Novel carbazole/fluorene hybrids: host materials for blue phosphorescent OLEDs

[reaction: see text] A series of carbazole/fluorene (CBZm-Fn) hybrids were effectively synthesized through Friedel-Crafts-type substitution of the carbazole rings. These compounds were thermally and morphologically stable host materials for OLED applications. Efficient blue phosphorescent OLEDs were obtained when employing CBZ1-F2 as the host and FIrpic as the guest.     

Vibrational Band Intensities of Hydrocarbons

Abstract

The experimental observables of a vibrational spectrum are depicted either in the form of their positions, i.e., frequency relating the energy required in a given quantum transition, or as the intensities of absorption and scattering related to their transition probabilities. Expressed in terms of molecular parameters, the frequencies depend on the geometry, atomic masses, and intramolecular forces [11 while the band intensities [2] reflect changes in dipole moment (infrared) or polarizabilities (Raman) which are caused during a vibrational displacement and are related to movement of electronic charges within the individual bonds. The mathematical basis for determining vibrational frequencies was well established as early as 1940 by Wilson [3] and others [4, 51. Applying the interpretation of vibrational spectra has become routine in the multitudinous disciplines of chemical literature [6–26]. Accounts of infrared and Raman spectra [27–29], collection of literature [30], and reasonable sets of intramolecular forces [31, 321 are now available for the prediction of normal frequencies of hydrocarbons.     

Laser Raman Spectra of Transition Metal Oxides and Catalysts

Abstract

During recent years the study of the vibrational structure of catalysts by laser Raman spectroscopy (LRS) and of the interfacial properties of adsorbed species on solid surfaces by resonance Raman spectroscopy (RRS) and surface-enhanced Raman spectroscopy (SERS) have comprised one of the major research activities in the area of Raman spectroscopy [1–10] as applied to catalysts [11, 12].     

Synthesis,antimicrobial activity,and molecular docking study of formylnaphthalenyloxymethyl‐triazolyl‐N‐phenylacetamides

In the present study, substituted formylnaphthalenyloxymethyl‐triazolyl‐N‐phenylacetamide derivatives ( 6a – k ) have been designed and synthesized employing click chemistry approach and evaluated for their in vitro antifungal and antibacterial activities. All the newly synthesized compounds were thoroughly characterized by ¹H NMR, ¹³C NMR, and HRMS spectral techniques. Among the screened compounds, 6d , 6e , 6j , and 6k have shown good antifungal and antibacterial activities. Compound 6k has shown very effective antimicrobial activity. We further performed exploratory docking studies on microbial DNA gyrase to rationalize the in vitro biological data and to demonstrate the mechanism of antimicrobial activity. This is the first report to demonstrate the formylnaphthalenyloxymethyl, triazole, and N‐phenylacetamide hybrids as potential antimicrobial agents.     

Efficient Piezoelectric Energy Harvesting from a Discrete Hybrid Bismuth Bromide Ferroelectric Templated by Phosphonium Cation

Bismuth containing hybrid molecular ferroelectrics are receiving tremendous attention in recent years owing to their stable and non-toxic composition. However, these perovskite-like structures are primarily limited to ammonium cations. Herein, we report a new phosphonium based discrete perovskite-like hybrid ferroelectric with a formula [Me(Ph)₃P]₃[Bi₂Br₉] ( MTPBB ) and its mechanical energy harvesting capability. The Polarization-Electric field (P-E) measurements resulted in a well-defined ferroelectric hysteresis loop with a remnant polarization value of 2.1 μC cm⁻². Piezoresponse force microscopy experiments enabled visualization of the ferroelectric domain structure and evaluation of the piezoelectric strain coefficient (d₃₃) for an MTPBB single crystal and thin film sample. Furthermore, flexible devices incorporating MTPBB in polydimethylsiloxane (PDMS) matrix at various concentrations were fabricated and explored for their mechanical energy harvesting properties. The champion device with 20 wt % of MTPBB in PDMS rendered a maximum peak-to-peak open-circuit voltage of 22.9 V and a maximum power density of 7 μW cm⁻² at an optimal load of 4 MΩ. Moreover, the potential of MTPBB -based devices in low power electronics was demonstrated by storing the harvested energy in various electrolytic capacitors.     

Enantioselective LC–ESI–MS/MS method for quantitation of (−)-lumefantrine and (+)-lumefantrine in mice plasma and application to a pharmacokinetic study

We developed and validated a simple, sensitive, selective, and reliable LC–MS/MS–ESI method for the direct quantitation of lumefantrine (LFN) enantiomers [(−)-LFN and (+)-LFN] in mice plasma as per regulatory guideline. LFN enantiomers and carbamazepine (internal standard) were extracted from mice plasma using Strata X SPE (solid-phase extraction) cartridges. Good resolution between enantiomers was achieved on a Chiralpak IA-3 column using an isocratic mobile phase (0.1% of diethyl amine in methanol), which was delivered at a flow rate of 0.8 mL/min. Detection and quantitation were performed using multiple reaction monitoring mode following the transitions m/z 530.27 → 512.30 and 237.00 → 194.00 for LFN enantiomers and the internal standard, respectively, in the positive-ionization mode. The proposed method provided accurate and reproducible results over the linearity range of 2.39–895 ng/mL for each enantiomer. The intra- and inter-day precisions were in the range of 1.03–6.14 and 6.36–8.70 and 2.03–4.88 and 5.82–11.5 for (−)-LFN and (+)-LFN, respectively. Both (−)-LFN and (+)-LFN were found to be stable under different stability conditions. The method was successfully used to delineate stereoselective pharmacokinetics of LFN enantiomers in mice after an oral administration of rac-LFN (20 mg/kg). The pharmacokinetic results indicated that the disposition of LFN enantiomers was stereoselective in mice.     

Validated LC–MS/MS method for quantitation of a selective JAK1 inhibitor,filgotinib in rat plasma,and its application to a pharmacokinetic study in rats

Filgotinib is a selective JAK1 (Janus kinase) inhibitor, filed in Japan for the treatment of rheumatoid arthritis. In this paper, we report a validated liquid chromatography coupled with tandem mass spectrometry for the quantification of filgotinib in rat plasma using tofacitinib as an internal standard (IS) as per the Food and Drug Administration regulatory guidelines. Filgotinib and the IS were extracted from rat plasma using ethyl acetate as an extraction solvent and chromatographed using an isocratic mobile phase (0.2% formic acid:acetonitrile; 20:80, v/v) at a flow rate of 0.9 mL/min on a Gemini C₁₈ column. Filgotinib and the IS were eluted at ~1.31 and 0.89 min, respectively. The MS/MS ion transitions monitored were m/z 426.3 → 291.3 and m/z 313.2 → 149.2 for filgotinib and the IS, respectively. The calibration range was 0.78–1924 ng/mL. No matrix effect and carryover were observed. Intra- and inter-day accuracies and precisions were within the acceptance range. Filgotinib was stable for three freeze–thaw cycles: on bench-top up to 6 h, in an autosampler up to 21 h, and at −80 ° C for 1 month. This novel method has been applied to a pharmacokinetic study in rats.     

Propyl–SO3H functionalized SBA-15: Microwave-mediated green synthesis of biologically active multi-substituted imidazole scaffolds

Research on Chemical Intermediates - Propylsulfonic acid functionalized Santa Barbara Amorphous-15 (SBA-15–Pr–SO3H) catalyst has been synthesized using a surface modification of...