Showing papers on "Hyperpolarizability published in 1999"
01 Jul 1999
TL;DR: In this paper, a new class of electro-optic chromophores, 2-dicyanomethylen-3-cyano-4-{2-[E -(4- N, N -di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)thien-5]- E -vinyl}-5,5-dimethyl-2-5-dihydrofuran (denoted FTC) is the prototype, has been prepared, characterized, and used to fabricate
Abstract: A new class of electro-optic chromophores, of which 2-dicyanomethylen-3-cyano-4-{2-[ E -(4- N , N -di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)thien-5]- E -vinyl}-5,5-dimethyl-2,5-dihydrofuran (denoted FTC) is the prototype, has been prepared, characterized, and used to fabricate electro-optic devices. The molecular hyperpolarizability and thermal stability of these chromophore molecules are exceptional. Strong intermolecular electrostatic interactions inhibit the efficient poling of these molecules. A statistical mechanical theoretical treatment is used to quantitatively predict the competition of poling, intermolecular electrostatic interactions, and thermal effects in defining achievable acentric order and hence macroscopic optical nonlinearity. Theory is used to predict the optimum chromophore structure and material composition (chromophore loading in a polymer matrix) for maximum electro-optic activity and minimum optical loss. Problems associated with lattice hardening to lock-in poling-induced order are discussed briefly.
249 citations
TL;DR: The first third-order nonlinear optical (NLO) measurements of an organometallic dendrimer have been obtained using the Z-scan technique at a wavelength of 800 nm.
149 citations
TL;DR: In this article, the synthesis and the NLO activities of dipolar mono-and dinuclear sandwich-like complexes are reviewed and the most important class of nonlinear optical (NLO) compounds providing second harmonic generation (SHG) comprises of electron donating and accepting groups which are electronically coupled.
140 citations
TL;DR: In this paper, a third-order non-linear THz pump-optical probe measurement of liquid dynamics is reported, which measures the correlations between the hyperpolarizability and dipole moment fluctuations at equilibrium.
114 citations
TL;DR: In this article, the static second dipole hyperpolarizability γαβγδ of trans-butadiene has been investigated in terms of the Hartree-Fock limit of the mean of the second dipoles.
Abstract: Finite-field many-body perturbation theory and coupled cluster calculations are reported for the static second dipole hyperpolarizability γαβγδ of trans-butadiene. A very large basis set of [9s6p4d1f/6s3p1d] size (336 contracted Gaussian-type functions) should lead to self-consistent field (SCF) values of near-Hartree–Fock quality. We report γxxxx=6.19, γxxxz=−0.44, γxxyy=3.42, γzzxx=2.07, γxyyz=−0.50, γxzzz=1.73, γyyyy=14.72, γyyzz=8.46, γzzzz=24.10 and γ=14.58 for 10−3×γαβγδ/e4a04Eh−3 at the experimental geometry (molecule on the xz plane with z as the main axis). γ=(14.6±0.4)×103e4a04Eh−3 should be a very reliable estimate of the Hartree–Fock limit of the mean hyperpolarizability. Keeping all other molecular geometry parameters constant, we find that near the Hartree–Fock limit the mean hyperpolarizability varies with the C=C bond length as 10−3×γ(RC=C)/e4a04Eh−3=14.93+31.78ΔR+30.88ΔR2−2.96ΔR3 and with the C–C bond length as 10−3×γ(RC–C)/e4a04Eh−3=14.93−7.20ΔR+3.04ΔR2, where ΔR/a0 is the displaceme...
110 citations
TL;DR: Using an iterative sequence of Wittig olefination, reduction, oxidation, and condensation of an active methylene group to carbonyl, it was possible to prepare a series of organometallic push-pull molecules as mentioned in this paper.
109 citations
TL;DR: In this article, the third-order optical nonlinearity of metal(dmit)2 was investigated with femtosecond optical Kerr effect at 830 nm wavelength, and the nonresonant second-order hyperpolarizability for the didodecyldimethylammonium-Au(2C12−Au) molecule was estimated to be as large as 2.2×10−32
Abstract: The third-order optical nonlinearity of metal(dmit)2 was investigated with femtosecond optical Kerr effect at 830 nm wavelength. The nonresonant second-order hyperpolarizability for the didodecyldimethylammonium–Au(dmit)2 (2C12–Au) molecule was estimated to be as large as 2.2×10−32 esu.
104 citations
TL;DR: In this paper, the NLO donor-acceptor (D-A) chromophores containing a fused terthiophene (DTT) as electron relay were synthesized to evaluate the relay's role in the solvatochromism as well as in the molecular nonlinearity, µβ(0).
