Download or read book Synthesis and Electron charge Transfer Properties of Linked Donor acceptor and Individual Donor acceptor Systems Involving Tetrathiafulvalene and Paraquat Units written by Yana Bykov and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Studies of AzaBODIPY Derived Donor Acceptor Systems for Light Induced Charge Separation written by Melissa A. Collini and published by . This book was released on 2018 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficiency and mechanism of electron- and energy transfer events occurring in both in natural and synthetic donor-acceptor systems depend on their distance, relative orientation, and the nature of the surrounding media. Fundamental knowledge gained from model studies is key in building efficient energy harvesting and optoelectronic devices. Faster charge separation and slower charge recombination in donor-acceptor systems is often sought out. In our continued effort to build donor-acceptor systems using near-IR sensitizers, in the present study, we report ground and excited state charge transfer in newly synthesized, directly linked, tetrads featuring bisdonor (donor = phenothiazine and ferrocene), BF2-chelated azadipyrromethane (azaBODIPY) and C60 entities. The tetrads synthesized using multi-step synthetic procedure revealed strong charge transfer interactions in the ground state involving the donor and azaBODIPY entities. The near-IR emitting azaBODIPY acted as a photosensitizing electron acceptor along with fullerene while the phenothiazine and ferrocene entities acted as electron donors. The triads (bisdonor-azaBODIPY) and tetrads revealed ultrafast photoinduced charge separation leading to D•+-azaBODIPY•--C60 and D•+-azaBODIPY-C60•- (D = phenothiazine or ferrocene) charge separated states from the femtosecond transient absorption spectral studies in both polar and nonpolar solvent media. The charge separated states populated the triplet excited state of azaBODIPY prior returning to the ground state.
Download or read book Donor acceptor Bond written by Elena Nikolaevna Gurʹi︠a︡nova and published by John Wiley & Sons. This book was released on 1975 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Electron Donor acceptor Subphthalocyanine Derivatives and Porphyrin Metal Complexes written by Lakshmi Chockalingam Kasi Viswanath and published by . This book was released on 2013 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multicomponent electron-donor acceptor systems incorporating supramolecules such as porphryins, phthalocyanines, subphthalocyanines, and perylenes have gained utmost importance in various fields of optoelectronics. Subphthalocyanines are unique, non-planar, aromatic supramolecules which have recently emerged as a platform for novel electron acceptors as they show great potential in photosynthetic systems. Subphthalocyanine is an excellent electron acceptor, when covalently linked to other electron donor species through the axial substitution and executes fast photoinduced electron transfer. The axial approach to a synthesis is advantageous in the sense that the electronic characteristics of the subphthalocyanine macrocyle are preserved. Subphthalocyanine derivatives prepared in this study are expected to have outstanding tunable properties for the development of artificial photosynthetic systems and various molecular electronic devices. This dissertation will center on the synthesis, characterization of various donor-acceptor conjugates of subphthalocyanine.
Download or read book Synthesis of Selected Electron Donors and Acceptors and Study of Inter intramolecular Electron Transfer from Ruthenium II Complexes in Solution Frozen Matrix and Silica Aerogels as the Basis for Optical Devices written by Abdel Monem Mohammad Rawashdeh and published by . This book was released on 2003 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Harvesting energy from the sun is something that nature does well through photosynthesis: green plants convert carbon dioxide to glucose with energy provied by the sun in a complex set of reactions. Mimicking photosynthesis through artificial systems designed to convert optical energy into chemical or electrical energy, has been the goal and challenge for many years ... the photochemical and photophysical properties of transition metal complexes, especially [Ru(bpy)3]2, have been studied comprehensively in terms of the Photoinduced Electron Transfer (PET) properties in donor-acceptor systems (D/A)."--Introduction, p. 1.
Download or read book Ultrafast Photoinduced Energy and Electron Transfer Studies in Closely Bound Molecular and Nanocarbon Donor Acceptor Systems written by Habtom Berhane Gobeze and published by . This book was released on 2018 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the study, photosynthetic system constructs based on BF2-chelated dipyrromethene (BODIPY), BF2-chelated azadipyrromethene (AzaBODIPY), porphyrin, phthalocyanine, oxasmaragdyrin, polythiophene, fullerene (C60), single-walled carbon nanotube and graphene are investigated. Antenna systems of BODIPY dyads and oligomers having BODIPY as an excitation energy donor connected to different acceptors including BODIPY, azaBODIPY, oxasmaragdyrin and aluminum porphyrin are studied. Different synthetic methodologies are used to afford donor-acceptor systems either directly linked with no spacer or with short spacers of varying length and orientation. The effect of donor orientation, donor optical gap as well as nature of donor-acceptor coupling on the donor-acceptor spectral overlap and hence the rate of excitation energy transfer is investigated. In all these systems, an ultrafast energy transfer followed by electron transfer is observed. In particular, in a directly connected BODIPY-azaBODIPY dyad an unusually ultrafast energy transfer (̃ 150−200 f̧ ' ) via F©œrster mechanism is observed. The observation of energy transfer via F©œrster instead of Dexter mechanism in such closely coupled donor-acceptor systems shows the balance between spatial and electronic coupling achieved in the donor-acceptor system. Moreover, in donor-acceptor systems involving semiconducting 1D and 2D materials, covalently functionalized single-walled carbon nanotubes via charge stabilizing (TPA)3ZnP and noncovalently hybridized exfoliated graphene via polythiophene chromophores are studied for their charge transportation functions. In both cases, not only an ultrafast charge transfer in the range of (̃ 2−5 p̧ ' ) is observed but also the charge-separated states were long lived implying the potential of these functionalized materials as efficient charge transporting substrates with organic chromophores for photovoltaic and optoelectronic applications where ultrafast intercomponent charge transfer is vital. In addition, as a final part of this dissertation, the mechanisms of electron injection and back electron transfer in heterogeneous systems involving supramolecularly anchored high potential chromophores on TiO2 film are studied by femtosecond transient absorption spectroscopy. In this study, not only are important insights gained on the utilization of supramolecular anchoring of chromophores such as porphyrins, phthalocyanines, and their perflorinated high potential analogues, chromophores currently showing promise as highly efficient sensitizers in dye sensitized solar cells, on TiO2 film but also on the effect of anchor length and sensitizer orientation on the rates of electron injection and back electron transfer at the sensitizer-TiO2 interface.
