A series of diphenylamine-fluorenone derivatives as potential fluorescent probes for neuroblastoma cell staining

Effect of substituting donors on the hole mobility of hole transporting materials in perovskite solar cells: a DFT study

Several hole-transporting materials (HTMs) have been designed by incorporating different types of π-conjugation group such as long chain aliphatic alkenes and condensed aromatic rings of benzene and thiophene and their derivatives on both sides between the planar core and donor of a reference HTM. Various electronic, optical, and dynamic properties have been calculated by using DFT, TDDFT, and Marcus theory. In this study, all the designed HTMs show a lower HOMO energy level and match well with the perovskite absorbers. Inserting condensed rings results in better hole mobility compared to aliphatic double bonds. It is found that the charge transfer integral is the dominant factor which mainly influences the hole mobility in our studied HTMs. Other factors such as hole reorganization energy, hole hopping rate, and centroid distance have a minor effect on hole mobility. Thus, this study is expected to provide guidance for the design and synthesis of new HTMs with increased hole mobility.

Synthesis of a light-responsive platinum curcumin complex, chemical and biological investigations and delivery to tumor cells by means of polymeric nanoparticles

Platinum-based anticancer drugs are common in chemotherapy, but problems such as systemic toxicity and acquired resistance of some tumors hamper their clinical applications and therapeutic efficacy. It is necessary to synthesize Pt-based drugs and explore strategies to reduce side effects and improve pharmacokinetic profiles. Photo-responsive chemotherapeutics have emerged as an alternative strategy against several cancers, as photoactivation offers spatial selectivity and fewer side effects. Here, we combine chemical synthesis and nanotechnology to create a multifunctional platinum drug delivery system based on the novel metal complex [Pt(ppy)(curc)] (ppy = deprotonated 2-phenylpyridine, curc = deprotonated curcumin)] embodying the naturally occurring bioactive molecule, curcumin. The ultrasonication method coupled with the layer-by-layer technology was employed to produce nanocolloids, which demonstrated a good biocompatibility, higher solubility in aqueous solution, stability, large drug loading, and good biological activity in comparison with the free drug. In vitro release experiments revealed that the polymeric nanoformulation is relatively stable under physiological conditions (pH = 7.4 and 37 °C) but sensitive to acidic environments (pH = 5.6 and 37 °C) which would trigger the release of the loaded drug. Our approach modifies the bioavailability of this Pt-based drug increasing its therapeutic action in terms of both cytotoxic and anti-metastasis effects.

Insight into the binding interactions of fluorenone-pendent Schiff base with calf thymus DNA

A novel fluorenone appended Schiff base (L) has been synthesized and utilized for studying the binding interactions with Calf Thymus DNA (ct-DNA). The mechanism of binding with ct-DNA was explored by employing various spectroscopic techniques viz. UV-Vis absorption spectroscopy, fluorescence emission spectroscopy, gel-electrophoresis, circular dichroism (CD), melting studies, viscosity arrays and molecular modelling methodology. The interpretation of UV-vis absorbance spectra pointed to binding of L within minor groove of ct-DNA with the binding constant of K_b = 0.15 × 10⁴ M^-1. Dye-displacement studies with Rhodamine-B (RhB) and Ethylene Bromide (EB) in fluorescence spectroscopy verified the groove binding mode of interaction between L and ct-DNA. Melting studies, circular dichroism, and viscosity studies further elucidated the binding modes of L with ct-DNA. Thermodynamic variable measurements taken at various temperatures such as ΔG^⁰, ΔH^⁰, and ΔS^⁰ revealed that hydrophobic forces played a significant role in the binding process. The meticulous computational interaction demonstrated by molecular docking confirmed the minor groove binding of L with ct-DNA.

N,N-Bis(4′-(hexyloxy)-[1,1′-biphenyl]-4-yl)thiophen-2-amine

N,N-Diarylthiophen-2-amine units are of great interest for the synthesis of optoelectronic devices. In this communication, N,N-bis (4′-(hexyloxy)-[1,1′-biphenyl]-4-yl)thiophen-2-amine was obtained by means of a Buchwald–Hartwig cross-coupling reaction of bis(4′-(hexyloxy)-[1,1′-biphenyl]-4-yl)amine and 2-bromothiophene in the presence of tris(dibenzylideneacetone)dipalladium(0), tri-tert-butyl phosphine and sodium tert-butanolate. The structure of newly synthesized compounds was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy and mass-spectrometry.

Control of Electron Transfer Processes in Multidimensional Arylamine-Based Mixed-Valence Compounds by Molecular Backbone Design

Four trigonal topology compounds with three diarylamines redox centers and dibenzofulvene as core bridge have been synthesized. Their radical cations exhibit appealing intramolecular electron transfer pathways between three redox centers, depending on their position on the core bridge. By changing such positions (on either 2,7- or 3,6-), and the length of the bridge, the control of the intramolecular electron transfer pathways was achieved through the electron self-exchange route. These processes were investigated by absorption spectroscopy, electron paramagnetic resonance spectroscopy, and (time-dependent) density functional theory calculations. Hole mobility measurements were carried out as well, to correlate the intramolecular electron transfer with the hole-transporting ability for possible applications in optoelectronic devices.

An investigation of broadband optical nonlinear absorption and transient nonlinear refraction in a fluorenone-based compound

A novel fluorenone derivative, FO52, is designed and synthesized.

High-Performance Electrofluorochromic Switching Devices Using a Novel Arylamine-Fluorene Redox-Active Fluorophore

Fluorescent light modulation by small electric potentials has gained huge interest in the past few years. This phenomenon, called electrofluorochromism, is of the utmost importance for applications in optoelectronic devices. Huge efforts are being addressed to developing electrofluorochromic systems with improved performances. One of the most critical issue is their low cyclability, which hampers their widespread use. It mostly depends on the intrinsic reversibility of the electroactive/fluorophore molecular system and on device architecture. Here we show a novel fluorene-based mixed-valence electrofluorochromic system that allows direct electrofluorochromic switching and exhibits incomparable electrochemical reversibility and device cyclability of more than 10 000 cycles.