Synthesis of Highly Functionalized Isoxazolinediones from One-pot Reaction of Alkylidene Meldrum ’s Acid with Alkyl Isocyanides in the Presence of Arylhydroxylamines

Alkyl isocyanides undergo a smooth reaction with alkylidene Meldrum’s acids in the presence of arylhydroxylamines to produce N ¹-alkyl-2-(3,5-dioxo-2-aryltetrahydro-4-isoxazolyl)alkanamides in high yields.     

Transition energies, wavelengths, oscillator strengths and transition probabilities between 1s, 1sns and 1snp (2?n?9) states for He-like Silicon

Multiconfiguration Hartree-Fock calculations with Breit-Pauli relativistic corrections are reported for electric dipole transition (E1) energies, wavelengths, weighted oscillator strengths and transition probabilities between all of the 1s², 1sns and 1snp (2?n?9) states for He-like silicon. The results are found to compare very well with available other results except Δn=0 due to differences in the calculated excitation energies.     

Solid Phase Extraction and Simultaneous Spectrophotometric Determination of Trace Amounts of Copper and Iron Using Mixture of Ligands

 A novel sensitive and simple method for rapid and selective extraction, preconcentration and determination of iron (as its bathophenanthroline complex) and copper (as its neocuproine complex) using octadecyl silica cartridges and dual wavelength spectrophotometry is presented. The dual wavelength method (533 nm for the iron-bathophenanthroline and 454 nm for the copper-neocuproine as the analytical wavelength) is used to eliminate spectral interferences. Extraction efficiency and the influence of flow rates of sample solution and eluent, pH, amount of neocuproine, bathophenanthroline and hydroxylamine hydrochloride, type and least amount of eluent for elution of iron and copper complexes from cartridge, break-through volume and limit of detection are evaluated. The effects of various cationic and anionic interferences on percent recovery of iron and copper are also studied. Extraction efficiencies >95% are obtained by elution of cartridges with minimal amount of organic solvent. Iron and copper were determined in the range of 3–100 ng mL⁻¹. The limits of detection are 0.98 and 1.13 ng mL⁻¹ for iron and copper, respectively. The proposed method is applied successfully to the determination of both analytes in river, tap and well water samples. Author for correspondence. E-mail: yyamini@modares.ac.ir Received September 18, 2002; accepted December 12, 2002 Published online May 5, 2003     

Unsteady incompressible flow of magnetized aluminium oxide and titanium oxide nanoparticles with blood base fluid

In this investigation, a mixed convective nanoparticles fluid flow over an inclined plate is deliberated. The effects of slip boundary wall and magnetic field are also considered. The dimensionless governing system for the considered problem is attained by implementing recent definitions of fractional derivatives (FD). The generalized solution is obtained through the Laplace Transformation Scheme (LTS) for the momentum and thermal expressions. To improve the novelty and to demonstrate some more physical perception of the stated research work, some remarkable special cases of velocity distribution through CF and AB-fractional derivative concept are addressed, whose daily life implication is well known in the existing literature. Moreover, to evaluate the physical interest of the stated problem, the outcomes of the obtained system graphical illustrations are made by utilizing MATHEMATICA. As a result, we concluded that the aluminium oxide $A{l}_2{O}_3$ nanoparticles show more decaying behavior as compared to titanium oxide $Ti{O}_2$ nanoparticles for temperature and velocity profile. Furthermore, both fields i.e., momentum and thermal distributions are increased with the help of rising estimations parameter. Current results report novel applications in enhancement of heat transfer, thermal engineering, chemical processes, engineering and electronics devices, solar systems, extrusion processes, fission reactions etc.     

Chemical composition and antimicrobial activity of the essential oils of Ferula latisecta and Mozaffariania insignis from Iran

The hydrodistilled oils from the aerial parts of Ferula latisecta and Mozaffariania insignis, which is endemic to Iran, were analyzed by GC and GC/MS. (Z)-Ocimenone (32.4%), (E)-ocimenone (20.3%), and cis-pinocarvone (11.4%) were the main components among the 22 constituents characterized in the oil of F. latisecta, representing 87.7% of the total components detected. Twenty-five compounds were identified in the oil of M. insignis, representing 99.0% of the total oil, with octyl acetate (41.1%), β-pinene (30.3%), and α-pinene (23.9%) as the main constituents. The essential oils were examined for their potential antimicrobial activities. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 561–563, November–December, 2006.     

Diterpenoid Alkaloids of Delphinium buschianum Grossh.

From the aerial parts of Delphinium buschianum Grossh ., collected in Turkey, a new diterpenoid alkaloid 1 , named budelphine, was isolated along with the known diterpenoid alkaloids karakoline ( 2 ), 18‐hydroxy‐14‐O‐methylgadesine ( 3 ), delsoline ( 4 ), lapaconidine ( 5 ), columbianine ( 6 ), 14‐benzoylneoline ( 7 ), and hetisine ( 9 ). The structure of 1 was established on the basis of ¹H‐, ¹³C‐, DEPT, ¹H,¹H‐COSY, NOESY, HSQC, and HMBC NMR studies.     

MASS SPECTROMETRIC STUDIES ON SPIROCYCLIC DERIVATIVES OF CYCLODIPHOSPH(V)AZANES

Abstract

The formation and subsequent fragmentation of spirocyclodiphosph(V)azanes (II-III) has been studied by mass spectrometry using the link-field scan technique and structural inferencies are drawn from these data. ³¹P nmr measurements for compound (III) are also described.     

Contact angle hysteresis in multiphase systems

Contact angle (CA) hysteresis is the difference between the maximum (advancing) and minimum (receding) water CA. Hysteresis is caused by adhesion hysteresis in the solid–water contact area (2D effect) and by pinning of the solid–water–air triple line due to the surface roughness (1D effect). In this work, we show that CA hysteresis is present also in more complex systems, such as an organic liquid (oil) in contact with a solid immersed in water. In order to decouple the 1D and 2D effects, we study CA hysteresis in solid–water–air (droplet), solid–air–water (bubble), solid–water–oil, and solid–water–air–oil systems involving rough and microstructured surfaces. The comparative analysis of these systems allows decoupling the 1D and 2D effects as well as hydrogen bonding and entropic forces (water–air tension) and dispersion forces (oil–air tension).     

Reduction of nitriles into aldehydes using a TMDS/V(O)(OiPr)3 reducing system

A simple and convenient method for the chemoselective reduction of nitriles into aldehydes using a 1,1,3,3-tetramethyldisiloxane (TMDS)/triisopropoxyvanadium(V) oxide reducing system is described. Aromatic as well as aliphatic nitriles are reduced into the corresponding aldehydes in moderate to good yields.