Nonlinear Optical Materials Based on Benzobisthiazole. Electronic Structure/Molecular Architecture/Polarizability/Hyperpolarizability Relationships Derived from π-Electron Theory

1987 ◽  
Vol 109 ◽  
Author(s):  
Dequan Li ◽  
T. J. Marks ◽  
M. A. Ratner
Keyword(s):  
Charge Transfer ◽  
Optical Materials ◽  
Electron Cloud ◽  
Nonlinear Optical Materials ◽  
Molecular Architecture ◽  
Electron Theory ◽  
Electron Model ◽  
Molecular Dipole ◽  
Model Hamiltonian ◽  
Donor Acceptor

ABSTRACTFactors contributing to the polarizability (αij) and frequencydoubling hyperpolarizability (βijk) of 2-(p-dimethylaminophenyl)-6-(pnitrophenyl) benzo(l,2-d:4,5-d′ )blsthiazole (DNBT) are analyzed via perturbation theory and the PPP-SCF-MECI π-electron model Hamiltonian. While the observable part of β (βvec) is clearly identifiable with a small number of charge transfer excitations along the molecular dipole direction, a (and by inference, the second-order hyperpolarizability γ) is more closely related to the overall size (volume) of the π-electron cloud. As a consequence, βvec is far more sensitive to molecular distortions which affect donor-acceptor charge transfer interactions than is π. The more sensitive frequency dependence of βvec can be understood in terms of the three-photon character of this nonlinearity.

Third-Order Optical Susceptibilities of Molecular and Polymeric Materials. Symmetry, Frequency, and Chromophore Structure Dependence as Probed by π-Electron Theory

1988 ◽  
Vol 134 ◽  
Author(s):  
D. Li ◽  
T. J. Marks ◽  
M. A. Ratner
Keyword(s):  
Perturbation Theory ◽  
Charge Transfer ◽  
Polymeric Materials ◽  
Molecular Structures ◽  
Conjugation Length ◽  
Third Order ◽  
Electron Theory ◽  
Electron Model ◽  
Structure Dependence ◽  
Model Hamiltonian

ABSTRACTThird-order optical susceptibilities (γijkl) can be efficiently analyzed for a variety of molecular structures employing perturbation theory and a PPP-SCF-SECI-DECI π-electron model Hamiltonian. The key, frequency tripling second hyperpolarizability γijkl(−3ω;ω,ω,ω) is calculated with full single and double CI. It is found that double excitations play a major role in third-order processes, and that γijkl, like the polarizability αij, is sensitive largely to the overall size (volume) of the π system, although charge transfer excitations may also contribute. The frequency dependence of v and correlations between γijkl and conjugation length are found for a series of trans polyenes.

Nonconjugatively linked donor—acceptor compounds: a new class of nonlinear optical materials

1991 ◽  
Vol 179 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
W. Schuddeboom ◽  
B. Krijnen ◽  
J.W. Verhoeven ◽  
E.G.J. Staring ◽  
G.L.J.A. Rikken ◽  
...  
Keyword(s):  
Optical Materials ◽  
Nonlinear Optical ◽  
Nonlinear Optical Materials ◽  
New Class ◽  
Donor Acceptor

Diketopyrrolopyrrole based donor–acceptor π-conjugated copolymers with near-infrared absorption for 532 and 1064 nm nonlinear optical materials

2020 ◽  
Vol 8 (37) ◽  
pp. 12993-13000
Author(s):  
Zitong Liu ◽  
Jibin Sun ◽  
Chaoxian Yan ◽  
Zheng Xie ◽  
Guanxin Zhang ◽  
...  
Keyword(s):  
Infrared Absorption ◽  
Optical Materials ◽  
Nonlinear Optical ◽  
Near Infrared ◽  
Nonlinear Optical Materials ◽  
Optical Responses ◽  
Donor Acceptor ◽  
Conjugated Copolymers

Diketopyrrolopyrrole based donor–acceptor π-conjugated copolymers with smaller bandgaps exhibit more excellent broadband (532 and 1064 nm) nonlinear optical responses.

scholarly journals Role of intramolecular hydrogen bonds in promoting electron flow through amino acid and oligopeptide conjugates

2021 ◽  
Vol 118 (11) ◽  
pp. e2026462118
Author(s):  
Rafał Orłowski ◽  
John A. Clark ◽  
James B. Derr ◽  
Eli M. Espinoza ◽  
Maximilian F. Mayther ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Hydrogen Bonds ◽  
Electron Flow ◽  
Intramolecular Hydrogen Bonding ◽  
Electronic Coupling ◽  
Molecular Architecture ◽  
Energy Flows ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Intramolecular Hydrogen

