Excitational energy and photoinduced electron transfer reactions in Ge(IV) corrole–porphyrin hetero dimers

Giribabu, Lingamallu; Kandhadi, Jaipal; Kanaparthi, Ravi Kumar; Reeta, P. Silviya

doi:10.1016/j.jlumin.2013.08.009

Cited by 18 publications

(14 citation statements)

References 47 publications

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“…The simple and efficient procedure of corrole synthesis, combined with the pre-tuning of physical and chemical characteristics by varying the peripheral substituents [ 5 , 6 , 7 , 8 ], central metal [ 6 , 9 , 10 ], and axial ligands [ 11 , 12 ], has revived substantial interest in employing these contracted porphyrinoids in various fields. A wide range of applications has been reported: corroles are used in dye-sensitized solar cells [ 9 , 13 ], as photosensitizers in photodynamic therapy and photodynamic detection [ 14 , 15 , 16 , 17 ], for the photodynamic inactivation of mold fungi and green algae [ 18 , 19 ], for regular and sophisticated optical imaging [ 20 , 21 ], for the formation of singlet oxygen for catalysis [ 22 , 23 , 24 ] and for corrole-based electron and energy transfer systems [ 25 , 26 , 27 ]. Since many of the processes involving corroles proceed via transient paramagnetic states, revealing the mechanisms and parameters of these states as well as identifying their reaction pathways is central to the optimized application of corroles [ 8 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ].…”

Section: Introductionmentioning

confidence: 99%

Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

et al. 2017

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Corroles are a developing class of tetrapyrrole-based molecules with significant chemical potential and relatively unexplored photophysical properties. We combined femtosecond broadband fluorescence up-conversion and fs broadband Vis-pump Vis-probe spectroscopy to comprehensively characterize the photoreaction of 5,10,15-tris-pentafluorophenyl-corrolato-antimony(V)-trans-difluoride (Sb-tpfc-F2). Upon fs Soret band excitation at ~400 nm, the energy relaxed almost completely to Q band electronic excited states with a time constant of 500 ± 100 fs; this is evident from the decay of Soret band fluorescence at around 430 nm and the rise time of Q band fluorescence, as well as from Q band stimulated emission signals at 600 and 650 nm with the same time constant. Relaxation processes on a time scale of 10 and 20 ps were observed in the fluorescence and absorption signals. Triplet formation showed a time constant of 400 ps, with an intersystem crossing yield from the Q band to the triplet manifold of between 95% and 99%. This efficient triplet formation is due to the spin-orbit coupling of the antimony ion.

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Section: Introductionmentioning

confidence: 99%

Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

et al. 2017

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“…21 The potentiality of stable corroles depends on their ability to display within the arrays either efficient energy or electron transfer process following light absorption. In the design of photoactive arrays, corroles can play the role of energy acceptors more easily than that of energy donors, due to their relatively low excited state energy level; examples are triphenylamine-corrole, 21 coumarin-corrole, 22 ferrocene-corrole, 23,24 phenathiazine-corrole, 25 carbazolecorrole, 26 BODIPY-corrole, 27 porphyrin-corrole, 28,29 etc. In addition, they have been employed as electron donors rather than electron acceptors, due to the relative ease of oxidation of their macrocycle, depending on the substitution pattern; as in the case of corrole-fullerene, 30 corrole-napthalimide, 31 corrole-perlynbisimide, 32 corroleanthraquinone, 33 etc.…”

Section: Introductionmentioning

confidence: 99%

Triphenylamine corrole dyads: Synthesis, characterization and substitution effect on photophysical properties

