In the current work, we have examined the interaction activities of Pluronic F-68 with cationic conventional, cetyltrimethylammonium bromide (CTAB), and gemini surfactant, pentanediyl-1, 5-bis(dimethylcetylammonium bromide), (16-5-16) by means of surface tension and conductivity measurements. The critical micelle concentration (cmc) values of pure 16-5-16 and CTAB have been evaluated tensiometrically and conductometrically, while the cmc values of pure F-68 and binary mixtures were determined only from the surface tension plots. Various interfacial and micellar parameters including surface excess concentration (Γmax), minimum area per molecule (Amin), surface pressure at cmc (πcmc), packing parameter (p), and interaction parameter (β) have been estimated and discussed in detail. Various thermodynamic parameters including Gibbs free energy of micellization (), standard free energy of adsorption at the air–water interface (), excess free energy of micellization (ΔGex), and molar free energy at the maximum adsorption achieved at cmc (Gmin) have been calculated.
We have investigated the antibacterial activity of some new steroidal thiosemicarbazones and their Pd(II) metal complexes were prepared by the reaction of the thiosemicarbazones with [Pd(DMSO)(2)Cl(2)]. The steroidal thiosemicarbazones were prepared by the reaction of thiosemicarbazides with a steroidal ketone. The structures of these compounds were elucidated by IR, (1)H-NMR, (13)C-NMR, FAB mass spectroscopic methods, elemental analyses and TGA analysis. The antibacterial activity of these compounds were tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria. The results showed that steroidal complexes are better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) as compared to steroidal thiosemicarbazones. Compound Ia displays remarkable antibacterial activity as compared to amoxicillin.
In the title compound, C(22)H(21)NO(5)S, the 2-naphthol group and the thio-phene ring are almost coplanar, with a dihedral angle of 5.75 (7)°. The structure is stabilized by intra-molecular O-H⋯O, O-H⋯N and C-H⋯S, and inter-molecular C-H⋯O hydrogen-bonding inter-actions.
In this approach, low-dimensional facile IAO nanorods were prepared by using the hydrothermal technique, which is efficiently applied to develop a non-enzymatic sensor coated with GCE probe by electrochemical reduction method.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
In the title compound, C(15)H(14)N(2)OS, the pyridinone ring in the fused-ring system is nearly planar (r.m.s. deviation = 0.011 Å) and the cyclo-hexene ring has a twisted half-boat conformation with the methyl-ene C atom adjacent to the methine C atom deviating by 0.592 (7) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.108 Å). The thienyl ring is disordered over two almost coplanar positions of opposite orientation in a 0.649 (4):0.351 (4) ratio, and forms dihedral angles of 51.4 (3) (major component) and 54.2 (3)°, respectively, with the pyridinone ring. In the crystal, inversion-related mol-ecules associate via an eight-membered {⋯HNCO}(2) synthon and these are linked into a linear supra-molecular chain along the a axis by weak π-π inter-actions that occur between centrosymmetrically related pyridinone rings [centroid-centroid distance = 3.889 (2) Å].
In this article, the study of metal-amino acid complex and ninhydrin reaction was examined in gemini micellar solution using a UV-visible spectrophotometric measurement. The role of varying amounts of gemini micellar systems on rate constant of the study was investigated. Initially, rate constant (kψ) enhances, below cmc and levelling-off areas are, then, noticed up to 400 × 10−5 mol dm−3. Later, gemini offers a third region of fast enhancement kψ above 400 × 10−5 mol dm−3. Gemini surfactant series provided more efficient implications on the study than pure water and their monomeric traditional surfactant system. The values of rate constant, kψ, were determined under a set of different experimental reaction situations with the help of a computer-based procedure. Such unfamiliar behaviour developed by gemini micellar solutions was treated by pseudo-phase model of micellar activity. An electrical conductometric measurement was employed to measure critical micellar concentration (cmc) of pure gemini micellar solutions and mixed systems. Several activation parameters were also determined by Eyring’s equation and different constants. Data obtained confirmed that lower values of activation enthalpy (ΔH#) with large negative activation entropy (ΔS#) were attained in gemini than aqueous. A plausible reaction mechanism of the study has been discussed and proposed.
