147622-01-3

Upstream product

• 60758-38-5 2,2'-[(4-iodophenyl)azanediyl]di(ethan-1-ol) 
• 108-24-7 acetic anhydride 
• 120-07-0 2,2'-(phenylimino)bis[ethanol] 
• 19249-34-4 bis(2-acetoxyethyl)aniline 

Downstream Products

• 1223510-97-1 C₁₇H₂₁NO₅ 
• 1223510-90-4 4-[N,N-bis(2-acetoxyethyl)amino]phenylacetylene 

Relevant academic research and scientific papers

Photophysical insights on the influence of excited states reorganization processes on the visible and near infra-red luminescence of two-photon quadrupolar chromophores

We synthesized three different families of quadrupolar dyes, differing by the nature of their aromatic central cores (phenyl, fluorenyl, anthracenyl), in which we systematically varied the length of the π-conjugated backbone and the nature of the central bridge. We compared their linear and non-linear spectroscopic and photophysical features. We showed that the introduction of a diyne bridge is efficient in consistently increasing the Stokes shifts in these fluorophores, especially in high polarity solvents. By a combined theoretical and spectroscopic study we show that this feature is favoured by distortion of their π-conjugated skeleton at the electronic ground state. Unfortunately, this distortion process is generally detrimental to their fluorescence quantum yields. However, in the course of this study, we identify a particularly promising dye, that combines a large two-photon absorption (650 GM@760 nm) while keeping efficient emission (?f = 0.3) in the far-red/NIR (ca 700 nm) in polar solvent (DMSO).

Poling and crosslinking processes in NLO polymers

A series of photocrosslinkable polymers bearing hyperpolarizable side chain chromophores was synthesized, poled and evaluated on the basis of the thermal stability of Second Harmonic Generation (SHG). Photoinitiation allowed for control of the onset of curing. Crosslinking was monitored by infrared spectroscopy and optimal conversion was achieved by applying a slow temperature ramp during exposure. The ultimate stability of the poled polymers was directly related to the number of crosslinking substituents that were attached to the chromophore pendant group. With two reactive groups per chromophore significant SHG was retained at temperatures above the initial polymer glass transition temperature.

Benzothiazole-based fluorophores of donor-π-acceptor-π-donor type displaying high two-photon absorption

A series of novel heterocycle-based dyes with donor-π-bridge-acceptor- π-bridge-donor (D-π-A-π-D) structural motif, where benzothiazole serves as an electron-withdrawing core, have been designed and synthesized via palladium-catalyzed Sonogashira and Suzuki-type cross-coupling reactions. All the target chromophores show strong one-photon and two-photon excited emission. The maximum two-photon absorption (TPA) cross sections ΔTPA of the prepared derivatives bearing diphenylamino functionalities occur at wavelengths ranging from 760 to 800 nm and are as large as ～900-1100 GM. One- and two-photon absorption characteristics of the title dyes have also been investigated by using density functional theory (DFT) and the structure-property relationships are discussed. The TPA cross sections calculated by means of quadratic response time-dependent DFT using the Coulomb-attenuated CAM-B3LYP functional support the experimentally observed trends within the series, as well as higher ΔTPA values of the title compounds compared to those of analogous fluorene or carbazole-derived dyes. In contrast, the traditional B3LYP functional was not successful in predicting the observed trend of TPA cross sections for systems with different central cores. In general, structural modification of the π-bridge composition by replacement of ethynylene (alkyne) with E-ethenylene (alkene) linkages and/or replacement of dialkylamino electron-donating edge substituents by diarylamino ones results in an increase of ΔTPA values. The combination of large TPA cross sections and high emission quantum yields makes the title benzothiazole-based dyes attractive for applications involving two-photon excited fluorescence (TPEF).