Sudhakar

Giribabu

2017

J Chem Sci

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We present our results on the effect of substitution on the photophysical properties of donoracceptor (D-A) systems in which triphenylamine is the donor and substituted corroles i.e., 5,15-phenyl-10triphenylaminecorrole TPACor 1, 5,15-di(3,5-ditertbutylphenyl)-10-triphenylaminecorrole TPACor 2, and 5,15-(4-nitrophenyl)-10-triphenylaminecorrole TPACor 3 is the acceptor. All three dyads have been characterized by elemental analysis, MALDI-MS, cyclic voltammetry, UV-Vis and fluorescence (steady state and timeresolved) spectroscopies. Both Soret and Q bands of TPACor 3 are red-shifted when compared to other two dyads due to the presence of electron withdrawing nitro group. Similarly, redox properties of TPACor 3 are altered, when correlated to TPACor 1 and TPACor 2 dyads. However, the fluorescence emission of triphenylamine in all three dyads was quenched significantly (>90%) compared to its monomeric unit. The presence of either electron releasing or electron withdrawing group on corrole moiety has not much effect on the photophysical properties. The quenched emission was attributed to intramolecular excitation energy transfer and the photoinduced electron transfer reactions contested in these dyads.

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“…[28][29][30] A few D-A systems based on corroles have been reported in the literature to understand natural photosynthetic phenomena. [31][32][33][34][35][36][37] These D-A systems have been constructed either at the meso-phenyl position or at the axial position of resident metal ion of the corrole macrocycle. For example, our group has utilized the axial position/s of the resident metal ion of the corrole macrocycle, constructed hetero oligomers and studied the effect of metal ion on PET and EET reactions.…”

Section: Introductionmentioning

confidence: 99%

“…For example, our group has utilized the axial position/s of the resident metal ion of the corrole macrocycle, constructed hetero oligomers and studied the effect of metal ion on PET and EET reactions. 31,32 Ngo et al have constructed mixed corroleporphyrin multichromophoric systems by using meso positions of the macrocycle and studied the singlet-singlet energy transfer process by using transient absorption spectroscopy. 34 D'Souza and co-workers have used meso positions of donor corrole and constructed corrole-fullerene dyads at a rate of charge separated state B10 10 -10 11 s À1 .…”

Section: Introductionmentioning

confidence: 99%

Corrole–ferrocene and corrole–anthraquinone dyads: synthesis, spectroscopy and photochemistry

Kandhadi

Venkatesh

Bangal

et al. 2015

Phys. Chem. Chem. Phys.

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Two different donor-acceptor systems based on corrole-ferrocene and corrole-anthraquinone having the 'Olefin Bridge' at the β-pyrrole position have been designed and synthesized. Both the dyads corrole-ferrocene () and corrole-anthraquinone () are characterized by elemental analysis, ESI-MS, (1)H NMR, UV-Visible, fluorescence spectroscopies (steady-state, femtosecond time-resolved), femtosecond transient absorption spectroscopy (fs-TA) and electrochemical methods. (1)H-NMR shows that two doublets at 6.50 and 7.25(δ) ppm belong to vinylic protons, which are characteristic of the formation of dyads. UV-Visible absorption spectra showed that dyads are merely superpositions of their respective constituent monomers and dominated by corrole S1 ← S0 (Q-band) and S2 ← S0 (Soret band) transitions with a systematic red-shift of both Soret and Q-bands along with the broadening of the bands. A prominent splitting of the Soret band for both the dyads is observed due to bulky substitutions at the peripheral position, which deviate from the planarity of the corrole macrocycle. Both the dyads exhibit significant fluorescence emission quenching (95-97%) of corrole emission compared to the free-base corrole monomer. Emission quenching is attributed to the excited-state intramolecular photoinduced electron transfer (PET) from corrole to anthraquinone in the dyad, whereas in the dyad it is reversed. The electron-transfer rates (kET) for and were found to be 3.33 × 10(11) and 2.78 × 10(10) s(-1), respectively. Despite their very different driving forces, charge separation (CS) and charge recombination (CR) are found to be in identical timescales.

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Excitational energy and photoinduced electron transfer reactions in Ge(IV) corrole–porphyrin hetero dimers

Cited by 18 publications

References 47 publications

Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

Ultrafast Dynamics of Sb-Corroles: A Combined Vis-Pump Supercontinuum Probe and Broadband Fluorescence Up-Conversion Study

Triphenylamine corrole dyads: Synthesis, characterization and substitution effect on photophysical properties

Corrole–ferrocene and corrole–anthraquinone dyads: synthesis, spectroscopy and photochemistry

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