related phthalocyanines with terminal tert -butyl groups showing lyotropic behavior in chloroform or toluene …”

Section: Classes Of Compoundsmentioning

confidence: 99%

Discotic Liquid Crystals

et al. 2015

View full text Add to dashboard Cite

Section: Classes Of Compoundsmentioning

confidence: 99%

Discotic Liquid Crystals

et al. 2015

View full text Add to dashboard Cite

“…If they are suitably substituted or coordinate specific central cations, TPyzPzs exhibit high quantum yields of singlet oxygen or fluorescence. 5 TPyzPzs can be advantageously used in various applications, such as photosensitizers for photodynamic therapy, 6 catalysts, 7 nonlinear optical materials, 8 liquid crystals 9 or crystals with large voids. 10 The presence of nitrogen atoms in the TPyzPz core imparts more electron-deficient character to the entire macrocycle compared to the parent Pcs.…”

Section: Introductionmentioning

confidence: 99%

Peripheral substitution as a tool for tuning electron-accepting properties of phthalocyanine analogs in intramolecular charge transfer

et al. 2015

View full text Add to dashboard Cite

The intramolecular charge transfer (ICT), which is a pathway for excited state relaxation, was studied on the newly synthesized zinc(ii) complexes of tetrapyrazinoporphyrazines bearing one fixed donor (i.e., a dialkylamino substituent). The rest of the peripheral substituents on the core was designed with respect to their different electronic effects (OBu, neopentyl, StBu, COOBu). The photophysical (singlet oxygen and fluorescence quantum yields) and electrochemical (reduction potentials) properties were determined and compared within the series and with compounds that did not contain a donor moiety. The ICT efficiency correlated well with both the electron-deficient character of the core and the Hammett substituent constants σp. The most efficient ICT was observed for the core with the most electron-accepting substituent (COOBu), and the lowest ICT efficiency was detected for the least electron-deficient core (substituted by OBu). Titration of DMSO solutions of target compounds with H2SO4 indicated that basicity of the azomethine bridges was largely influenced by the character of the peripheral substituents while the dialkylamino donor center remained nearly unaffected. Furthermore, protonation of the donor nitrogen caused partial restoration of the fluorescence quantum yield (increase up to 90 times) due to blocking of ICT. The results implied that the ICT efficiency was strongly dependent on the electron-accepting properties of the core whose properties can be readily affected by suitable selection of peripheral substituents.

show abstract

Phenol‐Substituted Tetrapyrazinoporphyrazines: pH‐Dependent Fluorescence in Basic Media

Novakova

Lásková

Vavřičková

et al. 2015

Chemistry A European J

View full text Add to dashboard Cite

Tetrapyrazinoporphyrazines (TPyzPzs) bearing one, two, four or eight 3,5-di(tert-butyl)-4-hydroxyphenol moieties were synthesized as zinc(II) complexes and metal-free derivatives. The deprotonation of the phenol using tetrabutylammonium hydroxide induced the formation of a strong donor for intramolecular charge transfer that switched OFF the red fluorescence (λF ∼660 nm) of the parent zinc TPyzPzs. The changes were fully reversible for TPyzPzs with one to four phenolic moieties, and an irreversible modification was observed for TPyzPzs substituted with eight phenols. The sensors were anchored to lipophilic particles in water, and a pKa approximately 12.5-12.7 was determined for the phenolic hydroxyl based on fluorescence changes in different buffers. In addition, a novel concept for fluorescence OFF-ON-OFF switching in metal-free TPyzPzs bearing phenolic moieties upon addition of specific amounts of base was demonstrated.

show abstract

Synthesis and Mesomorphic Properties of Substituted Pyrazinoporphyrazines

Cited by 6 publications

References 6 publications

Discotic Liquid Crystals

Discotic Liquid Crystals

Peripheral substitution as a tool for tuning electron-accepting properties of phthalocyanine analogs in intramolecular charge transfer

Phenol‐Substituted Tetrapyrazinoporphyrazines: pH‐Dependent Fluorescence in Basic Media

Contact Info

Product

Resources

About