Diastereotopic groups in two new single-enanti-omer structures (R2)P(O)[NH-(+)CH(C2H5)(C6H5)] (R = OC6H5 and C6H5).

The crystal structures of two single-enanti-omer compounds, i.e. diphenyl [(R)-(+)-α-ethyl-benzyl-amido]-phosphate, C21H22NO3P or (C6H5O)2P(O)[NH-(R)-(+)CH(C2H5)(C6H5)] (I), and N-[(R)-(+)-α-ethyl-benz-yl]-P,P-di-phenyl-phosphinic amide, C21H22NOP or (C6H5)2P(O)[NH-R-(+)CH(C2H5)(C6H5)] (II), were studied. The different environments at the phospho-rus atoms, (O)2P(O)(N) and (C)2P(O)(N), allow the P=O/P-N bond strengths to be compared, as well as the N-H⋯O=P hydrogen-bond strengths, and P=O/N-H vibrations. The following characteristics related to diastereotopic C6H5O/C6H5 groups in I/II were considered: geometry parameters, contributions to the crystal packing, solution 13C/1H NMR chemical shifts, conformations, and NMR coupling constants. The phospho-rus-carbon coupling constants nJ PC (n = 2 and 3) in I and mJ PC (m = 1, 2, 3 and 4) in II were evaluated. For a comparative study, chiral analogous structures were retrieved from the Cambridge Structural Database (CSD) and their geometries and conformations are discussed.

Multifunctional Tetracycline-Loaded Silica-Coated Core-Shell Magnetic Nanoparticles: Antibacterial, Antibiofilm, and Cytotoxic Activities.

In the current study, the physicochemical and biological properties of tetracycline-loaded core-shell nanoparticles (Tet/Ni0.5Co0.5Fe2O4/SiO2 and Tet/CoFe2O4/SiO2) were investigated. The antibacterial activity of nanoparticles alone and in combination with tetracycline was investigated against a number of Gram-positive and Gram-negative bacteria for determining minimum inhibitory concentration (MIC) values. The MIC of Tet/Ni0.5Co0.5Fe2O4/SiO2 nanoparticles turned out to be significantly higher than that of Tet/CoFe2O4/SiO2 nanoparticles. Furthermore, Tet/Ni0.5Co0.5Fe2O4/SiO2 nanoparticles exhibited potent antibiofilm activity against pathogenic bacteria compared to Tet/CoFe2O4/SiO2 nanoparticles. The drug delivery potential of both carriers was assessed in vitro up to 124 h at different pH levels and it was found that the drug release rate was increased in acidic conditions. The cytotoxicity of nanoparticles was evaluated against a skin cancer cell line (melanoma A375) and a normal cell line (HFF). Our findings showed that Tet/Ni0.5Co0.5Fe2O4/SiO2 had greater cytotoxicity than CoFe2O4/SiO2 against the A375 cell line, whereas both synthesized nanoparticles had no significant cytotoxic effects on the normal cell line. Nonetheless, the biocompatibility of nanoparticles was assessed in vivo and the interaction of nanoparticles with the kidney was scrutinized up to 14 days. The overall results of the present study implied that the synthesized multifunctional magnetic nanoparticles with drug delivery potential, anticancer activity, and antibacterial activity are promising for biomedical applications.

Synthesis of graphene by in situ catalytic chemical vapor deposition of reed as a carbon source for VOC adsorption.

Few-layer graphene was synthesized by in situ catalytic carbon vapor deposition (CCVD) method, using reed as a carbon source and Ni, Cu, and Mg salts as the catalyst compounds. The synthesized graphene was also used for adsorption of VOCs. Furthermore, the effect of organic additives, sorbitol, and citric acid on catalyst compounds was investigated by temperature-programmed reduction analysis (H2-TPR). The products' properties were characterized by thermo-gravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) surface area analysis. TEM and FE-SEM images confirmed the formation of graphene sheets. Activation of the graphene by phosphoric acid at 500 °C and then by CO2 at 800 °C increased the surface area from 298 to 568 m2/g. Gasoline working capacity of the activated graphene was 65.24 g/ladsorbent. Graphical abstract Few-layer graphene was synthesized by in situ catalytic carbon vapor deposition (CCVD) method using reed as a carbon source and Ni, Cu, and Mg salts as the catalyst compounds and used for adsorption of VOCs.

Charge-transfer complexes of 4-nitrocatechol with some amino alcohols.

Charge-transfer (CT) complexes formed from the reactions of 4-nitropyrocatechol (4-nCat) as an electron acceptor with four amino alcohols: 2-aminoethanol, 1-amino-2-propanol, 4-aminobutanol and N-(2-hydroxyethyl)-1,3-diaminopropane (NHEDAP) as electron donors, have been studied spectrophotometrically in H(2)O and H(2)O/EtOH at 20, 25, 30, 35 and 40 degrees C. The calculated values of the oscillator strength and transition moment confirm the formation of CT-complexes. The thermodynamic and spectroscopic parameters were also evaluated for the formation of CT-complexes. The equilibrium constants ranged from 9.00 to 2.20 l mol(-1) (M(-1)). These interactions are exothermic and have relatively large standard enthalpy and entropy changes (DeltaH values ranged from -15.58 to -3.10 kJ mol(-1); DeltaS ranged from 26.81 to -3.25 J K(-1)mol(-1)). The solid CT-complexes have been synthesized and characterized by IR, NMR, mass spectrometry and thermal analysis. The photometric titration curves and other spectrometric data for the reactions indicated that the data obtained refer to the formation of 1:1 charge-transfer complex of [(4-nCat) (NHEDAP)] and 1:2 charge-transfer complexes of other amino alcohols [(4-nCat) (amino alcohol)(2)]. The effect of alkali and alkaline earth metals on increasing the equilibrium constant of the CT-complexation was also investigated.

Dopaminium perchlorate.

IN THE TITLE COMPOUND [SYSTEMATIC NAME: 2-(3,4-dihydroxy-phen-yl)ethanaminium perchlorate], C(8)H(12)NO(2) (+)·ClO(4) (-), the cations and anions are linked into three-dimensional structure via inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.