Triphenylamine Backbone Research Articles

Rational design of fluorescent nanoparticles: From wavelength redshift to increased water solubility for stable and high-resolution imaging of latent fingerprints

Efficient and accurate visual identification of latent fingerprints is crucial in areas such as criminal investigation and information security. Aggregation-induced luminescence (AIE) fluorescent materials are widely used in this field because of their strong fluorescence and easy functionalization. They have attracted significant interest and emerged as a promising area since the introduction of the AIE concept. Here a new water-soluble fluorescent nanoparticle, flu-p-DITPA, through amphiphilic self-assembly with amphiphilic polymers macro-CTA-mPEG2000 (P1) and exhibits typical AIE properties. The core molecule, indo-DITPA, derived from the triphenylamine backbone, was obtained through rational molecular design and theoretical calculations, and the calculated results were confirmed with experimental results. The photophysical properties of indo-DITPA and flu-p-DITPA have been meticulously studied, revealing their remarkable characteristics. Taking advantage of their favorable photophysical properties, good water solubility, and biocompatibility, the researchers have devised a simple yet effective method for visualizing latent fingerprints (LFPs) with high resolution under UV light. This method enables the easy decoding of latent fingerprint information at primary, secondary, and tertiary levels. Importantly, this technique is simple, rapid, and user-friendly, marking a significant step forward in the field of forensic science and fingerprint analysis.

Synthesis, Characterization and Photovoltaic Properties of Polyplatinaynes with Side Chain Functionalization by Different Electron-Accepting Group

Four new solution-processable platinum-containing polyynes functionalized with triphenylamine backbone and different acceptor fragment in the side chain were synthesized and characterized by spectroscopic, thermal and optical methods. The main- and side-chains show different absorption features in the solar spectrum, resulting in broad absorption coverage of the whole visible region. By changing the acceptor group in the side chain, the photophysical properties including energy levels, absorption wavelength and bandgap of the polymers were finely tuned. As the strength of electron acceptor is increased, the power conversion efficiency (PCE) of organic polymer solar cells fabricated with these polymers as electron donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as electron acceptor was increased. PCE of 1.35% can be obtained from solar cell based on the polyplatinayne with the dicyanovinyl side group under illumination of an AM 1.5 solar cell simulator in a 1:4 (polymer:PCBM) blend ratio.Graphical

“On–off” fluorescence detection of exposed phosgene via pyrazine ring formation on a triphenyl amine backbone supplemented with a theoretical approach and practical environmental applications

A fluorescent probe ADM has been developed for the selective detection of phosgene through a unique cyclization pathway producing a substituted pyrazine derivative attached to a triphenyl amine backbone.

Acylhydrazone Functionalized Triphenylamine-Based Fluorescent Probe for Cu2+: Tunable Structures of Conjugated Bridge and Its Practical Application.

Novel fluorescent probes were constructed for the convenient and rapid analysis of Cu2+ ions, taking advantages of the the triphenylamine backbone as chromophore and acylhydrazone group as the Cu2+ recognition site. Especially, probe T2 could act as a dual-channel probe towards Cu2+ through both fluorescent and colorimetric method. Through the fluorescent method, the detection limit of probe T2 was calculated to be as low as 90 nmol/L and there was a good linear relationship between the intensity change and the concentration of Cu2+ ions. By virtue of the two-phase liquid-liquid extraction method, probe T2 could be successfully applied in practical extraction and separation of Cu2+. Furthermore, by applying a "turn-off-turn-on" circle, compound T2 could act as a sensitive probe towards S2- anions through the indirect approach and the detection limit of complex T2-Cu2+ for S2- anion was found to be 110 nmol/L.

Effect of fluorine substitution on properties of hole-transporting materials for perovskite solar cells

In photovoltaic technologies, hole-transporting materials (HTMs) play a critical role in realizing highly efficient performance of perovskite solar cells (PSCs). Herein, a series of fluorine substituted small molecules based on triphenylamine backbone are designed by controlling fluorine atoms number and position. A comprehensive study on the structural modification is carried out to reveal the effect of fluorine substitution of HTMs. The energy level alignment, reorganization energy and the charge-transport properties are explored based on Quantum-chemical calculations. It is found that all difluorinated molecules have lower HOMO levels, which indicates that perovskite solar cells with two fluorine substituted hole-transporting materials may have higher open-circuit voltages. Moreover, the UV–vis absorption spectra of the studied molecules are slightly red-shifted with the increase of fluorine atoms. To further understand the effect of fluorine substitution on the hole transport properties, the hole mobilities of all HTMs are evaluated quantitatively using the Marcus theory and Einstein relation. The calculated results show that difluorinated molecules TPB-m-2F exhibit relatively higher hole mobility owing to efficient intermolecular interactions. As for monofluorinated molecules TPB-1F-a and TPB-1F-b, TPB-1F-a with fluorine atoms substituted on the inside position exhibit higher hole-transporting performance. Overall, we conclude that suitable modification of fluorine substitution is expected to improve the electrochemical and hole transport property of HTMs. We hope our theoretical investigation provide useful information for further improving the photovoltaic performance of PSCs.