Abstract: Nonlinear optical (NLO) donor-acceptor (D-A) chromophores containing a fused terthiophene, namely dithienothiophene (DTT) as electron relay, and various strength acceptors were synthesized to evaluate the relay's role in the solvatochromism as well as in the molecular nonlinearity, µβ(0). Their solvatochromic behavior, which is dependent on acceptor strength, is correlated to their µβ(0). The static quadratic hyperpolarizability, β(0), of DTT-containing chromophores was determined by EFISH measurements. From the comparison of µβ(0) values of D-A chromophores based on oligothiophenes, it was assessed that DTT as relay is significantly more efficient compared to bithiophene (the same number of conjugated double bonds) and terthiophene. An additional merit of DTT is that chromophores containing DTT have a noticeably high thermal stability.
103 citations
TL;DR: In this paper, the wavelength-dependent hyperpolarizability tensor has been modeled with a simple three-state, two-level dipolar model, and reasonable qualitative agreement between experimental results and a simple 3-state and 2-level model is obtained.
Abstract: Polarized hyper-Rayleigh scattering (HRS) has been used to interrogate a putative octupolar “super” chromophore Ru(trans-4,4‘-diethylaminostyryl-2,2‘-bipyridine)32+. While the hyperpolarizability (β) is impressive, it is apparent from polarized HRS measurements that the symmetry of the excited state, and thus the hyperpolarizability tensor, is best described as dipolar in nature. Electroabsorption (electronic Stark effect) experiments support these findings, implying that changes in dipole moment (Δμ) accompany optical excitation. The measured |Δμ| contributions from both metal-to-ligand charge transfer and intraligand transitions have been used to model the wavelength-dependent hyperpolarizability; reasonable qualitative agreement between experimental results and a simple three-state, two-level dipolar model is obtained.
103 citations
TL;DR: In this article, the tropylium ylide 12-C7H6+-CB11H11- is made in 54% yield by reaction of C7H7+ with CB11H12-.
Abstract: Salts of 12-alkyl and 12-phenyl derivatives of the CB11H12- anion are prepared in 50−60% yields from the 12-iodo-CB11H11- anion by Pd-catalyzed cross-coupling with Grignard reagents. The tropylium ylide 12-C7H6+-CB11H11- is made in 54% yield by reaction of C7H7+ with CB11H12-. Its ground-state dipole moment is 11.25 ± 0.1 D and its first hyperpolarizability is β = 236 × 10-30 esu at 1064 nm, as determined by hyper-Rayleigh scattering measurement. This value is ten times that of p-nitroaniline and is surprisingly large considering that the compound is colorless.
99 citations
IBM1
TL;DR: In this article, the frequency-dependent interaction induced polarizabilities and second hyperpolarizabilities were calculated for He2 at the coupled cluster singles and doubles and full configuration interaction levels.
Abstract: The frequency-dependent interaction induced polarizabilities and second hyperpolarizabilities are calculated for He2 at the coupled cluster singles and doubles and full configuration interaction levels and for Ar2 at the coupled cluster singles and doubles level. The frequency-dependence is approximated by a power series to second-order in the frequency arguments using Cauchy moments and hyperpolarizability dispersion coefficients. Using large correlation consistent basis sets, results close to the basis set limit are obtained. The computed curves for the interaction induced (hyper-) polarizabilities are tabulated for a range of internuclear distances. The data are employed in a companion paper to make for the first time a direct comparison between the experimentally determined pressure dependence of an ESHG hyperpolarizability and ab initio calculated hyperpolarizability second virial coefficients.
TL;DR: The first hyperpolarizability values (β) measured by hyper-Rayleigh scattering (HRS) with fluorescence suppression were (189 ± 30) × 10−30 esu at 1300 nm as discussed by the authors.
TL;DR: In this article, a series of asymmetric salicylaldiminato Schiff base ligands 1, 4 and 9 with different substituents were chosen as models for a theoretical investigation.
TL;DR: Theoretical descriptions of the molecular polarizability and second hyperpolarizability (α and γ) of the linear quadrupolar molecule are presented in this paper.
