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Two novel nonlinear optical (NLO) chromophores JC-T-TCF and JC-F-TCF utilizing tetramethyljulolidine-based coumarin and tricyanofuran(TCF) as the electron donor and acceptor, respectively, were designed and synthesized. The two chromophores were linked with different π conjugated electron bridge (thiophene group and furan group), which provide the opportunity to study the structure–property relationship of coumarin-based chromophores. Both the novel obtained chromophores exhibited reasonable stability and solvatochromic effect. The theoretical calculation results indicated that both chromophores possess microscopic hyperpolarizability (β) in excess of 320 × 10−30esu, and the chromophore JC-T-TCF utilizing thiophene group as the electron bridge exhibited obviously larger β value (456.8 × 10−30esu). The larger β value, combination with the larger µ value, endowed JC-T-TCF with larger electro-optic activity of 70 pm V−1 at the wavelength of 1310 nm in the guest–host films of chromophores doped into PMMA, which provide the potential application opportunity in the field of optical waveguide devices. [ABSTRACT FROM AUTHOR]

Developing new organic chromophores with a large electro-optic coefficient (r33) is highly desirable for fabricating electro-optic (EO) materials. Building on the fact that the 1,1,7,7-tetramethyl julolidine fused furan ring is a good electron donor and lengthening the π-bridge of a chromophore with a five-membered heterocycle ring could lead to the improvement of r33. Here we design and synthesize two new chromophores C1 and C2 by using a 1,1,7,7-tetramethyl julolidine fused furan ring as the electron donor and 2-(3-cyano-4,5,5-trimethyl-5H-furan-2-ylidene)-malonitrile (TCF) as the acceptor, but with two different π-bridges (furan-vinylene and thiophene-vinylene accordingly). When doping C1 or C2 into PMMA with a loading density of 20 wt%, the poled films containing C1 or C2 exhibited an r33 value of 75 pm V−1 and 94 pm V−1, respectively. When compared with chromophore C3 (an ene unit as the π-bridge, r33 = 52 pm V−1), an enhanced r33 of C1 and C2 was achieved due to the introduction of a heterocycle ring into the π-bridge. This work uncovers the influence of the heterocycle ring on the julolidine fused furan based chromophore's physical and chemical properties and demonstrates that the new chromophores are a promising candidate for EO material application. [ABSTRACT FROM AUTHOR]

Two principally novel chromophores A, B based on fluorene electron donor were synthesized and explored by 1H NMR, 13C NMR, and MS spectra. The delocalized energy levels have been estimated by UV–Vis absorption spectra. The principal innovation consists in modification by addition of amino group. The titled materials have demonstrated a high solubility in common organic solvents, good compatibility with polymers. The maximally achieved electro-optic efficiency of the poled film possessing 25 wt% of A doped in PMMA (25 wt% A/PMMA) achieved a value of 18 pm/V at wavelength 1310 nm, and 25 wt% B/PMMA possessed an electrooptical coefficient equal to 43 pm/V. This one open a perspective of their direct application in optoelectronic telecommunication devices for laser light modulation. [ABSTRACT FROM AUTHOR]

Buchwald-Hartwig amination of aryl halides with solvent-free condition was used for the preparation of electron donors with high density of electron cloud. Organic second order nonlinear optical chromophore ZML-c based on this electron donor was designed and synthesized. And chromophore ZML-ref without modified groups was also prepared as the contrast. Their delocalized energy levels were estimated by UV–Vis. spectra. Their thermal properties were studied by thermogravimetric analysis (TGA). Obviously, chromophore ZML-c showed lower delocalized energy levels and lower thermal decomposition temperature (just about 160 °C). The poled films showed the largest electro-optic (EO) coefficients of 23.5 pm/V and 10.6 pm/V respectively for chromophore ZML-c and ZML-ref. These results indicate that effective modification in indole ring may be a promising way to drastically change the electro-optical features of the titled compounds and show a direction of designing new electron donor in the field of nonlinear optical materials. [ABSTRACT FROM AUTHOR]

Organic electro-optic (EO) materials have been widely explored and used in the fabrication of microwave photonic devices. Their principal advantages are the follows: lower half-wave voltage, wider bandwidth, lower cost and more convenience of integration. Organic second order nonlinear optical (NLO) chromophores, as the core of the organic EO devices, define the key technological parameters: EO efficiency, long term stability, solubility and optical losses. In the present review article, the use of D–π–A chromophore molecules with polycyclic electron donors based on julolidinyl structure is reported and discussed. Significant improvement of electron donating ability and appropriate isolated effect are shown. Future perspectives of the application of such kind of NLO chromophores are considered. [ABSTRACT FROM AUTHOR]

