Structure and conformation of a nickel complex: {2‐Hydroxo‐3‐piperidine‐1‐yl‐methyl‐N,N′(bis‐5‐bromobenzylpropylenediimine)nickel(II)perchlorate}

The title compound, a nickel complex [C₂₃H₂₆N₃O₂Br₂Ni.(ClO₄)] (CCDC 199520) crystallizes in triclinic space group P with the cell parameters a = 10.2560(4), b = 10.8231(4), c = 12.0888(5)Å, α = 99.404(1), β = 99.780(1), γ = 92.252(1)° and V = 1301.49(9)ų. The structure was solved by Patterson method and refined by full‐matrix least‐squares procedures to a final R = 0.0497 using 6287 observed reflections. In the complex, the piperidine ring takes chair conformation and the geometry around the Ni ion is slightly distorted square planar. The dihedral angle between the planes [N‐Ni‐N and O‐Ni‐O] is 9.4(1)°. The chelate ring containing both the nitrogen atoms adopts twisted boat conformation. The molecules in the crystal are stabilized by N‐H…O and C‐H…O types of hydrogen bonds in addition to a C‐H…π interaction. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Chlor­amine‐B sesquihydrate

In the title compound, sodium N‐chloro­benzene­sulfon­amide sesquihydrate, Na⁺·C₆H₅ClNO₂S^?·1.5H₂O, the sodium ion exhibits octahedral coordination by O atoms from three water mol­ecules and by three sulfonyl O atoms of three different N‐­chloro­benzene­sulfon­amide anions. A two‐dimensional polymeric layer consists of units, each comprising two face‐sharing octahedra which share four corners with four other such units, the layer running parallel to the ab plane. The water mol­ecules participate in hydrogen bonds of the types O—H?O, O—H?N and O—H?Cl.     

Multicomponent assembly of anionic and neutral decanuclear copper(II) phosphonate cages

A multicomponent synthetic strategy involving copper(II) ions, tert-butylphosphonic acid (t-BuPO(3)H(2)) and 3-substituted pyrazole ligands has been adopted for the synthesis of soluble molecular copper(II) phosphonates. The use of six different 3-substituted pyrazoles, 3-R-PzH [R = H, Me, CF(3), Ph, 2-pyridyl (2-Py), and 2-methoxyphenyl (2-MeO-C(6)H(4))] as ancillary ligands afforded nine different decanuclear cages, [Cu(5)(μ(3)-OH)(2)(O(3)P-t-Bu)(3)(3-R-Pz)(2)(X)(2)](2)·(Y) where R = H, X = t-BuPO(3)H, and Y = (Et(3)NH(+))(4)(solvent) (1); R = Me, X = 3-MePzH, and Y = solvent (2); R = Me, X = t-BuPO(3)H, and Y = (Et(3)NH(+))(4)(solvent) (3); R = CF(3), X = t-BuPO(3)H, and Y = (Et(3)NH(+))(4)(solvent) (4); R = Ph, X = 3-PhPzH, and Y = solvent (5); R = 2-Py, X = 0.5 MeOH, and Y = solvent (6); R = 2-Py, X = none, and Y = solvent (7); R = 2-Py, X = H(2)O, and Y = (Et(3)NH(+)·PF(6)(-))(2)(solvent) (8); R = 2-MeO-C(6)H(4), X = MeOH or 0.5:0.5 MeOH/H(2)O, and Y = solvent (9). Compounds 1-6, 8, and 9 were isolated using a direct synthetic method which involves the reaction of copper(II) salts and the ligands, while 7 was obtained from an indirect route involving the reaction of preformed copper-pyridylpyrazolate precursor complexes and t-BuPO(3)H(2). The decametallic compounds 1-9 possess a butterfly shaped core. The core of the cages 1, 3, and 4 are tetraanionic and contain more phosphonates than pyrazole ligands, while the other cages are neutral and contain more pyrazoles than phosphonate ligands. Compounds 1-6 have been studied by electrospray ionization-high-resolution mass spectrometry (ESI-HRMS). The decanuclear cage 6 was shown to be a good plasmid modifier.     

Insulin-like antigen of mangrove leaves and its anti-diabetic activity in alloxan-induced diabetic rats

The objective of this study was to evaluate the anti-diabetic potential of three mangrove plants, Rhizophora mucronata, Rhizophora apiculata and Rhizophora annamalayana, and to detect the presence of their insulin-like protein. The in?vivo anti-diabetic experiment was done on male albino Wister rats. Oral administration of 60?mg?kg(-1) leaf powder extract of the three different mangrove plants for 30 days modulated the parameters such as blood glucose, plasma insulin, body weight, total haemoglobin, glycosylated haemoglobin, liver glycogen, plasma and tissue lipids, cholesterol, triglycerides, free fatty acids and phospholipids to normal levels in the alloxan-induced diabetic rats. The anti-diabetic activity of R.?apiculata was more pronounced than that of the other mangrove extracts, but it was on a par with the commercial drug glibenclamide. The presence of an insulin-like protein in the mangrove extracts was detected by SDS-PAGE analysis and confirmed through ELISA. Hence, the anti-diabetic activity and the presence of an insulin-like protein in Rhizophora species were proved scientifically.     