Abstract: Theoretical descriptions of the molecular polarizability and second hyperpolarizability (α and γ) of the linear quadrupolar molecule are presented. By using a valence-bond and two charge-transfer states, three eigenfunctions of a quadrupolar molecule are obtained as linear combinations of these basis states. The analytic expressions for α and γ are obtained, and the physical picture on the nonlinear optical (NLO) response of the quadrupolar molecule is presented. By introducing the bond-length-alternation coordinates into the model Hamiltonian, the relationships of various vibrational characteristics, such as IR, Raman, and hyper-Raman intensities and vibrational frequencies, with respect to the molecular structure are established. The vibrational second hyperpolarizability is also compared with the electronic one, and the two quantities show similar trends as the charge-transfer character changes. A number of distinctive features are discussed by comparing the results with those of the linear push−pull p...
TL;DR: In this article, a model was presented which allows to obtain a linear relationship between infrared and Raman intensity parameters of the strongest vibrational bands of push-pull conjugated molecules and clarify the origin of the exceptionally large values of the vibrational first hyperpolarizability shown by these molecules.
TL;DR: In this paper, the authors show how sizable medium effects on molecular electrical response of polymeric solids can arise; they also show that classical electrostatics accurately reproduces a full quantum treatment; and for a large bundle of hexatriene molecules taken as a model of polyacetylene, the medium effect will lead to as much as a 95% reduction in the second hyperpolarizability and a 50% reduction of the polarizability.
TL;DR: Poly(triacetylenes) are rodlike molecules with electrons delocalized over a one-dimensional path that exhibit a power-law dependence of the second-order hyperpolarizability gamma on the monomer unit n for short molecules and a smooth saturation toward a linear increase in longer molecules.
Abstract: Poly(triacetylenes) are rodlike molecules with electrons delocalized over a one-dimensional path. We show that they exhibit a power-law dependence of the second-order hyperpolarizability ? on the monomer unit n for short molecules and a smooth saturation toward a linear increase in longer molecules. The power law of ??na with a?2.5 from dengenerate four-wave mixing and third-harmonic generation measurements is in good agreement with quantum-chemical calculations. The critical conjugation length for saturation in the three cases is shown to be approximately 60 carbon–carbon bonds, which indicates the upper boundary for the electron delocalization in such a one-dimensional molecular wire.
TL;DR: In this paper, the second order optical nonlinearity γR (second hyperpolarizability or nonlinear refractive index) was measured for a series of sulfur-rich molecules: sulfur (S8), carbon−sulfur compounds, and metal thiolate clusters.
Abstract: The molecular third-order optical nonlinearity γR (second hyperpolarizability or nonlinear refractive index) was measured for a series of sulfur-rich molecules: sulfur (S8), carbon−sulfur compounds, and metal thiolate clusters. Z-scan techniques (pulse width 27 ps, wavelength 527 nm) were used to measure these properties in solution by comparing the solution to the pure solvent. Our approach is an efficient way to evaluate a number of different compounds and to quickly direct synthetic strategies for improved nonlinear and linear optical properties. The optical nonlinearities were evaluated in terms of figures of merit, |W|/I0 and [T]-1, where |W|/I0 is the ratio of nonlinear refraction to linear absorption and [T]-1 is the ratio of nonlinear refraction to nonlinear absorption. Among the carbon−sulfur compounds, C6S8O2 had the largest figures of merit: |W|/I0 = 4.3 × 10-13 m2 W-1 and [T]-1 > 5. The metal thiolate cluster with the largest second hyperpolarizability was [Zn10S4(SPh)16]4- (γR = −7.8 × 10-5...
TL;DR: In this paper, the effects of axial ligands in Sn(IV)-substituted 5,10,15,20-tetrakis [4-(carboethoxymethyleneoxy)phenyl]porphyrin and divalent transition metal substitution were studied using the Z-scan technique.
Abstract: The effects of axial ligands in Sn(IV)-substituted 5,10,15,20-tetrakis [4-(carboethoxymethyleneoxy)phenyl]porphyrin and divalent transition metal substitution in 5,10,15,20-tetraphenylporphyrin on the second molecular hyperpolarizability (γ) at 802 nm were studied using the Z-scan technique. A significant increase in γ for divalent metal ions is observed with decreasing d-shell occupancy. In the case of the tetravalent metal-substituted porphyrin a dramatic enhancement of γ is seen when a strongly electronegative axial ligand such as I2 is attached to the metal ion. A plausible explanation for the observed trend of γ has been sought in terms of metal-ligand interaction.
TL;DR: In this article, a push-pull thiazole-containing nonlinear optical chromophores with dicyanovinyl acceptors, along with their thiophene analogs, have been synthesized and characterized.