Novel nonlinear optical (NLO) chromophore based on 6-(pyrrolidin-1-yl)-1H-indole as the electron donor group was designed and synthesized. The molecular structure of this chromophore was characterized by 1 H NMR spectra, 13 C NMR spectra, and MS spectra. The delocalized energy level was estimated by UV–Vis. spectra. The thermal property was studied by thermogravimetric analysis (TGA). The poled films containing chromophores ZML-1 with a loading density of 10 wt% in amorphous polycarbonate (APC) afford an average electro-optic (EO) coefficient ( r 33 ) of 19 pm/V at 1310 nm. Compared to the reported aniline-based chromophore ( r 33 = 12 pm/V) analogues, chromophore ZML-1 exhibits enhanced electro-optical activity. [ABSTRACT FROM AUTHOR]

Novel nonlinear optical (NLO) chromophore using benzo[b]furan moiety and trifluoromethyl-substituted tricyanofuran as the electron donor and acceptor respectively was designed and prepared. The structure of the novel chromophore was determined by NMR spectra, and the photophysical properties were studied via UV-vis spectra. The thermal decomposition temperature (T d)value of the obtained NLO chromophore reached to 212 °C, which endow the chromophore with good thermal stability during the materials processing. The nonlinearity of the chromophore was evaluated through theoretical calculation and electro-optic (EO) activity test, and the highest EO coefficient (r 33) was determined to 28 pm/V at the loading density of 25 wt% in polymethyl methacrylate. • Novel benzofuran-based nonlinear optical chromophore was designed and synthesized. • The acceptor was unexpected linked to the β -position of furan in the chromophore. • The present chromophore exhibited go0d thermal stability (T d reached to 212 °C). • The maximum EO coefficient of the reported chromophore reached to 28 p.m./V. [ABSTRACT FROM AUTHOR]

Highlights • A new chromophore was investigated. • Phenothiazine with rich electron sulfur and nitrogen heteroatoms was introduced. • The new structure chromophore showed good nonlinear optical properties. Abstract A novel chromophore based on the phenoxazine and tricyanofuran acceptor linked together via thiophene as the bridges have been synthesized by the conventional technique and systematically investigated. Structure analysis and photophysical properties were carried out to investigate the new structure chromophore. Density functional theory was used to calculate the hyperpolarizability (β) and the result shows that chromophore A showed a lower energy gap. In addition, chromophore A displayed good thermal stability with the onset decomposition temperature over 240 °C. These results showed that chromophore A, which had good thermal stability and nonlinear optical properties was a promising candidate for practical use. [ABSTRACT FROM AUTHOR]

A novel chromophore based on N -(4-dibutylaminophenyl)tetrahydroquinolinyl donor group was synthesized to compare with traditional chromophores based on either diethylaminophenyl or triarylaminophenyl donor groups. Cyclic voltammetry measurements showed that the new chromophore had a much smaller energy gap than the structurally related chromophores. Density functional theory calculations suggested that the molecular quadratic hyperpolarizability (μβ) value of tetrahydroquinolinyl chromophore is 65% and 110% larger than that of either the diethylaminophenyl or triarylaminophenyl chromophores, respectively. The doped film containing the tetrahydroquinolinyl chromophore showed an r 33 value of 126 pm/V at the concentration of 25 wt% which is much higher than the electro-optic activity of the diethylaminophenyl derived chromophore (39 pm/V) and six times higher than that of the traditional triarylaminophenyl chromophore (19 pm/V). The tetrahydroquinolinyl chromophore possesses much higher thermal stability (with its onset decomposition temperature above 280 °C) than those of commonly used alkyl chromophores. [ABSTRACT FROM AUTHOR]

Two novel chromophores based on the phenoxazine (chromophore L1) or phenothiazine (chromophore L2) donor, and tricyanofuran acceptors linked together via thiophene as the bridges have been synthesized and systematically investigated. Cyclic voltammetry measurements showed that chromophore L1 had smaller energy gap than chromophore L2 due to the stronger electron-donating ability. Moreover, Density functional theory calculations suggested that the β value of chromophore L1 is 17% larger than that of chromophore L2. The doped film containing the chromophore L1 showed an r 33 value of 49 pm/V at the concentration of 25 wt% which is two times higher than the EO activity of the chromophore L2 (23 pm/V) and the traditional aryl chromophore (10–20 pm/V). High r 33 value, high thermal stability (onset decomposition temperatures higher than 220 °C) suggests the potential use of the new chromophore in nonlinear optical materials. [ABSTRACT FROM AUTHOR]