Shape control is often necessary to tune the optical and electronic properties of nanocrystals (NCs) and is mostly achieved through manipulation of surface ligands and processing conditions. Here we present a versatile synthesis of colloidal CsPbBr 3 perovskite NCs of various shapes (nanorods, nanocubes, and nanoplatelets) from an inexpensive steroidal Cs precursor: cesium cholate (CsCh). Cesium cholate has several advantages over the most commonly used Cs precursor (cesium oleate or Cs 2 CO 3 or CsOAc) such as low cost, nonhygroscopicity, and better reproducibility in the perovskite synthesis. Due to the solubility of this Cs precursor in polar solvents such as methanol, a miniscule polar environment is created during the nucleation and growth of the nanocrystals leading to the serendipitous formation of nanorods at 180 °C, whereas using a biphasic mixture of 1octadecene and methanol, the morphology changes to nanocubes. By lowering the reaction temperature (90 °C), nanoplatelets with 8−9 monolayers thicknesses are formed. These colloidal NCs of a variety of shapes are strongly luminescent with a green emission having narrow emission line widths (16−17 nm) and high quantum yields (96% for nanocubes, 94% for nanoplatelets). Furthermore, hybrid materials of nanocubes and organogel of a dimeric bile acid-derived ester gelator are obtained through coassembly in which nanocubes arrange along nanofibers with stable, sharp, and bright green emission. This enables spatial ordering of nanocubes ranging from micrometer to centimeter scale in thin films, which is crucial for advanced optoelectronic applications. To date, there is no report in the literature on the anisotropic organization of perovskite CsPbBr 3 nanocubes triggered by supramolecular coassembly involving organogel nanofibers.

The development of synthetic scaffolds that nucleate well-folded secondary structures is highly challenging. Herein, we designed and synthesized a series of core-modified peptides (F1, F2, F3, and F4) that fold...

In the last two decades, extending spin memory in NMR has been used for several purposes. Long-lived states (LLS) or singlet states are one of the first spin memory enhancement techniques used. LLS have the potential to extract structural information and intra- and intermolecular interactions of complex systems other than studying slow phenomenon. The motional regime of β-cyclodextrin (β-CD) drug inclusion complexes generally lies in the intermediate region, where ωτ c ≈ 1, and the standard methods of studying these interactions, i.e., NOE and chemical shift monitoring, suffer from insufficient output information. The sensitivity of LLS toward the environmental changes is utilized here to gain insights into the drug assemblies formed by β-CD. One can use change in relaxation of LLS to study the structural changes during complexation. The examples of β-CD with the drugs indomethacin, paracetamol, gliclazide, and CI-933 (a precursor 4-methoxybenzamide) were studied. Indomethacin, paracetamol, and 4-methoxybenzamide show strong interaction through the para-substituted benzene ring, unlike gliclazide. Relaxation of LLS in β-CD–drug complexes is modeled using standard Redfield Relaxation Theory. Computational studies performed support the experimental observations. Docking and molecular dynamics simulation provided the explanation of the relaxation properties of these drug molecules.

Analysing active chemical components of explosives, propellants and post-blast residues have been challenging as it involves massive complexity. The increased use of energetics in various activities like military conflicts, terrorist's activities, and accidental explosions has made the task even more difficult for forensic scientists and environmentalists to analyse post-blast debris. The present studies reported the quantitative analysis of energetic materials present in post-blast soil by 1 H qNMR. The three methods have been used for quantitative studies, i. e. calibration curve method, co-axial stem insert method, and ERETIC method (Electronic to Access In Vivo Concentration). All three methods have been compared with the studies of post-blast residues of explosives such as PETN, Tetryl and TNT. The technique is selective, sensitive, rapid, reliable, and reproduce the result with good accuracy. The study merely requires a nuclear magnetic resonance spectrometer (400 MHz or 500 MHz) as an instrument.

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