Abstract: Push-pull thiazole-containing nonlinear optical chromophores with dicyanovinyl and tricyanovinyl acceptors, along with their thiophene analogs, have been synthesized and characterized. The onset temperatures of thermal decomposition of these chromophores determined by DSC are above 240 °C. The redox properties of the chromophores were studied by cyclic voltammetry and the results reveal the electron-deficient (thiazole) and electron-excessive (thiophene) nature of the heterocycles. Experimental measurements of second-order nonlinear optical response (µ·β) indicate that the combination of either a thiazole or thiophene conjugating unit and a tricyanovinyl acceptor results in a nonlinear optical chromophore exhibiting substantial molecular hyperpolarizability (µ·βca. 7000×10
–48
cm
6
at 1907 nm).
TL;DR: In this paper, a theoretical analysis of the first-order hyperpolarizability properties (β) of polyenic molecules of octupolar C3h symmetry (polyenoctupoles), based on CNDO/S calculations, and interpreted in the frame of a tensorial formalism, is presented.
TL;DR: In this article, the dielectric, refractivity, Kerr, and hyperpolarizability second virial coefficients for the helium and argon gases are evaluated for a wide range of temperatures using a semiclassical approach and the high quality frequency-dependent interaction induced electric polarizabilities.
Abstract: The dielectric, refractivity, Kerr, and hyperpolarizability second virial coefficients for the helium and argon gases are evaluated for a wide range of temperatures using a semiclassical approach and the high quality frequency-dependent interaction induced electric polarizabilities and second hyperpolarizabilities of the previous paper. For helium and argon we obtain satisfactory agreement with most of the experimental data for the dielectric and the refractivity second virial coefficients. Our results confirm that the helium gas second Kerr virial coefficient is very small at temperatures beyond 70 K. For argon we obtain a very good agreement with a recent experimental determination at 632.8 nm, whereas we suggest that previous experimental results for 458 nm might be inaccurate. The ESHG results indicate a possible disagreement between a recent experimental determination and the semiclassical ansatz for the second hyperpolarizability virial coefficients.
TL;DR: In this article, the frequency-dependent interaction induced polarizability and second hyperpolarizability of the argon dimer were computed for a range of internuclear distances employing the coupled cluster singles and doubles response approach.
Abstract: The frequency-dependent interaction induced polarizability and second hyperpolarizability of the argon dimer are computed for a range of internuclear distances employing the coupled cluster singles and doubles response approach. The frequency dependence of the interaction-induced properties is treated through second order in the frequency arguments using expansions in Cauchy moments and hyperpolarizability dispersion coefficients. The dielectric, the refractivity, the Kerr and the hyperpolarizability second virial coefficients are computed for a range of temperatures employing a recent accurate ab initio potential for the ground state of the argon dimer. For most of the computed virial coefficients good agreement is obtained between the present ab initio results and the available experimental data.
TL;DR: In this paper, the static electronic longitudinal polarizability (α) and second hyperpolarizability of polyacetylene chains have been computed at different levels of approximation by varying the bond length alternation (BLA) along the conjugated backbone.
Abstract: The static electronic longitudinal polarizability (α) and second hyperpolarizability (γ) of all-trans planar polyacetylene chains have been computed at different levels of approximation by varying the bond length alternation (BLA) along the conjugated backbone. Although the restricted Hartree–Fock (RHF) and second-order Moller–Plesset (MP2) approaches exhibit the expected behavior, i.e., the smaller the BLA, the larger the γ, the density functional schemes based on the SVWN and B3LYP exchange correlation functionals behave in a totally different way: when BLA increases, γ first increases, attains a maximum, and then decreases. Moreover, the RHF approach is found to overestimate by a factor of 2–3 the BLA dependence of α with respect to the MP2 procedure. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 75: 441–447, 1999
TL;DR: In this paper, the first hyperpolarizability data obtained by using the 1907 nm excitation are consistent with electric field induced second harmonic generation data obtained with using the same wavelength.
Abstract: Hyper-Rayleigh scattering (HRS) has been carried out for new azulenic donor–acceptor chromophores using near-infrared laser excitation at wavelengths of 1064 and 1907 nm. Hyperpolarizabilities obtained with the 1064 nm incident excitation are large compared with those obtained using the 1907 nm excitation, due to the effects of two-photon resonance enhancements in the former case. The HRS experiment using the 1907 nm excitation, while challenging to carry it out, gives the hyperpolarizability value closer to the intrinsic molecular hyperpolarizability. The popular two-level model that is used to predict the first hyperpolarizability of donor–acceptor charge transfer chromophores is employed to compare the measurements made on the same chromophores with 1064 and 1907 nm excitations. The model is found not to be able to correlate the results obtained at the two wavelengths. The first hyperpolarizability data obtained by using the 1907 nm excitation are consistent with electric field induced second harmonic generation data obtained by using the same wavelength.
