Design,synthesis, characterization,and physical property determination of a new ionic liquid: the preparation of triazolo-pyrimidines at room temperature under metal-free conditions

Research on Chemical Intermediates - A new ionic liquid is synthesized, and its chemical structure is characterized by FTIR, 1D NMR and 2D NMR, and mass analyses. The thermal behavior and thermal...     

Time-dependent magnetothermoelastic creep modeling of FGM spheres using method of successive elastic solution

Magnetothermoelastic creep behavior of thick-walled spheres made of functionally graded materials (FGM) placed in uniform magnetic and distributed temperature fields and subjected to an internal pressure is investigated using method of successive elastic solution. The material creep, magnetic and mechanical properties through the radial graded direction are assumed to obey the simple power law variation. Using equations of equilibrium, stress-strain and strain-displacement a differential equation, containing creep strains, for displacement is obtained. A semi-analytical method in conjunction with the Mendelson’s method of successive elastic solution has been developed to obtain history of stresses and strains. History of stresses, strains and effective creep strain rate from their initial elastic distribution at zero time up to 55 years are presented in this paper. Stresses, strains and effective creep strain rate are changing in time with a decreasing rate so that after almost 50 years the time-dependent solution approaches the steady state condition when there is no distinction between stresses and strains at 50 and 55 years.     

Combined hollow fiber-based liquid-liquid-liquid microextraction and in-situ differential pulse voltammetry to improve selectivity, sensitivity, and interference elimination in electrochemical analysis

In this paper, a combined hollow fiber-based liquid three-phase microextraction and voltammetric method are applied for the first time as a highly selective and sensitive method of electrochemical analysis. Desipramine, used as a model compound was extracted from 8 mL aqueous solution (donor phase, 0.10 mol L⁻¹ NaOH) through a thin phase of propyl benzoate inside the pores of a polypropylene hollow fiber and finally into a 10 μL acidic acceptor solution inside the hollow fiber. Three microelectrodes designed and constructed for the purposes of this study were placed into the two ends of the hollow fiber inside the acceptor solution, and voltammetric analysis was performed in-situ during the extraction. After 15 min, the final stable signal was used for analytical applications. Under the optimized conditions, an enrichment factor of 301 was achieved and the relative standard deviation (R.S.D.) of the method was 6.2% (n = 5). The calibration curve was obtained in the range of 5-5000 nmol L⁻¹ with a reasonable linearity (R² > 0.988) and the limit of detection (LOD) was found to be 0.8 nmol L⁻¹. Finally, the applicability of the proposed method was evaluated by extraction and determination of desipramine in plasma and urine samples without any dilutions.     

Chemical composition of the essential oil of aerial parts of Haussknechtia elymaitica Boiss. from Iran: a good natural source for trans-asaron

The chemical composition of the essential oil of Haussknechtia elymaitica Boiss. was investigated by capillary GC and GC/MS for the first time. Twelve components were identified which accounting for 99.7% of the oil composition. The major compounds were trans-asarone (59.9%), trans-methyl isoeugenol (22.4%), α-zingiberene (7.96%), β-sesquiphellandrene (4.7%) and β-bisabolene (4.3%). The first three compounds considered as the main components of the essential oil were isolated and characterised by spectroscopic techniques.     

Synthesis and Reactivity of Functionalized Binary and Ternary Thiometallate Complexes [(RT)4S6], [(RSn)3S4]2−, [(RT)2(CuPPh3)6S6], and [(RSn)6(OMe)6Cu2S6]4− (R=C2H4COOH,CMe2CH2COMe; T=Ge,Sn)

Caged chalcogens : A series of novel, functionalized T_nS_m cages (T=Ge, Sn; n/m=4:6, 3:4) with terminal COO(H) or COMe groups were synthesized and show further reactivity toward Cu^I complexes (an example of which is shown here) and to hydrazines. This led to the generation of functionalized Cu/T/S clusters or the formation of Schiff bases at the C?O groups, respectively, with or without further fragmentation of the T/S core.

     

Spectrophotometric study of interaction of iodine with 4'-aminobenzo-15-crown-5 in chloroform, dichloromethane and 1,2-dichloroethane solutions

The formation of charge transfer complex between 4'-aminobenzo-15-crown-5 (AB15C5) and iodine is investigated spectrophotometrically in chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solutions at 25 degrees C. The continuous variation method clearly revealed the formation of 1:1 charge transfer complex in solution. The observed time dependence of the charge transfer band and subsequent formation of I 3- in solution were related to the slow transformation of the initially formed 1:1 AB15C5.I2 outer complex to an inner electron donor-acceptor (EDA) complex, followed by fast reaction of the inner complex with iodine to form a triiodide ion. The pseudo-first-order rate constants for the transformation process were evaluated from the absorbance-time data and found to vary in the order of 1,2-DCE>DCM>CHCl3. The values of the formation constant, KDA, for each complex are evaluated from Benesi-Hilebrand equation. Stability of the resulting complex in three solvents was also found to vary in the order of 1,2-DCE>DCM>CHCl3.     

Spectroscopic, Thermal and Structural Studies of Cocrystals of 2,2′-Diamino-4,4′-bis(1,3-thiazole) with 2,5-Bis(4-pyridyl)-3,4-Diaza-2,4-Hexadiene and 1,2-Bis(4-pyridyl)Ethylenediamine

Abstract  

Two cocrystals of 2,2′-diamino-4,4′-bis(1,3-thiazole) (DABTZ) with 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene (bpdh) and 1,2-bis(4-pyridyl)ethylenediamine (bpen) {[(DABTZ)(bpdh)] and [(DABTZ)(bpen)], respectively} have been synthesized and characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR spectroscopy and were studied by thermal analysis and X-ray crystallography. Self-assembly of these compounds in the solid state is likely caused by hydrogen bonding with minor contributions from π–π stacking, C–H···π and possibly charge transfer interactions.