Design Of New Chromophores Research Articles

Methodologies in Spectral Tuning of DSSC Chromophores through Rational Design and Chemical-Structure Engineering.

The investigation of new photosensitizers for Grätzel-type organic dye-sensitized solar cells (DSSCs) remains a topic of interest for researchers of alternative solar cell materials. Over the past 20 years, considerable and increasing research efforts have been devoted to the design and synthesis of new materials, based on “donor, π-conjugated bridge, acceptor” (D–π–A) organic dye photosensitizers. In this paper, the computational chemistry methods are outlined and the design of organic sensitizers (compounds, dyes) is discussed. With reference to recent literature reports, rational molecular design is demonstrated as an effective process to study structure–property relationships. Examples from established organic dye sensitizer structures, such as TA-St-CA, Carbz-PAHTDDT (S9), and metalloporphyrin (PZn-EDOT), are used as reference structures for an examination of this concept applied to generate systematically modified structural derivatives and hence new photosensitizers (i.e., dyes). Using computer-aided rational design (CARD), the in silico design of new chromophores targeted an improvement in spectral properties via the tuning of electronic structures by substitution of molecular fragments, as evaluated by the calculation of absorption profiles. This mini review provides important rational design strategies for engineering new organic light-absorbing compounds towards improved spectral absorption and related optoelectronic properties of chromophores for photovoltaic applications, including the dye-sensitized solar cell (DSSC).

ChemInform Abstract: The Importance of Various Anchoring Groups Attached on Porphyrins as Potential Dyes for DSSC Applications

AbstractReview: 124 refs.

Special Issue: Functional Molecules for Electronics/Optoelectronics: (Adv. Mater. 5/2012)

Advanced MaterialsVolume 24, Issue 5 p. 569-569 Cover PictureFree Access Special Issue: Functional Molecules for Electronics/Optoelectronics: (Adv. Mater. 5/2012) First published: 26 January 2012 https://doi.org/10.1002/adma.201290019AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract The front cover of this Special Issue on functional molecules for electronics/optoelectronics illustrates the “molecular toolbox” approach that has been impressively and very successfully used by Klaus Müllen and his co-workers over the years in the design of new chromophores, oligomers, den-drimers, and polymers of different dimensionality (1D, 2D, 3D). This Special Issue also celebrates Klaus Müllen's 65th Birthday. Volume24, Issue5Special Issue: Functional Molecules for Electronics/OptoelectronicsFebruary 2, 2012Pages 569-569 RelatedInformation

Synthesis of chromophores combining second harmonic generation and two photon induced fluorescence properties

The design of new chromophores presenting simultaneous SHG and TPEF properties is reported.

Molecular Engineering of Octupolar NLO Molecules and Materials Based on Bipyridyl Metal Complexes

AbstractFor Abstract see ChemInform Abstract in Full Text.

Molecular Engineering of Octupolar NLO Molecules and Materials Based on Bipyridyl Metal Complexes

Coordination compounds are of particular interest for the design of new chromophores with large nonlinear optical (NLO) susceptibilities. They offer a wide range of metals with different oxidation states and ligands, which can give rise to tunable electronic properties. Metal ions are excellent templates to build 2D and 3D octupolar NLO-phores. Their associations with functionalized bipyridyl ligands give rise to octahedral and tetrahedral metal complexes with large first-order hyperpolarizabilities. The ability to functionalize these octupoles allows their incorporation into macromolecular architectures such as polymers and metallodendrimers, We also show in this Account two approaches to induce noncentrosymmetry at the macroscopic level, either by supramolecular organization or by the all optical poling procedure.

Theoretical Design of Substituted Tetrathia‐[7]‐Helicenes with Large Second‐Order Nonlinear Optical Responses

Second-order nonlinear optical (NLO) materials have attracted a lot of interest because of foreseeable applications in optoelectronic technology. In particular, organic compounds are attractive for this purpose because of their large and fast responses combined with the flexibility of organic synthesis which hastens the design of new chromophores. The first generation of NLO organic chromophores consists of one-dimensional (1D) p-conjugated systems end-capped with donor (D) and acceptor (A) moieties. Experimental and theoretical work has shown during the last decades how to choose the D/A strengths and p segments for optimizing the second-order NLO responses. Later, two-dimensional (2D) octupolar molecules such as 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) were shown to exhibit second-order NLO responses that can be as large as those of their dipolar analogues. In addition, with these 2D structures, some of the limitations of the 1D dipolar structures were displaced, if not overcome. Indeed, 1D compounds suffer from the transparency–efficiency tradeoff, which is difficult to achieve because the desirable increase in b(the first hyperpolarizability) is accompanied by a bathochromatic shift of the electronic transitions. Moreover, their dipolar nature and the predominance of dipole–dipole intermolecular interactions favor the formation of centrosymmetric crystal arrangements which exhibit no second harmonic generation (SHG) responses. In addition, phase-matching conditions cause only a fraction of the microscopic response to be preserved at the macroscopic scale. On the other hand, octupolar compounds present an improved nonlinearity/transparency tradeoff, enable non-centrosymmetric crystal structures owing to their lack of permanent dipole moment, and present large offdiagonal b tensor components that can give rise to large macroscopic SHG responses.

Optical Limiting Characteristics of Dendrons and Dendrimers Incorporating Dithienylpolyene Moieties

AbstractOver the past decade there has been considerable progress in the design of new chromophores for potential optical limiting applications. Most of the focus has been centered on molecules that are capable of efficient excited state absorptions whose cross-sections are larger than the original π–π* excitation cross-section, usually referred to as reverse saturable absorbers (RSAs). The vast majority of chromophores having RSA characteristics depend on efficient intersystem crossing from the excited state singlet (S1) to a highly absorbing and relatively long-lived triplet state (T1). However, much less attention has been paid to alternative excited state absorptions, particularly from charge states such as polaronic radical-ions and bipolaronic diions. In this presentation, we propose that monodisperse dendrimers based on dendron coupling to core molecules such as bisphenol A are potential optical limiting materials based on photo-generation of such charge states in the dendron-attached chromophores, such as dithienylpolyenes. The design and syntheses of these dendrons and dendrimers are presented, and the absorption characteristics of the most likely charge states discussed from an optical limiting perspective.