Elucidating the factors that control charge transfer rates in relatively flexible conjugates is of importance for understanding energy flows in biology as well as assisting the design and construction of electronic devices. Here, we report ultrafast electron transfer (ET) and hole transfer (HT) between a corrole (Cor) donor linked to a perylene-diimide (PDI) acceptor by a tetrameric alanine (Ala)4. Selective photoexcitation of the donor and acceptor triggers subpicosecond and picosecond ET and HT. Replacement of the (Ala)4 linker with either a single alanine or phenylalanine does not substantially affect the ET and HT kinetics. We infer that electronic coupling in these reactions is not mediated by tetrapeptide backbone nor by direct donor–acceptor interactions. Employing a combination of NMR, circular dichroism, and computational studies, we show that intramolecular hydrogen bonding brings the donor and the acceptor into proximity in a “scorpion-shaped” molecular architecture, thereby accounting for the unusually high ET and HT rates. Photoinduced charge transfer relies on a (Cor)NH…O=C–NH…O=C(PDI) electronic-coupling pathway involving two pivotal hydrogen bonds and a central amide group as a mediator. Our work provides guidelines for construction of effective donor–acceptor assemblies linked by long flexible bridges as well as insights into structural motifs for mediating ET and HT in proteins.

Molecule-Based Approaches to High-Performance Second-Order Polymeric Nonlinear Optical Materials. Properties of Ultra-high-Tg Chromophoric Polyimides and Polyureas.

1995 ◽  
Vol 392 ◽  
Author(s):  
Jia-Fu Wang ◽  
Lifeng Geng ◽  
Weiping Lin ◽  
Tobin J. Marks ◽  
George K. Wong
Keyword(s):  
Optical Materials ◽  
High Performance ◽  
Nonlinear Optical ◽  
Second Order ◽  
Nonlinear Optical Materials ◽  
Materials Properties ◽  
Donor Acceptor ◽  
Test Current ◽  
Diallylbisphenol A ◽  
Aging In Air

AbstractThis contribution describes the synthesis and properties of three classes of model NLO chromophore-functionalized high-Tg polymers which test current ideas about architecture-Tg- χ(2) performance relationships. Condensation of bismaleimides with diallylamino-functionalized donor-acceptor chromophores yields polable matrices with Tg values as high as 325°C and χ(2) responses as high as 0.7 × 10-7 esu (27 pm/V; λohigh as 0.7 × 10-7 esu (27 pm/V; λo = 1064 nm; 1.17 eV). Likewise, = 1064 nm; 1.17 eV). Likewise, condensation of o,o'-diallylbisphenol A with bismaleimides followed by chromophore functionalization yields an analogous series of polyimides with Tg values as high as 260°C and χ(2) response as high as 1.0 × 10-7 esu (42 pm/V at λo = 1064 nm). Polymerization of a bis(4-aminophenyl)lophine chromophore with bismaleimides or diisocyanates yields polymers with Tg values as high as 350°C and χ(2) = 0.62 × 10-7 esu (25 pm/V at λo = 1064 nm). All members of the above series exhibit minor to negligible decay in χ(2) response on aging in air at 100°C for 1000 h. The lophine-based material exhibits only ∼10% χ(2) decay on aging for 100 h at 200 °C under N2.

Structure-Property Relationships in Organic Nonlinear Optical Materials

1999 ◽  
Vol 561 ◽  
Author(s):  
Eric M. Breitung ◽  
Robert J. McMahon
Keyword(s):  
Bond Length ◽  
Optical Materials ◽  
Nonlinear Optical ◽  
Conformational Flexibility ◽  
Nonlinear Optical Materials ◽  
Structure Property ◽  
Bond Length Alternation ◽  
Design And Synthesis ◽  
Nlo Materials ◽  
Donor Acceptor

ABSTRACTTuning the degree of bond-length alternation in organic nonlinear optical materials is a powerful paradigm for the design of organic materials with large molecular hyperpolarizabilities (β). Several research groups have employed this paradigm in the design and synthesis of NLO materials incorporating donor-acceptor polyenes. Increased bond-length alternation in polyenes leads to decreased barriers to rotation about C=C bonds and, hence, increased conformational flexibility. Since the degree of bond-length alternation is solvent dependent, so is the degree of conformational flexibility. In an effort to probe the influence of conformational flexibility on NLO response, we synthesized a series of simple donor-acceptor polyenes that are either conformationally flexible (la, 2a, 3a) or rigid (1b, 2b, 3b). For each pair of molecules ZINDO sum-over-states calculations predict a larger value of βμ, for the conformationally flexible isomer, but EFISH measurements (CHCl3) display mixed results. Various explanations for this behavior will be considered.

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