Download or read book Photoinduced Intramolecular Charge Transfer in Donor Acceptor Biaryls and Resulting Applicational Aspects Regarding Fluorescent Probes and Solar Energy Conversion written by Michael Maus and published by Universal-Publishers. This book was released on 1998 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is focused on the effects of photoinduced intramolecular charge transfer (CT) in three differently twisted donor-acceptor (D-A) biphenyls. Taking into account a further pair of differently twisted D-A biaryls new universal insights into the photoinduced electronic and conformation dynamics of D-A biaryls are obtained. Furthermore, possible applications in fields of solar energy conversion and fluorescence sensing of microenvironments are demonstrated. Experimental means of stationary and time-resolved (ps to s) luminescence, transient absorption (sub-ps), polarization spectroscopy, high pressure and low temperature techniques are employed in conjunction with quantum chemical calculations. Twist angle and solvent dependent electron transfer (ET) interactions between the D and A aryl moieties are responsible for the low lying and solvatochromic intramolecular CT electron band which gains unusually high intensity through strong electronic coupling of the pure 1ET with the ground (S0) and 1La state. As regards the class of biaryl compounds, for the first time, an excited state electron transfer from the D to the A could be monitored by dual spectrally separated stimulated fluorescence bands with precursor-successor relationship on a sub-ps timescale for the D-A biphenyls. It is concluded that, in additon to the electronic interaction of 1ET with S0 and 1La, the electronic interaction with a close lying 1Lb state plays a fundamental role in the ET dynamics and the 1CT-S0 transition probability in D-A biaryls. The initial photoinduced conformational relaxation occurs towards planarity in all biaryls investigated. However, various results evidence that the highly twisted D-A biphenyl additionally performs a slow "excited state intramolecular back twist rotation" leading to a solvent polarity dependent conformational equilibrium between a more planar (CT) and a more twisted (CTR) conformer in S1(1CT). Using global analysis of the biexponential fluorescence decays as a function of temperature and pressure in medium polar solvents, the kinetics, thermodynamics, viscosity control and decomposed emission spectra associated with this adiabatic photoreaction are determined. The twist angle dependent ability of the D-A biphenyls to serve as fluorescent probes of micropolarity, changes of microviscosity or matrix order, protic solvents and pH is investigated. In particular, fluorescence sensing of pH seems to be promising.
Download or read book Studying the Properties of Conjugated Donor Acceptor Complexes with Naphthaleneimide Acceptors and Dialkoxybenzene Donors Linked by a Triple Bond written by Eleanor Lee Pate and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Electronic Properties of TTFAQ Based Donor acceptor Molecular Systems written by Guang Chen and published by . This book was released on 2006 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge Transfer in Linked Donor chromophore acceptor Systems written by Steven L. Larson and published by . This book was released on 1994 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Donor Acceptor Organic Polymers by Click Type Cycloaddition Retroelectrocyclization Reaction written by Wenyi Huang and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ,Äúclick,Äù type cycloaddition/retroelectrocyclization reaction is an intriguing approach for synthesizing electron donor-acceptor organic polymers. This chapter covers the fundamental reaction mechanism and the basic principles of applying this reaction to the synthesis of organic polymers via postfunctionalization or step-growth polymerization. The electron donor-acceptor moieties can be incorporated into the main-chain and/or side-chain of both conjugated and nonconjugated polymers. These polymers feature attractive properties including intramolecular charge-transfer bands, nonlinear optical properties, redox activities, third-order nonlinear optical properties, and enhanced thermal stability. Because of this, these polymers have found a variety of applications such as colorimetric chemosensors of metal ions, nonlinear optics, and solar cells. This novel ,Äúclick,Äù chemistry paves a unique path toward the synthesis of next-generation functional materials that cannot be accomplished by the incumbent synthetic methods.
Download or read book Charge transfer Dynamics in Molecular Donor acceptor Systems and Heterostructures written by Robin Döring and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge Transfer in Photofunctional Electron Donor acceptor Systems written by Matthias König and published by . This book was released on 2014 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Transfer in Donor Bridge acceptor Systems written by Mattijs Koeberg and published by . This book was released on 2001 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optoelectronic Properties Ground and Excited State Dynamics and Synthesis of Strongly Coupled Porphyrin based Donor acceptor Systems written by Steven M. LeCours and published by . This book was released on 1996 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electron Donor Acceptor Interaction in Chiral Molecules Stereospecific Synthesis of N aralkyl pyridinium Ions and Their Spectroscopic Properties written by Anton Johannes de Gee and published by . This book was released on 1973 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Describing Charge Transfer in Extended Donor Acceptor Systems with Density Functional Theory written by Andreas Karolewski and published by . This book was released on 2013 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