Octa- and hexametallic iron(III)-potassium phosphonate cages

Two new iron(III)-potassium phosphonate cage complexes with {K(2)Fe(6)} and {K(2)Fe(4)} cores are reported. Magnetic studies reveal antiferromagnetic interactions between the Fe(III) centres occur in these cages.     

Carbamic acid 2-trimethylsilylethyl ester as a new ammonia equivalent for palladium-catalyzed amination of aryl halides

Carbamic acid 2-trimethylsilylethyl ester (Teoc-NH₂) serves as an ammonia equivalent in the palladium-catalyzed amination of aryl bromides and aryl chlorides. Anilines with sensitive functional groups can be readily prepared using these amine derivatives.     

Local non-similarity solution to impact of chemical reaction on MHD mixed convection heat and mass transfer flow over porous wedge in the presence of suction / injection

Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by the Runge-Kutta-Gill scheme with the shooting method as well as the local non-similarity method up to the third level of truncation, which are used to reduce the governing partial differential equations into nine ordinary differential equations. The governing boundary layer equations are converted to a dimensionless form by Falkner-Skan transformations. Because of the effect of suction/injection on the wall of the wedge with buoyancy force and variable wall temperature, the flow field is locally non-similar. Numerical calculations up to the third order level of truncation are carried out as a special case for different values of dimensionless parameters. Effects of the magnetic field strength in the presence of chemical reaction with variable wall temperature and concentration on the dimensionless velocity, temperature and concentration profiles are shown graphically.     

Synthesis of gold and silver nanoparticles using purified URAK

This study aims at developing a new eco-friendly process for the synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using purified URAK. URAK is a fibrinolytic enzyme produced by Bacillus cereus NK1. The enzyme was purified and used for the synthesis of AuNPs and AgNPs. The enzyme produced AgNPs when incubated with 1 mM AgNO3 for 24 h and AuNPs when incubated with 1 mM HAuCl4 for 60 h. But when NaOH was added, the synthesis was rapid and occurred within 5 min for AgNPs and 12 h for AuNPs. The synthesized nanoparticles were characterized by a peak at 440 nm and 550 nm in the UV-visible spectrum. TEM analysis showed that AgNPs of the size 60 nm and AuNPs of size 20 nm were synthesized. XRD confirmed the crystalline nature of the nanoparticles and AFM showed the morphology of the nanoparticle to be spherical. FT-IR showed that protein was responsible for the synthesis of the nanoparticles. This process is highly simple, versatile and produces AgNPs and AuNPs in environmental friendly manner. Moreover, the synthesized nanoparticles were found to contain immobilized enzyme. Also, URAK was tested on RAW 264.7 macrophage cell line and was found to be non-cytotoxic until 100 μg/ml.     

N-H…O,C-H… O hydrogen-bonded supramolecular frameworks in 4-fluoroanilinium and dicyclohexylaminium picrate salts

The asymmetric unit of compound (I), 4-fluoroanilinium picrate, C₆H₇NF⁺.C₆H₂N₃O₇^? contain one 4-fluoroanilinium cation and one picrate anion whereas in compound (II), dicyclohexylaminium picrate, C₁₂H₂₂N⁺.C₆H₂N₃O₇^? the asymmetric unit contains two sets of dicyclohexylaminium cation and picrate anion due to conformational difference between the molecules. In (I), all three nitro groups of the picrate anion are positionally disordered over two sites refined to major and minor components. The molecular ions of (I), interlinked through N–H???O and C–H???O hydrogen bonds forming two-dimensional supramolecular sheet along (-1 0 1) plane. Whereas in (II), the symmetry-independent molecules labeled as A and B molecule form independent one-dimensional supramolecular tape extending along (1 1 0) and (1 0 0) direction. The supramolecular tapes are interlinked through C–H???O interaction to form three-dimensional network in the crystalline solid in (II).

     

Surface‐enhanced Raman scattering sensing on black silicon

Reactive ion etching was used to fabricate black‐Si over the entire surface area of 4‐inch Si wafers. After 20 min of the plasma treatment, surface reflection well below 2% was achieved over the 300–1000 nm spectral range. The spikes of the black‐Si substrates were coated by gold, resulting in an island film for surface‐enhanced Raman scattering (SERS) sensing. A detection limit of 1 × 10^?6 M (at count rate > 10² s^?1 . mW^?1) was achieved for rhodamine 6G in aqueous solution when drop cast onto a ～ 100‐nm‐thick Au coating. The sensitivity increases for thicker coatings. A mixed mobile‐on‐immobile platform for SERS sensing is introduced by using dog‐bone Au nanoparticles on the Au/black‐Si substrate. The SERS intensity shows a non‐linear dependence on the solid angle (numerical aperture of excitation/collection optics) for a thick gold coating that exhibits a 10 times higher enhancement. This shows promise for augmented sensitivity in SERS applications.