Photophysical properties of an unusual bichromophoric species constructed from a cyclometalated Pt(ii) chromophore and a blue Bodipy-acetylacetonate species

2014 ◽  
Vol 43 (47) ◽  
pp. 17647-17658 ◽  
Author(s):  
Francesco Nastasi ◽  
Fausto Puntoriero ◽  
Scolastica Serroni ◽  
Sebastiano Campagna ◽  
Jean-Hubert Olivier ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Singlet State ◽  
Photophysical Properties

Complex 1 exhibits a formally forbidden energy transfer from the metal-based triplet to the fluorescent Bodipy singlet state.

Meso-meso phenyl bridged unsymmetrical porphyrin dyads: synthesis, spectral, electrochemical and photophysical properties

2011 ◽  
Vol 15 (01) ◽  
pp. 83-98 ◽  
Author(s):  
Meesala Yedukondalu ◽  
Dilip K. Maity ◽  
Mangalampalli Ravikanth
Keyword(s):  
Energy Transfer ◽  
Energy Level ◽  
State Energy ◽  
Singlet State ◽  
Structural Information ◽  
Photophysical Properties ◽  
Electronic Energy ◽  
Electronic Interaction ◽  
Hybrid Functional ◽  
Donor And Acceptor

Seven phenyl bridged meso-meso unsymmetrical porphyrin dyads containing two different porphyrins either two types of heteroporphyrins or one porphyrin and one heteroporphyrin were synthesized by coupling of readily accessible appropriate mono-meso porphyrin boronate/heteroporphyrin boronate with meso-bromoheteroporphyrin in the presence of Cs2CO3/Pd(PPh}3)4 in toluene/DMF at 80°C for 4 h. The dyads are freely soluble in common organic solvents and were characterized by mass, NMR, absorption, electrochemical and fluorescence techniques. The NMR, absorption and electrochemical studies indicated that the two porphyrin sub-units in dyads interact weakly and they retain their characteristic features. In six out of seven dyads, the free-base porphyrin with N4 core or its Zn(II) derivative possess singlet state energy level at higher energy hence acts as energy donor and the heteroporphyrin sub-unit with N3S , N2SO and N2S2 cores having singlet state energy level at lower energy acts as energy acceptor. Our preliminary photophysical studies on six unsymmetrical porphyrin dyads indicated a possibility of energy transfer at singlet state from donor porphyrin sub-unit to acceptor porphyrin sub-unit on selective excitation of donor porphyrin sub-unit. To gain the structural information and to demonstrate possible electronic interaction between the donor and acceptor porphyrin sub-units, DFT calculations were carried out on dyads 1, 3 and 5 by adopting B3LYP hybrid functional with Gaussian atomic basis functions. The theoretical studies predicted a considerable modification of electronic energy levels in these dyads with the change of porphyrin core in acceptor sub-unit. Calculations also indicate most efficient donor → acceptor energy transfer in case of dyad 5 supporting the experimental results.

Synthesis and Photophysical Properties of a Conformationally Flexible Mixed Porphyrin Star-Pentamer

2009 ◽  
Vol 62 (7) ◽  
pp. 692 ◽  
Author(s):  
Toby D. M. Bell ◽  
Sheshanath V. Bhosale ◽  
Kenneth P. Ghiggino ◽  
Steven J. Langford ◽  
Clint P. Woodward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Fluorescence Decay ◽  
High Yield ◽  
Free Base ◽  
Time Resolved ◽  
Zinc Porphyrin ◽  
Relative Contribution ◽  
Synthetic Strategy ◽  
Decay Times