Investigation of photophysical properties of triphenylamine phenylethenyl derivatives containing tertiary amine groups

Triphenylamine (TPA) compounds are versatile charge transport materials, demonstrating high emission efficiency and interesting interactions in solid state. Their spectroscopic emission parameters highly depend on surrounding medium owning to strong CT character in solution. Although TPA compounds demonstrate good charge transport capabilities, further optimization via molecular design is required. In this work, various TPA molecular systems with varying number of additional dimethylamine (dMA) and phenylethenyl (PE) substituents were thoroughly investigated. Additionally, influence of quaternarization of tertiary amine groups in the triphenylamine backbone on emission and electronic properties was analyzed. TPA-dMA compounds demonstrated aggregation induced emission enhancement with high emission efficiency and excellent (μh = 4.7·10−3 cm2V−1s−1) charge transport in the solid state. Quaternarization of tertiary amine groups in the triphenylamine backbone has led to emission and electronic properties in the wide 400–700 nm spectral region.

Spectroelectrochemical studies of the redox active tris[4-(triazol-1-yl)phenyl]amine linker and redox state manipulation of Mn(ii)/Cu(ii) coordination frameworks.

This work describes the successful incorporation of a redox active linker, tris(4-(1H-1,2,4-triazol-1-yl)phenyl)amine (TTPA) into Mn(ii)/Cu(ii) based coordination frameworks. Solution state in situ spectroelectrochemistry of EPR and UV/Vis/NIR of the TTPA ligand were measured to gain a deeper understanding of the charge delocalization of the triphenylamine backbone. The assignments of the absorption bands for the radical cations in UV/Vis/NIR spectroelectrochemistry were supported by DFT calculations. For Mn(ii)/Cu(ii) based coordination frameworks, solid state electrochemical and in situ spectroelectrochemical methods were applied to elucidate the accessible redox states and the optical properties of the frameworks. The findings provide a basic comprehension of the interconversion of different redox states and how an electroactive framework can be potentially used in applications of electrochromic and optical devices.

Influence of Heterocyclic Spacer and End Substitution on Hole Transporting Properties Based on Triphenylamine Derivatives: Theoretical Investigation

Hybrid organic–inorganic halide–perovskite based solar cells have achieved outstanding progress, approaching one of the most competitive photovoltaic technologies. One of the hot topics is to develop inexpensive and efficient hole transporting materials to improve the performance of devices for practical applications. In this paper, we theoretically design a series of hole transporting materials based on triphenylamine backbone through varying the spacer and the end substitution. The properties of frontier molecular orbital, ionization potential, reorganization energy, and charge mobility have been calculated and analyzed. The results show that the spacer and the end functional groups strongly influence the molecular geometry, stacking, electron density distribution, and especially hole mobility. The best hole transporting material with furan as spacer and hydroxyl or methoxyl as substitution is proposed due to its highest hole transporting mobility induced by the planar conformation and tight π–π stackin...

Synthesis, Characterization and Photophysical Studies of D-π-A Based Conjugated Triphenylamine Derivatives

We synthesized a new series of intramolecular charge transfer (ICT) molecules by attaching very strong electron-withdrawing groups to a triphenylamine backbone. ICT interactions can be found for all the triphenylamine (TPA) derivatives due to the electron withdrawing properties of the cyanide on the end terminal triphenylamine moiety. When introducing the electron withdrawing group on the TPA moiety giving rise to efficient emission tuning from blue to green in polar solvents, due to the increase in ICT interactions which results in the bathochromically shifted ICT band observed. Further, from these results, we found that all the compounds exhibit intensive ICT interactions leading to substantial extension of their absorption spectral response.

Reaction-based probe for hydrogen sulfite: dual-channel and good ratiometric response.

We designed and synthesized a new series of intramolecular charge transfer (ICT) molecules (compounds T1, T2 and T3) by attaching various electron-donating thiophene groups to the triphenylamine backbone with aldehyde group as the electron acceptor. Based on the nucleophilic addition reaction between hydrogen sulfite and aldehyde, all compounds could act as ratiometric optical probe for hydrogen sulfite and displayed efficient chromogenic and fluorogenic signaling. Upon the addition of hydrogen sulfite anions, probe T3 displayed apparent fluorescent color changes from yellowish-green to blue, with a large emission wavelength shift (Δλ = 120nm). T3 responded to hydrogen sulfite with high sensitivity and the detection limit was determined to be as low as 0.9μM. At the same time, apparent changes in UV-vis spectra could also be observed. By virtue of the special nucleophilic addition reaction with aldehyde, T3 displayed high selectivity over other anions. Copyright © 2016 John Wiley & Sons, Ltd.

Mechano-fluorochromic Pt(II) Luminogen and Its Cysteine Recognition.

