Bis- and tris-naphthoimidazolium derivatives for the fluorescent recognition of ATP and GTP in 100% aqueous solution

Naphthoimidazolium groups can form unique ionic hydrogen bonds with anions as imidazolium moieties, and in addition, they are fluorescent, so no further elaborative synthesis is needed to introduce a fluorescent group. In this paper, three naphthoimidazolium derivatives were synthesized and studied for the recognition of nucleotides. Compound 1 composed of a single naphthoimidazolium group and quaternary ammonium group did not show any significant fluorescent changes with various anions and nucleotides, such as ATP, GTP, CTP, TTP, UTP, ADP and AMP. A tripodal compound 3 bearing three naphthoimidazolium groups and three quaternary ammonium groups, respectively, showed large fluorescence enhancements with UTP, CTP and TTP and moderate fluorescence enhancements with ATP and pyrophosphate and a fluorescence quenching effect with GTP. On the other hand, compound 2 bearing two naphthoimidazolium groups and two quaternary ammonium groups displayed a selective fluorescence enhancement with ATP and a selective fluorescence quenching effect with GTP in 100% aqueous solution.     

Subordinated α-stable Ornstein–Uhlenbeck process as a tool for financial data description

The classical financial models are based on the standard Brownian diffusion-type processes. However, in the exhibition of some real market data (like interest or exchange rates) we observe characteristic periods of constant values. Moreover, in the case of financial data, the assumption of normality is often unsatisfied. In such cases the popular Vasi?ek model, that is a mathematical system describing the evolution of interest rates based on the Ornstein–Uhlenbeck process, seems not to be applicable. Therefore, we propose an alternative approach based on a combination of the popular Ornstein–Uhlenbeck process with a stable distribution and subdiffusion systems that demonstrate such characteristic behavior. The probability density function of the proposed process can be described by a Fokker–Planck type equation and therefore it can be examined as an extension of the basic Ornstein–Uhlenbeck model. In this paper, we propose the parameters’ estimation method and calibrate the subordinated Vasi?ek model to the interest rate data.     

A Self-Assembled ATP Probe for Melanoma Cell Imaging

In this investigation, a new terpyridine metal complex was developed as a probe for selective detection of ATP and imaging of melanoma cells. The probe takes advantage of the ability of the metal complex to be transformed to its imaging competent turn-on state through assembly with ATP.     

Molecularly Tailored Lithium–Arene Complex Enables Chemical Prelithiation of High-Capacity Lithium-Ion Battery Anodes

Prelithiation is of great interest to Li-ion battery manufacturers as a strategy for compensating for the loss of active Li during initial cycling of a battery, which would otherwise degrade its available energy density. Solution-based chemical prelithiation using a reductive chemical promises unparalleled reaction homogeneity and simplicity. However, the chemicals applied so far cannot dope active Li in Si-based high-capacity anodes but merely form solid–electrolyte interphases, leading to only partial mitigation of the cycle irreversibility. Herein, we show that a molecularly engineered Li–arene complex with a sufficiently low redox potential drives active Li accommodation in Si-based anodes to provide an ideal Li content in a full cell. Fine control over the prelithiation degree and spatial uniformity of active Li throughout the electrodes are achieved by managing time and temperature during immersion, promising both fidelity and low cost of the process for large-scale integration.     

An Activatable AIEgen Probe for High-Fidelity Monitoring of Overexpressed Tumor Enzyme Activity and Its Application to Surgical Tumor Excision

Monitoring fluctuations in enzyme overexpression facilitates early tumor detection and excision. An AIEgen probe (DQM-ALP) for the imaging of alkaline phosphatase (ALP) activity was synthesized. The probe consists of a quinoline-malononitrile (QM) core decorated with hydrophilic phosphate groups as ALP-recognition units. The rapid liberation of DQM-OH aggregates in the presence of ALP resulted in aggregation-induced fluorescence. The up-regulation of ALP expression in tumor cells was imaged using DQM-ALP. The probe permeated into 3D cervical and liver tumor spheroids for imaging spatially heterogeneous ALP activity with high spatial resolution on a two-photon microscopy platform, providing the fluorescence-guided recognition of sub-millimeter tumorigenesis. DQM-ALP enabled differentiation between tumor and normal tissue ex vivo and in vivo, suggesting that the probe may serve as a powerful tool to assist surgeons during tumor resection.     

Unique hydrogen bonds between 9-anthracenyl hydrogen and anions

Unique hydrogen bonds of the 9-H of anthracene moieties in hosts 1 and 2 with fluoride and pyrophosphate ions were observed on the basis of the (1)H NMR experiments. Furthermore, hosts 1 and 2 act as a colorimetric sensor and a fluorescent chemosensor for the recognition of fluoride ion, respectively.     

Aminobromination of unsaturated phosphonates

Unexpected syn beta-amino-alpha-bromination of unsaturated phosphonates was observed under typical Sharpless AA reaction conditions with excess N-bromoacetamide.     

New imidazolium systems bearing two pyrene groups as fluorescent chemosensors for anions and anion induced logic gates

Two new imidazolium systems bearing two pyrene groups have been synthesized and the binding properties of these hosts were examined via fluorescent changes. The fluorescent changes of host 2 upon the addition of anions were also utilized as a NOR logic gate and an INH logic gate.     

Quinoxaline-imidazolium receptors for unique sensing of pyrophosphate and acetate by charge transfer

[structure: see text] Quinoxaline derivatives (1-4) bearing two imidazolium moieties are found to strongly bind anions and show unique charge-transfer fluorescent responses to pyrophosphate and acetate, whereas they show excimer formation with other anions. Anion-binding studies are investigated with fluorescence and 1H NMR analysis, single-crystal X-ray analysis, and theoretical calculations.