Crystal structure of 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium 2-(4-isobutylphenyl)propanoate: a simple organic salt of racemic ibuprofen

In the title organic salt of ibuprofen with trometamol, C4H12NO3+·C13H17O2−, the carboxylic acid group of ibuprofen has transferred its proton to the amino N atom of trometamol. In the crystal, the trometamol cations are linked via N—H...O hydrogen bonds, forming chains along [001]. To these chains are attached the ibuprofen anions via O—H...O and N—H...O hydrogen bonds. The chains are linked via further N—H...O and O—H...O hydrogen bonds, forming sheets parallel to (100). Two C atoms of the propanoate substituent in the ibuprofen anion are disordered over two sets of sites and were refined with a fixed occupancy ratio of 0.7:0.3

Crystal structure of 7-phenyl-7-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)heptanoate 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium monohydrate: a new solid form of seratrodast

In the title hydrated salt, C4H12NO3+·C22H25O4−·H2O, seratrodast [systematic name: 7-phenyl-7-(2,4,5-trimethyl-3,6-dioxocyclohexa-1,4-dien-1-yl)heptanoic acid] crystallized with trometamol [systematic name: 2-amino-2-(hydroxyméthyl)propane-1,3-diol] to form a monohydrated salt form of seratrodast. The carboxylic acid group of seratrodast has transferred its proton to the amino N atom of trometamol. In the crystal, the trometamol cations are linked to the water molecules and to each other by N—H...O and O—H...O hydrogen bonds forming sheets parallel to (100). The seratrodast anions are linked to both sides of these sheets by O—H...O and C—H...O hydrogen bonds, forming a three-layer two-dimensional structure. After forming the title salt, the solubility of seratrodast was found to be greatly improved

Crystal structure of tetraaquabis(1,3-dimethyl-2,6-dioxo-3,7-dihydro-1H-purin-9-ido)magnesium

The title complex, [Mg(C7H7N4O2)2(H2O)4], lies across an inversion centre and the MgII atom is coordinated in a slightly distorted octahedral environment by four aqua ligands in the equatorial sites and two 1,3-dimethyl-2,6-dioxo-3,7-dihydro-1H-purin-9-ide ligands, through imidazole ring N atoms, in the axial sites. An intramolecular O—H...O hydrogen bond forms an S(7) graph-set motif. In the crystal, O—H...O and O—H...N hydrogen bonds link complex molecules forming a three-dimensional network incorporating R42(8) and R22(18) graph-set motifs

Stability and Antioxidant Activity of Anthocyanins from Flowers of Rhododendron pulchrum Sweet.

The effects of light, temperature, pH, oxidant and reducing agents, metal ions and food additives on the stability of anthocyanins from flowers of Rhododendron pulchrum Sweet., as well as their scavenging capacity for •OH, O2-• and DPPH• free radicals and reducing power were investigated. The results showed that the anthocyanins from flowers of R. pulchrum were relatively stable in the room with natural light, at temperature lower than 45℃, and in the solution with pH ≤ 4. The addition of Na+, K+ Ca2+ metal ions, glucose, sodium benzoate, acetic acid and salt had little effect, but Cu2+, Zn2+, Fe3+, Al3+, starch and sodium glutamate showed adverse effects on the stability of the anthocyanins. The anthocyanins from flowers of R. pulchrum had a good antioxidant effect, and their scavenging capacity for •OH, O2-•, DPPH• was better than that of the same concentration of Vc

A Differential Phase-Modulated Interferometer with Rotational Error Compensation for Precision Displacement Measurement

In this paper, a differential phase-modulated interferometer (DPMI) is proposed to compensate for the rotational error for precision displacement measurement. In DPMI, a reference interferometer sharing the same reference arm with the measurement interferometer is constructed. Using the two interferometers to differentially measure the displacement, the unbalanced environmental disturbance on the measurement can be minimized. An integrated 2 × 2 array photodetector (APD) is adopted in DPMI. Based on APD with differential wavefront sensing (DWS) technology, the rotation angle can be detected and compensated. Therefore, precision displacement without rotational error and unbalanced environmental disturbance can be achieved. Three confirmatory experiments were performed, and the experimental results show that the maximum displacement drift is reduced from 902.9 nm to 16.3 nm in 100 min stability test, the standard deviations between the pitch and yaw angles obtained by DPMI and Renishaw interferometer are 1.68 × 10−5° and 1.86 × 10−5°, respectively, and the maximum deviation between the measurement result of DPMI and the stage positioning before and after angle compensation is reduced from 5.207 μm to about 0.719 μm

Preparation of Functionalized Magnetic Fe3O4@Au@polydopamine Nanocomposites and Their Application for Copper(II) Removal

Polydopamine (PDA) displays many striking properties of naturally occurring melanin in optics, electricity, and biocompatibility. Another valuable feature of polydopamine lies in its chemical structure that incorporates many functional groups such as amine, catechol and imine. In this study, a nanocomposite of magnetic Fe3O4@Au@polydopamine nanopaticles (Fe3O4@Au@ PDA MNPs) was synthesized. Carboxyl functionalized Fe3O4@Au nanoparticles (NPs) were successfully embedded in a layer of PDA through dopamine oxypolymerization in alkaline solution. Through the investigation of adsorption behavior to Cu(II), combined with high sensitive electrochemical detection, the as-prepared magnetic nanocomposites (MNPs) have been successfully applied in the separation and analysis of Cu(II). The experimental parameters of temperature, Cu(II) concentration and pH were optimized. Results showed that the as-prepared MNPs can reach saturation adsorption after adsorbing 2 h in neutral environment. Furthermore, the as-prepared MNPs can be easily regenerated by temperature control and exhibits a good selectivity compared to other metal ions. The prepared Fe3O4@Au@PDA MNPs are expected to act as a kind of adsorbent for Cu(II) deep removal from contaminated waters

Significant Expansion of the Solid State Landscape of Salicylic Acid Based on Charge-Assisted Hydrogen Bonding Interactions

Successful cocrystallization between a salicylate salt with salicylic acid and chemically distinct carboxylic acids suggests the robustness of the carboxylic acid-carboxylate supramolecular synthon. This type of robust synthon involving charge-assisted hydrogen bonding interactions has the potential to significantly expand the solid-state landscape of ionizable molecules