A new triphenylamine-based organometallic Pt(II) luminogen (1) and its analogous organic compound (2) are reported. The molecules are decorated with aldehyde functionality to improve their photophysical properties by utilising donor-acceptor interactions. The single crystal X-ray structure analysis of Pt(II) analogue 1 revealed that the neighbouring molecules were loosely organised by weak intermolecular C-H⋅⋅⋅π interactions. Because of the twisted nature of the triphenylamine backbone the compounds showed aggregation-induced emission enhancement in THF/water mixture. Due to their loose crystal packing, upon application of external stimuli these luminogens exhibited mechano-fluorochromic behaviour. The crystalline forms of the compounds displayed a more superior emission efficiency than the grinded samples. Moreover, the compounds showed crystallization-induced emission enhancement (CIEE) and exhibited chemodosimetric response towards cysteine under physiological condition.

Electron-rich triphenylamine-based sensors for picric acid detection.

This paper demonstrates the role of solvent in selectivity and sensitivity of a series of electron-rich compounds for the detection of trace amounts of picric acid. Two new electron-rich fluorescent esters (6, 7) containing a triphenylamine backbone as well as their analogous carboxylic acids (8, 9) have been synthesized and characterized. Fluorescent triphenylamine coupled with an ethynyl moiety constitutes π-electron-rich selective and sensitive probes for electron-deficient picric acid (PA). In solution, the high sensitivity of all the sensors toward PA can be attributed to a combined effect of the ground-state charge-transfer complex formation and resonance energy transfer between the sensor and analyte. The acids 8 and 9 also showed enhanced sensitivity for nitroaromatics in the solid state, and their enhanced sensitivity could be attributed to exciton migration due to close proximity of the neighboring acid molecules, as evident from the X-ray diffraction study. The compounds were found to be quite sensitive for the detection of trace amount of nitroaromatics in solution, solid, and contact mode.

ChemInform Abstract: Facile Preparation of Macrocycles with Triphenylamine Backbone via C—N Coupling Reaction.

AbstractThe one‐pot, palladium‐catalyzed oligomerization yields a new type of cyclic compound.

Tunable light‐harvesting polymers containing embedded dipolar chromophores for polymer solar cell applications

AbstractA series of light‐harvesting conjugated polymers were designed and synthesized for polymer solar cells. These newly designed polymers comprise an unusual two‐dimensional conjugated structure with an electron‐rich thiophene–triphenylamine backbone and stable planar indacenodithiophene π‐bridges terminated with tunable electron acceptors. It was found that the electron‐withdrawing strength of the acceptor could be used to manipulate the energy level of the lowest unoccupied molecular orbital and bandgap (as much as 0.3 eV), generating derivatives with complementary absorbance in the visible spectrum. This approach provides great flexibility in fine tuning the electronic and optical properties of the resultant polymers and facilitates the investigation of how these chemical modifications alter the subsequent photovoltaic properties of these materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Facile Preparation of Macrocycles with Triphenylamine Backbone via C–N Coupling Reaction

Abstract Cyclic oligomers composed of triphenylamine backbone were conveniently prepared via palladium-catalyzed one-pot synthesis. The condition for the preparation was optimized to give the cyclic oligomers with large ring sizes in good yield up to 73.7%. The type of base for the reaction dramatically influenced the yield of cyclic oligomers, and potassium tert-butoxide was the most effective for the cyclization. The composition of the cyclic oligomers was determined by high-performance liquid chromatography (HPLC) as a mixture of pentamer, hexamer, and heptamer. The cyclic pentamer was easily isolated by only recrystallization from tert-butyl methyl ether.

Synthesis, Crystal Structures, and Photophysical Properties of Triphenylamine-Based Multicyano Derivatives

A new series of intramolecular charge transfer (ICT) molecules were synthesized by attaching various strong electron-withdrawing groups to a triphenylamine backbone. Relationships between chemical structures and optoelectronic properties of these compounds were investigated with X-ray diffraction, cyclic voltammetry, absorption spectroscopy, and density functional theory calculations. It is shown that the compounds exhibit intensive ICT interactions leading to substantial extension of their absorption spectral response, which may be potentially used for efficient solar cells.

Novel Silafluorene-Based Conjugated Polymers with Pendant Acceptor Groups for High Performance Solar Cells

Two low-band-gap conjugated polymers, PSiFDCN and PSiFDTA, which consist of alternating silafluorene and triphenylamine backbone and different pendant acceptor groups (malononitrile and 1,3-diethyl-2-thiobarbituric acid) with styrylthiophene as π-bridge, were synthesized and characterized. By changing the acceptor groups in side chain, the energy levels, absorption spectra, and band gaps of the resulted polymers were effectively tuned. As the strength of the acceptors increases, the band gap reduces from 1.83 eV for PSiFDCN to 1.74 eV for PSiFDTA. Bulk heterojunction solar cells with these polymers as electron donor and (6,6)-phenyl-C71-butyric acid methyl ester (PC71BM) as electron acceptor exhibit high Voc (>0.85 V) and power conversion efficiency (PCE) of 2.50% and 3.15% for PSiFDCN and PSiFDTA, respectively.