Increase and saturation of the third order hyperpolarizabilities in homologous series of symmetric cyanines

Werncke, W.; Pfeiffer, M.; Johr, T.; Lau, A.; Grahn, Walter; Johannes, H.‐H.; Dähne, Lars

doi:10.1016/s0301-0104(97)00029-3

Cited by 21 publications

(20 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar effect was noted by Wernke et al when comparing dimethylamino-and benzothiazole-terminated polymethines: for a given chain length between the two nitrogen atoms, a member of the latter class has twelve additional p-electrons relative to its analogue in the former class, but the red-shift observed is similar to what would be obtained on adding one vinylene group to the bridge. [10] This suggests that the terminal groups provide less contribution to the frontier molecular orbitals than the polymethine bridge of the dye, a feature we discuss in more detail below.…”

Section: Linear Optical Properties Of 1-6mentioning

confidence: 99%

“…[7,8] The third-order polarizabilities of polymethines are strongly dependent on the length of the polymethine chain. For example, g has been shown to increase with N 8 AE 2 , where N is the number of p-electrons in the polymethine chain, for cyanine dyes of type I (Figure 1) [9] and, at least for moderate chain lengths, for dyes of type II, [10] with larger values of g being observed for a given N in the latter series. However, both theoretical [11][12][13][14] and experimental [15][16][17][18] work suggests that polymethines undergo symmetry breaking somewhat analogous to a Peierls distortion at long chain lengths, or with particular end Six anionic pentamethine dyes with different 2,2-difluoro-4-aryl-1,3,2(2 H)-dioxaborin-6-yl termini were synthesized and isolated as tetra-n-octylammonium salts with a variety of aryl groups appended to increase conjugation beyond the dioxaborine termini.…”

Section: Introductionmentioning

confidence: 98%

“…Indeed, incipient symmetry breaking may contribute to the saturation of g with chain length observed in the II and III series of polymethine dyes ( Figure 1). [10,19,20] Recently we have found that the bis(dioxaborine)-terminated nonamethine IV (Figure 1) appears to be less affected by symmetry breaking than other dyes with similar absorption maxima, exhibits very large, predominantly real, values of g in the telecommunications bands of the near-IR (real and imaginary parts are À5. 7 10 À32 and 7.9 10 À33 esu, respectively, at 1.3 mm), and that thin films can be fabricated that exhibit correspondingly large c (3) (real and imaginary parts are À3.6 10 À10 and 3.8 10 À11 esu, respectively, at 1.3 mm).…”

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes

Matichak¹,

Hales²,

Ohira³

et al. 2010

ChemPhysChem

View full text Add to dashboard Cite

Six anionic pentamethine dyes with different 2,2-difluoro-4-aryl-1,3,2(2 H)-dioxaborin-6-yl termini were synthesized and isolated as tetra-n-octylammonium salts with a variety of aryl groups appended to increase conjugation beyond the dioxaborine termini. The increased conjugation was expected to decrease the energy of the lowest-lying excited state, and increase the transition dipole moment linking this state to the ground state, which would be anticipated to result in an increase in the real part of the third-order polarizability, Re(gamma). UV/Vis-NIR absorption spectroscopy indicates that the absorption maxima in DMSO vary from 691 to 761 nm, with the longest wavelength transitions observed for a derivative where the aryl group is 4-nitrophenyl. Closed-aperture Z-scan measurements at 1.3 microm in DMSO indicate that Re(gamma) varies from -2.9x10(-33) to -5.4x10(-33) esu in these systems. The largest magnitude of Re(gamma) was observed for a dye with E-4-styrylphenyl aryl groups. This result can be rationalized using a two-state expression which relates Re(gamma) to the energy and transition dipole moment of the transition from the ground state to the lowest-lying excited state. A nonamethine analogue of this compound was also synthesized and exhibits a slightly larger Re(gamma) with respect to a previously reported bis(dioxaborine)-terminated nonamethine. The extension of conjugation beyond the dioxaborine termini seems to result in an overall increase in Re(gamma). However, the effects are smaller than those found by increasing conjugation in the polymethine bridge due to reduced participation of terminal groups in the HOMO.

show abstract

Section: Linear Optical Properties Of 1-6mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes

Matichak¹,

Hales²,

Ohira³

et al. 2010

ChemPhysChem

View full text Add to dashboard Cite

show abstract

“…Chemical structures of the polymethines studied in this work. 4 However, much experimental evidence [18][19][20][21][22][23][24][25][26][27] underlines that when the dye is sufficiently long, polymethine geometries undergo a symmetry-breaking transition such that the excess charge becomes localized primarily on one end of the molecule. The absorption peaks then substantially broaden on the high-energy side or shift altogether to higher energy.…”

Section: Introductionmentioning

confidence: 99%

“…The absorption peaks then substantially broaden on the high-energy side or shift altogether to higher energy. 18,22,[28][29][30] This change is accompanied by a saturation or decrease in the magnitude of Re(γ) 23 and the appearance of a non-zero β. 27 These modifications in the optical and NLO properties are consistent with an increase in BLA.…”

Section: Introductionmentioning

confidence: 99%

Benchmarking Density Functional Theory Approaches for the Description of Symmetry Breaking in Long Polymethine Dyes

et al. 2016

View full text Add to dashboard Cite

Long polymethines are well-known experimentally to symmetry-break, which dramatically modifies their linear and nonlinear optical properties. Computational modeling could be very useful to provide insight into the symmetry-breaking process, which is not readily available experimentally; however, accurately predicting the crossover point from symmetric to symmetry-broken structures has proven challenging. Here, we benchmark the accuracy of several DFT approaches relative to CCSD(T) geometries. In particular, we compare analogous hybrid and long-range corrected (LRC) functionals to clearly show the influence of the functional exchange term. Although both hybrid and LRC functionals can be tuned to reproduce the CCSD(T) geometries, the LRC functionals are better performing at reproducing the geometry evolution with chain length and provide a finite upper limit for the gas-phase crossover point; these methods also provide good agreement with the experimental crossover points for more complex polymethines in polar solvents. Using an approach based on LRC functionals, a reduction in the crossover length is found with increasing medium dielectric constant, which is related to localization of the excess charge on the end groups. Symmetry-breaking is associated with the appearance of an imaginary frequency of b 2 symmetry involving a large change in the degree of bond-length alternation. Examination of the IR spectra show that short, isolated streptocyanines have a mode at ~1200 cm -1 involving a large change in bond-length alternation; as the polymethine length or the medium dielectric increases, the frequency of this mode decreases before becoming imaginary at the crossover point.

show abstract

Bis(1,3-dithiole) Polymethine Dyes for Third-Order Nonlinear Optics – Synthesis, Electronic Structure, Nonlinear Optical Properties, and Structure-Property Relations

Simonsen¹,

Geisler

Petersen

et al. 1998

Eur. J. Org. Chem.

View full text Add to dashboard Cite

The synthesis of a series of new sulfur‐containing polymethine dyes is reported. The linear optical properties of these bis(1,3‐dithiole) (mono‐, tri‐, penta‐, and hepta‐)methine dyes show intense and narrow optical absorptions typical of cyanine dyes. The absorption maximum is increasingly red‐shifted from 489 nm for the monomethine dye to 911 nm for the heptamethine compound. Based on third‐harmonic generation measurements at fundamental wavelength between 1064 nm and 1907 nm, γ values were evaluated to lie in the range between 1·10−33 e.s.u. and 14·10−33 e.s.u. showing that the nonlinear response of the bis(1,3‐dithiole) polymethine dyes compare well with other organic π‐electron systems of similar size. Comparisons of the experimental values of γ to calculated static values obtained by ab initio and semiempirical calculations (AM1, PM3) have been made as well as comparisons to dynamic values estimated from a free‐electron model. The computed dynamic values can be described by a power law; γ ≈ L5 where L denotes the length of the molecules. Our studies confirm the stabilizing effect of a carbocyclic ring in the cyanine backbone making the heptamethine dye an unusually stable and highly nonlinear polymethine chromophore possessing a strong NIR optical transition and very good transparency in the visible region.

show abstract

Increase and saturation of the third order hyperpolarizabilities in homologous series of symmetric cyanines

Cited by 21 publications

References 27 publications

Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes

Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes

Benchmarking Density Functional Theory Approaches for the Description of Symmetry Breaking in Long Polymethine Dyes

Bis(1,3-dithiole) Polymethine Dyes for Third-Order Nonlinear Optics – Synthesis, Electronic Structure, Nonlinear Optical Properties, and Structure-Property Relations

Contact Info

Product

Resources

About