Effect of Polymer and Surfactant‐Polymer Couples on the Acid-Catalyzed Hydrolysis of Phenyl Urea

The mechanism of the hydrolysis decomposition of phenyl urea in acid, polymer, and surfactant‐polymer media was investigated, the addition‐elimination mechanism with rate determining attack of water at N‐protonated substrate having already been studied. This study has introduced the polymer PEG (MW‐400) and (surfactant‐polymer) (ceteyl trimethyl ammonium bromide‐poly ethylene glycol) (CTAB‐PEG), (cetyl pyridinium bromide‐polyethylene glycol) (CPC‐PEG) (sodium dodecyl sulphate‐poly ethylene glycol) (SDS‐PEG), (Triton X‐100‐poly ethylene glycol) (TX‐100‐PEG), and (Brij35‐poly ethylene glycol) (Brij35‐PEG) in acid media. The results indicate that the presence of polymer and surfactant‐polymer enhances the rate of reaction at 80°C in the presence of 0.9 M H₂SO₄. Kinetic studies show that the reaction obeyed first‐order kinetics. The reaction kinetics can be well explained by micellar catalysis models like the PPIE.     

Extraction of neodymium(III) using binary mixture of Cyanex 272 and Cyanex 921/Cyanex 923 in kerosene

The extraction of Nd(III) using binary mixtures of Cyanex 272 (HA), Cyanex 921/Cyanex 923 (B) in kerosene from nitric acid medium has been investigated. The effect of aqueous phase acidity, extractant concentration, nitrate ion concentration and diluents on the extraction of Nd(III) has been studied. On the basis of slope analysis results, extracted species are proposed as Nd(NO₃)A₂·3HA and Nd(NO₃)₂·A·3HA·B using Cyanex 272 and its mixture with Cyanex 921/Cyanex 923, respectively. With the mixture of 0.1 M Cyanex 272 and 0.1 M Cyanex 923 in kerosene, the extraction of 0.001 M Nd(III) from 0.001 M HNO₃ solution was found to be 83.3 % whereas it was 73.3 % when 0.1 M Cyanex 921 used as synergist under same experimental conditions. The stripping data of Nd(III) from the loaded organic phase containing 0.1 M Cyanex 272 and 0.1 M Cyanex 921/Cyanex 923 with different acids indicated sulphuric acid to be the best stripping agent.     

The Synthesis and Spectroscopic Characterization of Heterobimetallic Bu2Sn(IV) Complexes Derived from Some Chelating Ligands

The interaction of Bu₂Sn(OPrⁱ)₂ with a trifunctional tetradentate Schiff base (LH₃) (where H₃L = HOC₆H₄CH═NCH₃C(CH₂OH)₂) yields the precursor complex Bu₂Sn(LH) 1, which, on equimolar reactions with different metal alkoxides [Al(OPrⁱ)₃, Bu₃Sn(OPrⁱ), Ge(OEt)₄]; Al(Medea)(OPrⁱ) (where Medea = CH₃N- (CH₂CH₂O)₂); and Me₃SiCl in the presence of Et₃N], affords, respectively, the complexes Bu₂Sn(L)Al(OPrⁱ)₂ 2, Bu₂Sn(L)Al(Medea) 3, Bu₂Sn(L)Bu₃Sn 4, Bu₂Sn(L)Ge(OEt)₃ 5, and Bu₂Sn(L)SiMe₃ 6. The reactions of 2 with 2,5-dimethyl-2,5-hexanediol in a 1:1 ratio and with acetylacetone (acacH) in a 1:2 molar ratio afforded derivatives Bu₂Sn(L)Al(OC(CH₃)₂CH₂CH₂C(CH₃)₂ O) 7 and Bu₂Sn(L)Al(acac)₂ 8, respectively. All of the derivatives 1– 8 have been characterized by elemental analyses, molecular weight measurements, and spectroscopic [IR and NMR (¹H, ¹¹⁹Sn, ²⁹Si, and ²⁷Al)] studies.     

Synthesis of selenium bridged metallacycles via oxidative addition of diaryl diselenide across Re-Re bond: Novel one-pot reaction approach

One-pot synthesis of novel M₂E₂L₂ type metallacycles [L(CO)₃Re(μ-SeR)₂Re(CO)₃L] (1-5) was accomplished by oxidative addition of diaryl diselenide to low-valent transition metal carbonyl with monodentate pyridine ligands. In metallacycles 1-5, where L = pyridine ligand, R = C₆H₅, CH₂C₆H₅, the pyridyl groups bonded to metal centres invariably adopted cis conformation due to π-π interaction whereas, in compounds 1a and 2a, the pyridyl ligands were oriented in trans conformation. When bulky phenyl groups are introduced at para position of pyridyl rings, as in case of metallacycle 3, the steric hindrance disrupts the soft interaction and resulted into the expansion of space in between two phenylpyridyl groups and created a void. The Metallacycles 1-5 have been characterised by elemental analysis, NMR, IR, absorption and emission spectroscopic techniques. Molecular structures of 1, 1a, 2, 2a, 3 and 4 were determined by single crystal X-ray diffraction analysis and the structural studies of 1, 2, 3 and 4 revealed that the pyridyl groups attached to the metal centres exhibited cis conformation, while 1a, 2a displayed trans conformation.     

