Cationic Crown Ether Complexes of Germanium(II)

Fit for a king : Cationic complexes of Ge^II can be prepared by using crown ethers to stabilize and protect the germanium center. Three different crown ethers were employed: [12]crown‐4 (see structure, Ge teal, O red, C gray), [15]crown‐5, and [18]crown‐6. The structures of the cationic complexes depend on the cavity size of the crown ether and on the substituent on germanium.

     

Universal canonical black hole entropy

Nonrotating black holes in three and four dimensions are shown to possess a canonical entropy obeying the Bekenstein-Hawking area law together with a leading correction (for large horizon areas) given by the logarithm of the area with a universal finite negative coefficient, provided one assumes that the quantum black hole mass spectrum has a power-law relation with the quantum area spectrum found in nonperturbative canonical quantum general relativity. The thermal instability associated with asymptotically flat black holes appears in the appropriate domain for the index characterizing this power-law relation, where the canonical entropy (free energy) is seen to turn complex.     

Azobenzene-based Photochromic Delivery Vehicles for Ions and Small Molecules

Molecular switches have been used as delivery vehicles for various molecular and ionic species. The ones that reversibly operate with light are arguably the best candidates for the purpose as they can be operated using light. The two states of these photoswitchable systems often possess remarkable differences in terms of their structural features and electronic properties. Photochromic systems with the appropriate embellishment of functionalities at suitable positions have thus been used as photoresponsive receptors. The use of light-driven alterations of the structural features has led to differential molecular recognition with these switchable host molecules. In this article, we discuss the use of such supramolecular systems as the delivery vehicles for ions and molecules that started with the pioneering work by Shinkai back in 1979. This review will explicitly cover the development from 2001 to 2022 with some past background and the future prospects of the field.     

Measurement of neutron dose from p+181Ta reaction at different proton energies via LET spectrometry

Journal of Radioanalytical and Nuclear Chemistry - While measuring the neutron dose in accelerator radiation environment using CR-39 detector for radiation protection purpose, LET (linear energy...     

Induced activity from Cu and SS-304 targets on proton bombardment

Journal of Radioanalytical and Nuclear Chemistry - Presently accelerator facilities emphasizes on generating charged particles with enhanced energy and flux. The radiation protection practices at...     

ChemInform Abstract: Structure and Stability of Water Chains (H2O)n,n = 5—20

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.