The synthesis of a porphyrin star-pentamer bearing a free-base porphyrin core and four zinc(ii) metalloporphyrins, which are tethered by a conformationally flexible linker about the central porphyrin’s antipody, is described. The synthetic strategy is highlighted by the use of olefin cross metathesis to link the five chromophores together in a directed fashion in high yield. Photoexcitation into the Soret absorption band of the zinc porphyrin chromophores at 425 nm leads to a substantial enhancement of central free-base porphyrin fluorescence, indicating energy transfer from the photoexcited zinc porphyrin (outer periphery) to central free-base porphyrin. Time-resolved fluorescence decay profiles required three exponential decay components for satisfactory fitting. These are attributed to emission from the central free-base porphyrin and to two different rates of energy transfer from the zinc porphyrins to the free-base porphyrin. The faster of these decay components equates to an energy-transfer rate constant of 3.7 × 109 s–1 and an efficiency of 83%, whereas the other is essentially unquenched with respect to reported values for zinc porphyrin fluorescence decay times. The relative contribution of these two components to the initial fluorescence decay is ~3:2, similar to the 5:4 ratio of cis and trans geometric isomers present in the pentamer.

scholarly journals Synthesis and photophysical properties of Ir(iii)/Re(i) dyads: control of Ir→Re photoinduced energy transfer

2016 ◽  
Vol 45 (28) ◽  
pp. 11568-11579 ◽  
Author(s):  
Suad T. Saad ◽  
Alexander J. Metherell ◽  
Elizabeth Baggaley ◽  
Michael D. Ward
Keyword(s):  
Energy Transfer ◽  
Photophysical Properties ◽  
Bridging Ligand

The extent of Ir→Re photoinduced energy transfer in Ir(iii)/Re(i) dyads can be controlled using a solvent-sensitive conformationally flexible bridging ligand.

scholarly journals Spectral properties and photophysics of arylacetylenes in thin films

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Rebecca Flamini ◽  
Benedetta Carlotti ◽  
Anna Spalletti ◽  
Assunta Marrocchi
Keyword(s):  
Thin Films ◽  
Energy Transfer ◽  
Singlet State ◽  
Excited Singlet ◽  
Acetylene Derivative ◽  
Time Resolved ◽  
Homogeneous Surface ◽  
Blend Films ◽  
J Aggregates ◽  
Emitting Species

AbstractWe report the photobehaviour of a series of eight structurally related arylacetylene derivatives, in solution as well as in pristine and PC61BM blended thin-_lms. The formation of both H- and J-aggregates in the solid state have been demonstrated, and, interestingly, an energy transfer from H-aggregates or/and from residual "unstacked" molecules to J-aggregates has been found, the latter being the only emitting species. The fuorescence quenching by PC61BM at di_erent loadings has been studied in blend films, and it has been found particularly effcient in the case of a symmetrical peripheral substitution of the acetylene derivative core. Preliminary time-resolved measurements in emission (ns resolution) and in absorption (fs resolution) con_rmed the H⟶J energy transfer and underlined the presence of delayed fuorescence from Jaggregates, formed by energy transfer from the long-lived first excited singlet state of H-aggregates. In all cases, a homogeneous surface morphology of thin films.

scholarly journals Charge separation and energy transfer in multicomponent porphyrinic arrays

2001 ◽  
Vol 73 (3) ◽  
pp. 421-424 ◽  
Author(s):  
Lucia Flamigni
Keyword(s):  
Energy Transfer ◽  
Charge Separation ◽  
Photophysical Properties ◽  
Photoinduced Charge Separation ◽  
Recent Activity ◽  
Photoinduced Charge

An overview of the recent activity of the laboratory in the determination of the photophysical properties of porphyrinic arrays, with emphasis on the theme of photoinduced charge separation, is presented.

A new type of triphenylamine based coumarin–rhodamine hybrid compound: synthesis, photophysical properties, viscosity sensitivity and energy transfer

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105387-105397 ◽  
Author(s):  
Shantaram Kothavale ◽  
Nagaiyan Sekar
Keyword(s):  
Energy Transfer ◽  
Phenyl Ring ◽  
Photophysical Properties ◽  
The Other ◽  
Hybrid Compound ◽  
Compound Synthesis ◽  
New Type ◽  
Molecular Skeleton

A series of novel core modified triphenylamine coumarin–rhodamine systems (compounds MCMR, MCDR and DCMR) was designed and synthesized by incorporating a coumarin moiety on one and a rhodamine moiety on the other phenyl ring of the triphenylamine molecular skeleton.

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