Phosphane-free green protocol for selective nitro reduction with an iron-based catalyst

Iron phthalocyanine with iron sulfate has been successfully applied for high chemo- and regioselective reduction of aromatic nitro compounds to give the corresponding amines in a green solvent system without using any toxic ligand. The catalytic systems were also compatible with a large range of other reducible functional groups, such as keto, acid, amide, ester, halogen, lactone, nitrile, N-benzyl, O-benzyl, hydroxy, and heterocycles. In the present study, dinitro compounds have been regioselectively reduced to the corresponding amines with high yield. In most of the cases the conversion and selectivity was greater than 99% as determined by GC-MS analysis.     

$$Q\bar{Q}$$ ($$Q\in \{b,c\}$$Q∈{b,c}) spectroscopy using the Cornell potential

The mass spectra and decay properties of heavy quarkonia are computed in nonrelativistic quark-antiquark Cornell potential model. We have employed the numerical solution of Schrödinger equation to obtain their mass spectra using only four parameters namely quark mass (\(m_c\), \(m_b\)) and confinement strength (\(A_{c\bar{c}}\), \(A_{b\bar{b}}\)). The spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction are computed perturbatively to determine the mass spectra of excited S, P, D and F states. Digamma, digluon and dilepton decays of these mesons are computed using the model parameters and numerical wave functions. The predicted spectroscopy and decay properties for quarkonia are found to be consistent with available data from experiments, lattice QCD and other theoretical approaches. We also compute mass spectra and life time of the \(B_c\) meson without additional parameters. The computed electromagnetic transition widths of heavy quarkonia and \(B_c\) mesons are in tune with available experimental data and other theoretical approaches.     

Synthesis,Photoluminescence Behavior of Green Light Emitting Tb(III) Complexes and Mechanistic Investigation of Energy Transfer Process

A series of five new terbium(III) ion complexes with 4,4-difluoro-1-phenylbutane-1,3-dione (HDPBD) and anciliary ligands was synthesized. The composition and properties of complexes were analyzed by elemental analysis, IR, NMR, powder X-ray diffaraction, TG-DTG and photoluminescence spectroscopy. These complexes exhibited ligand sensitized green emission at 546 nm associated with ⁵D₄?→?⁷F₅ transitions of terbium ion in the emission spectra. The photoluminescence study manifested that the organic ligands act as antenna and facilitate the absorbed energy to emitting levels of Tb(III) ion efficiently. The enhanced luminescence intensity and decay time of ternary C2-C5 complexes observed due to synergistic effect of anciliary ligands. The CIE color coordinates of complexes came under the green region of chromaticity diagram. The mechanistic investigation of intramolecular energy transfer in the complexes was discussed in detail. These terbium(III) complexes can be thrivingly used as one of the green component in light emitting material and in display devices.

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Graphical Abstract Illustrate the sensitization process of the Tb ion and intramolecular energy transfer process in the Tb³⁺ complex.

     

A unified scheme for flavoured mesons and baryons

The masses of mesons and baryons with various flavour combinations for qˉq, qˉQ, QˉQ, qqq, qqQ, qQQ, QQQ etc. are computed using a confinement scheme based on harmonic approximation with Lorentz scalar plus vector character. The residual two body coulombic interactions and the spin-hyperfine interactions of the confined one gluon exchange effects are perturbatively calculated and added to the confinement energy to get the mass of the hadron. With all the parameters fixed to get ground state masses of hadrons containing like flavour combinations, a parameter free prediction of the leptonic decaywidths of vector mesons and their sizes are being made. Our results on the baryonic and mesonic masses with open flavours and the predictions on the leptonic decay widths are in good agreement with the respective experimental values. Received: 26 February 1998 / Revised version: 1 September 1998     

Study of Anticancer Properties of Graphene Oxide–Metal Oxide Composite

Graphene and graphene oxide (GO) have garnered significant attention due to their exceptional properties. GO, enriched with various functional groups such as epoxy, hydroxyl, and carboxylic groups, has exhibited remarkable potential in biomedical applications. The combination of GO with metals has proven to be a promising platform for cellular imaging, with this study focusing on the preparation of diverse hybrids of GO with metal oxides (GO/MO) and their potential as anticancer agents. In this research, GO is functionalized with MOs like TiO₂, Fe₃O₄, and Cu₂O using specific chemical methods and investigated for the anticancer activity for the application as cancer therapeutic agent. The resulting GO/MO hybrids exhibits favorable thermal and mechanical properties. Moreover, their cytotoxicity against human lung cancer cells is assessed in vitro, revealing the promising anticancer activity of GO/MO hybrids. Notably, the GO/Cu₂O hybrid demonstrates particularly high cytotoxicity in human lung cancer cells.