Search

In this paper, we report the possibility of using the X-ray powder diffraction (XRPD) technique to detect gamma-hydroxybutyric acid (GHB) in the form of its sodium salt in different beverages, but because it is not possible to freely buy GHB, beta-hydroxybutyric acid (BHB) and its sodium salt (NaBHB) were used as a model to fine-tune an X-ray diffraction method for the qualitative analysis of the sodium salt of GHB. The method requires only a small quantity of beverage and an easy sample preparation that consists only of the addition of NaOH to the drink and a subsequent drying step. The dry residue obtained can be easily analyzed with XRPD using a single-crystal X-ray diffractometer, which exploits its high sensitivity and allows for very fast pattern collection. Several beverages with different NaBHB:NaOH molar ratios were tested, and the results showed that NaBHB was detected in all drinks analyzed when the NaBHB:NaOH molar ratio was 1:50, using a characteristic peak at very low 2θ values, which also permitted the detection of its presence in complex beverage matrices. Moreover, depending on the amount of NaOH added, shifting and/or splitting of the characteristic NaBHB salt peak was observed, and the origin of this behavior was investigated. [ABSTRACT FROM AUTHOR]

Chitosan is a biodegradable polymer derived from chitin, which is a versatile material for various biological applications due to its attractive properties such as biocompatibility, biodegradability, and non-toxicity. Furthermore, chitosan possesses Second Harmonic Generation (SHG) properties that are useful for biosensing applications. In this work, we explored the possibility of exploiting chitosan-based nanospheres as SHG-based biosensors, and also as carriers of 89Sr radionuclide, an Active Pharmaceutical Ingredient (API) for radiopharmaceutical treatments in cancer therapy. To opportunely load the Sr ion on the nanospheres, we used a fructose-based Metal–Organic Framework, with the formula [Sr(C6H12O6)2(H2O)2]Cl2·H2O, because the sugar was able to drive the Sr ions on the chitosan matrix. Sr-loaded chitosan nanospheres were synthesized, characterized, and their SHG response was measured. The results encouraged us to propose the nanospheres for theranostic purposes, i.e., valuable for both therapeutic and diagnostic applications at the same time. [ABSTRACT FROM AUTHOR]

The complex [Fe.sub.2][(CO).sub.7]([H.sub.2]CCC[H.sub.2]) (1) is obtained starting from a variety of functionalized alkynes that can release [C.sub.3] fragments during the reactions with [Fe.sub.3][(CO).sub.12] or Fe[(CO).sub.5] in C[H.sub.3]OH-KOH solutions. Owing to the oily nature of 1, it was reacted with triphenylphosphine, and the structure of the resulting title compound (1a) has been determined by X-ray analysis. Complex 1a shows a new coordination mode of a [H.sub.2]C=C=C[H.sub.2] ligand to a diiron centre and is, to our knowledge, unprecedented. We have also found that 1 (and 1a) are by-products, and not intermediates in the formation of complex 3. A discussion of the possible reaction pathways is given. Key words: iron carbonyls, alkynols, CO and methanol activation, acetyl and acetate complexes, allenyl iron complexes, crystal structure. Le complexe [Fe.sub.2][(CO).sub.7]([H.sub.2]CCC[H.sub.2]) (1) a ete prepare a partir d'une variete d'alcynes fonctionnalises qui peuvent perdre des fragments en [C.sub.3] au cours de reactions avec du [Fe.sub.3][(CO).sub.12] ou du Fe[(CO).sub.5] dans des solutions de C[H.sub.3]OH-KOH. En raison de la nature huileuse du compose 1, on l'a fait reagir avec de la triphenylphosphine et on a fait appel a la diffraction des rayons X pour determiner la structure cristalline du produit qui en resulte et qui est mentionne dans le titre (1a). Le complexe 1a presente un nouveau mode de coordination du ligand [H.sub.2]C=C=C[H.sub.2] au centre difer qui, a notre connaissance etait inconnu jusqu'a maintenant. On a aussi trouve que les composes 1 (et 1a) sont des sous-produits et non pas des intermediaires dans la formation du complexe 3. On presente une discussion des voies reactionnelles potentielles. Mots cles : fer carbonyles, alkynols, activation du CO et du methanol, complexes acetyles et acetates, complexes d'allenyl fer, structure cristalline. [Traduit par la Redaction], Introduction Propargyl alcohols react with [M.sub.3][(CO).sub.12] carbonyls (M = Fe, Ru, or Os) both under thermal (hydrocarbons, reflux) and basic conditions (C[H.sub.3]OH-KOH solution, followed by acidification with HCl) undergoing different [...]

An analysis of the experimental electron density of Mn(sub 2)(CO)(sub 10), carried out according to the Bader's quantum theory of atoms in molecules for the Mn - Mn Mn - CO bonds, are determined by a multipole model from accurate X-ray data measured at 120 K. Topological parameters of the metal - metal and metal - ligand bonds are reported.

Using the equilibrium properties of the Cu(II) cation in the presence of chelating ligands and the characteristics of the dicyanoaurate anion, we were able to obtain a family of 5 bimetallic Cu–Au compounds with supramolecular architectures based on aurophilic interactions. These compounds have been tested for vapochromism at different temperatures and pressures. One of the obtained products shows reversible vapochromism in the presence of ammonia and the process has been studied using IR and UV-vis absorption spectroscopy. The behaviour at variable temperatures and pressures of these crystalline materials has been investigated, showing the effect of these two variables. Moreover, an isosymmetric phase transition at 1.2 GPa has been detected and studied with Raman and SC-XRD. Finally, Cu–Au molecular building blocks have been used to construct cocrystals, opening the way for the crystal engineering of new multimetallic compounds based on aurophilic interactions. [ABSTRACT FROM AUTHOR]