O-Alkyl Trithiophosphate Derivatives of Triorganotin(IV) and S-Alkyl Trithiophosphate Derivatives of Diorganotin(IV) Chloride

Reactions of triorganotin chlorides with potassium salt of O-alkyl trithiophosphate [ROP(S)(SK)₂; R = Me, Prⁱ, Ph] in 2:1 molar ratio in anhydrous benzene yield triorganotin O-alkyl trithiophosphate of the type ROP(S) [SSnR′₃]₂ R = Me, Prⁱ; Ph, R′ = Prⁿ, Buⁿ, Ph] which are found to be monomeric in nature. These complexes are soluble in common organic solvents. Similar reactions of diorganotin chloride with dipotassium salt of S-alkyl trithiophosphate yield diorganotin-S-alkyl trithiophosphate of the type [(RS)P(O)S₂]₂SnR′₂; R = Me, Prⁱ; R′ = Me, Et, Ph, which also are found to be monomeric in nature and are soluble in common organic solvents. The newly synthesized derivatives have been characterized by physicochemical and spectroscopic techniques, IR, NMR (¹H, ³¹P, and ¹¹⁹Sn).     

Polymerization of Methyl Methacrylate Using Acridone-Bromine Combination as the Photoinitiator

The photopolymerization of methyl methacrylate (MMA) in visible light was studied at 40°C using the acridone-bromine (acridone-Br₂) combination as the photoinitiator. The polymerization was found to proceed via a free radical mechanism, and the radical generation process was considered to follow an initial complexation reaction between monomer and each initiator component (acridone and Br₂), followed by further interaction between these two initiator-monomer complexes. Kinetic data indicated a lower-order dependence of R on initiator concentrations (initiator exponent < 0.5). Initiator-dependent chain termination was signifi-cant along with the usual bimolecular mode of chain termination. The monomer exponent varied from about 1.00 to 2.00, depending on the nature of solvents used. The nonidealities in this system were also analyzed.     

Use of an Internal Keto-Imino Compound as the Photoinitiator in the Polymerization of Methyl Methacrylate

Photopolymerization of MMA in visible light was studied at 40°C using acridone as the photoinitiator. The polymerization was found to proceed via a free radical mechanism and the radical generation process was considered to follow an initial complexation reaction between monomer and acridone. Kinetic data indicated a lower order dependence of R_p on the initiator concentration (initiator exponent < 0.5). Initiator-dependent chain termination was significant along with the usual bimolecular mode of chain termination. The monomer exponent varied from about 1.0 to 1.5, depending on the nature of the solvent used. The nonidealities in this case were also analyzed.     

Viscosity Behavior of Some Synthetic Polypeptides at Low Concentration

The viscosity of poly(γ-benzyl L-glutamate)(PBLG), poly -carbobenzoxy-L-lysine (PCBL), polyglycine (PG), and fivetricopolypeptides (glu^x-lys^y -gly^z) was studied as a function of concentration at 25°C. The solvents used include two random coil solvents, a theta solvent and a helicogenic solvent. The Huggins plots of all the systems except polyglycine showed anomalously high reduced viscosity values at low concentration of solutions. A variation of 20°C in the temperature of some of the systems did not show any marked effect on the abnormality in the Huggins plots. Various factors likely to cause abnormality were considered; disentanglement of the polypeptide chains appeared to be the prime factor responsible for the anomalous rise in the reduced viscosity.     

Kinetic Investigation on the Photopolymerization of Methyl Methacrylate Using Iodine Trichloride as Initiator

The photopolymerization of MMA in visible light was studied at 45°C using IC1₃ as the photoinitiator. The initiator exponent was found to be 0.16 and the monomer exponent varied between 1.0 to 1.50, depending on the nature of the solvent. Analysis of the data revealed that the polymerization was induced by a free radical mechanism. Nonideality of the kinetics was explained on the basis of 1) Monomer-dependent chain initiation and 2) Initiator-dependent chain termination via degradative initiator transfer.     

Vacuum ultraviolet spectroscopy of Pr in CaAl4O7, LaMgAl11O19 and SrLaAlO4

The vacuum ultraviolet spectroscopy of Pr³⁺ doped CaAl₄O₇, LaMgAl₁₁O₁₉ and SrLaAlO₄ is reported. It appears that whenever the aluminate host lattice is excited directly, mainly exciton and 4f²–4f² [³P₀] Pr³⁺ emission are observed. When the excitation energy is lower, Pr³⁺ ions are excited selectively and 4f5d–4f² emission dominates. These observations can be explained by assuming that energy transfer from the host lattice to the Pr³⁺ ion takes place preferentially via an intermediate exciton state with an energy too low to reach the energetic Pr³⁺ 4f5d excited states.     

One-dimensional description of multidimensional electron transfer reactions in condensed phase

We derive a one-dimensional energy diffusion equation for describing the dynamics of multidimensional electron transfer reactions in condensed phase, which is conceptually simpler and computationally more economic than the conventional approaches. We also obtain an analytical expression for the rate of electron transfer reactions for a general one-dimensional effective potential as well as an energy dependent diffusitivity. As an illustrative example, we consider application to electron transfer in a contact ion pair system modeled through harmonic potentials consisting of two slow classical modes and a high frequency vibrational mode for which the numerical results calculated using the proposed one-dimensional approach are shown to be in good agreement with experimental results. The energy diffusion equation and the rate expression for electron transfer obtained from the present theory, therefore, open up the possibility of describing the dynamics of electron transfer in complex systems, through a simpler approach.     

N,N′‐Dicyclohexyl‐N‐[4‐(1H‐indol‐3‐yl)butanoyl]urea

The title compound, C₂₅H₃₅N₃O₂, is a novel urea derivative. Pairs of intermolecular N—H...O hydrogen bonds join the molecules into centrosymmetric R₂²(12) and R₂²(18) dimeric rings, which are alternately linked into one‐dimensional polymeric chains along the [010] direction. The parallel chains are connected via C—H...O hydrogen bonds to generate a two‐dimensional framework structure parallel to the (001) plane. The title compound was also modelled by solid‐state density functional theory (DFT) calculations. A comparison of the molecular conformation and hydrogen‐bond geometry obtained from the X‐ray structure analysis and the theoretical study clearly indicates that the DFT calculation agrees closely with the X‐ray structure.     

Design,synthesis, molecular docking,and biological studies of novel phytoestrogen-tanaproget hybrids

A diverse range of novel and highly functionalized flavonoid-based tanaproget hybrids were synthesized and evaluated in vitro for their antimicrobial and antiproliferative activities. Novel products were synthesized in good yields (81–95%) under Pd-catalyzed reaction from bromo flavones and tanaproget boronic acids within 18–20 min at 60 °C. Bioassay results exhibited excellent activities against both hormone-dependent and hormone-independent human breast cancer cells (MCF-7, MDA-MB-231, DU-145, PC-3, and HeLa). Among them, compounds 4e, 9a, 9c, 9e, 9 g, 9 h, 9 m, and 9n displayed excellent activity. Compounds 4d, 4o, and 9o were found equally potent against C. albicans compared to fluconazole. Compound 5c showed better antibacterial activity against S. aureus. Compounds 5a, 9i, 9o, and 10c have shown admirable antibacterial activity against E. coli.