TL;DR: In this article, the Hartree-Fock estimate for the static ZPVA correction to γ is found to be 10% of the corresponding electronic contribution, and the dynamic pure vibrational hyperpolarizability, despite being significant for the optical Kerr effect and intensity-dependent refractive index, reduces in magnitude for second and third harmonic generation.
TL;DR: Carbonylrhenium bromide complexes with conjugated pyridines fac-Br(OC)3ReL2 (L = FcCH:CH-p-C5H4N (Fc = ferrocenyl), Fc CH:CHC(Me):CHCH: CHCH: C(Me)CH:Ch-p -C4N, 1,1'Fc(CH:C-4N)2 p-Me2NC6H4CH:
Abstract: Carbonylrhenium bromide complexes with conjugated pyridines fac-Br(OC)3ReL2 (L = FcCH:CH-p-C5H4N (Fc = ferrocenyl), FcCH:CHC(Me):CHCH:CHCH:C(Me)CH:CH-p-C5H4N, 1,1'Fc(CH:CH-p-C5H4N)2 p-Me2NC6H4CH:CHCH:CH-p-C5H4N (I), and p-Me2NC6H4CH:CHC(Me):CHCH:CHCH:C(Me)CH:CH-p-C5H4N) and cis-Br(OC)4ReL (L = FcCH:CH-p-C5H4N (II) and p-Me2NC6H4CH:CHCH:CH-p-C5H4N) were synthesized. The structures of I (monoclinic, C2/c, a = 18.3826(1), b = 15.1048(1), c = 28.5866(1) .ANG., b = 92.848(1) Deg, V = 7927.71(7) .ANG.3, Z = 8, rc = 1.636 g/cm3, m(MoKa) = 4.317 mm-1, F(000) = 3848, 7804 independent reflections, 480 refined parameters, R1 = 0.0726, wR2 = 0.1723) and II (rhombohedral, R.hivin.3, a = 30.357(4), c = 12.398(2) .ANG., V = 9895(2) .ANG.3, Z = 18, rc = 2.016 g/cm3, m(MoKa) = 8.003 mm-1, F(000) = 5688, 2930 independent reflections, 262 refined parameters, R1 = 0.0578, wR2 = 0.1048) were detd. by x-ray diffraction anal. Compd. I exhibits a remarkable quadratic hyperpolarizability. [on SciFinder (R)]
TL;DR: In this article, a new Stark-type experimental technique known as electroabsorption spectroscopy has been developed in S. G. Boxer's laboratories which offers the ability to measure the responses of isotropic solvated molecules to an applied electric field.
Abstract: A new Stark-type experimental technique known as electroabsorption spectroscopy has been developed in S. G. Boxer's laboratories which offers the ability to measure the responses of isotropic solvated molecules to an applied electric field. It is applicable to a wide range of molecules and environments. We present benchmark ab initio and density-functional calculations employing 14 methods and double-ζ to penta-ζ augmented basis sets for the vibrational frequencies, dipole moment, polarizability, hyperpolarizability profiles, Stark shift, and other electroabsorption properties of two important (gas-phase) molecules, CO and CN-, for which a range of high-precision experimental data is available. The results show excellent agreement with these data, verify the earlier conclusion that the transition-moment polarizability rather than the polarizability change dominates the first-derivative response in the electroabsorption spectroscopy of these systems, and convergence with respect to the treatment of electro...
TL;DR: In this article, a chiral cyanine dye, 4'-[methoxymethyl)pyrrolidinyl]-1-methylstilbazolium iodide (MPMS+I-) is reported.
Abstract: A new chiral cyanine dye, 4‘-[2-(methoxymethyl)pyrrolidinyl]-1-methylstilbazolium iodide (MPMS+I-) is reported. It crystallizes in the monoclinic P21 space group. a = 16.559(2) A, b = 6.263(1) A, c = 24.477(3) A, β = 109.20(1)°, Z = 2. The hyperpolarizability of MPMS+I- is compared versus that of 4‘-dimethylamino-1-methylstilbazolium iodide (DAMS+I-). MPMS+I- is phase matchable and exhibits an efficiency up to 80 times that of urea in second-harmonic generation (SHG). Both compounds (C+I-) react with tetracyanoquinodimethane (TCNQ), and the resulting C+(TCNQ2)- exhibit conductivities in the range 10-3−10-2 S cm-1. The possibility of combining conductivity and optical nonlinearities is discussed.