Schiff bases and their complexes with metal ions. Part II. Structures of N-n-butyl-2-hydroxy-1-naphthaldimine and bis[N-n-pentyl-2-hydroxy-1-naphthaldiminato]nickel(II)

The Schiff base ligand (1), [C₁₅H₁₇NO] crystallizes in the monoclinic space group P2₁/c witha=10.054(3),b=10.313(3), c=13.173(4)Å, =107.42(4)°,V=1303.2(7)ų,Z=4,Dx=1.159 g cm^–3, and (MoK)=0.674 cm^–1. The C2-O[1.23(1)Å] and C3–C4 [1.33(2)Å] bond lengths are short, due to its quinoidal structure. In the Schiff base nickel complex (2), [Ni(C₁₆H₁₈NO)₂] the asymmetric unit is comprised of two half-complexes. It crystallizes in the triclinic space group witha=5.124(3),b=16.227(3),c=16.886(4)Å, =95.47(8), =96.00(1), =90.71(4)°,V=1389.6(9) ų,Z=2,Dx=1.289 g cm^–3, and (MoK) =12.1 cm^–1. The coordination of the Ni(II) ions are square planar with bond angles between 87.9(1) and 92.1(1)°. The Ni–O and Ni–N distances are 1.819(2), 1.922(2) and 1.823(2), 1.914(3)Å in these two complexes.     

Synthesis,spectroscopic and spectrophotometric study of BODIPY appended crown ether sensor for ion detection

A novel fluoroionophore compound was synthesized from a boron dipyrromethene (BODIPY) fluorophore and 4′-formylbenzo-15-crown-5 ionophore groups. Photophysical properties of the BODIPY-crown compound were studied with UV–Vis and fluorescence spectroscopy. The effect of metalic cations (Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Ba²⁺, Al³⁺, Fe³⁺, Cu²⁺, Co²⁺, Zn²⁺, Ag⁺, Hg²⁺, Pb²⁺) on the absorption and fluorescence spectra of compound 2 was investigated. Blue shifts were detected in UV–Vis spectra upon addition of some metal ions (Al³⁺ > Fe³⁺ > Na⁺). At the same time, the emission intensity of this complex increased due to binding of Na⁺ ion to the benzo crown cavity. Additionally, a decrease in the intensity of the 630 nm emission peak and an increase in the intensity of the 570 nm emission peak was observed in the fluorescence emission spectra following addition of Al³⁺ and Fe³⁺ ions.     

Determination of α-Cypermethrin from Soil by Using HPTLC

JPC – Journal of Planar Chromatography – Modern TLC - α-Cypermethrin is a synthetic pyrethroid insecticide used to control insects. In soil, α-cypermethrin biodegrades...     

Simultaneous Determination of Benzodiazepines and Ketamine from Alcoholic and Nonalcoholic Beverages by GC-MS in Drug Facilitated Crimes

A GC-MS method with HP-5MS capillary column was developed for the simultaneous determination of underivatized flunitrazepam, clonazepam, alprazolam, diazepam and ketamine from drinks by extraction with chloroform: isopropanol 1:1 (v/v). All linearity ranges were between 50 and 1,000 μg mL^?1 for all compounds both in beer and in peach juice. Limit of detection was between 1.3 and 34.2 μg mL^?1, limit of quantification was between 3.9 and 103.8 μg mL^?1, the range of recoveries was 73.0 and 112.6% for all drugs in both beverages. The reported method was sensitive, rapid, and suitable for the analysis of the spiked drinks as evidence of sexual assault and robbery phenomena.     

Synthesis,spectroscopic studies and structures of square-planar nickel(II) and copper(II) complexes derived from 2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol

Two new nickel(II) [Ni(L)₂] and copper(II) [Cu(L)₂] complexes have been synthesized with bidentate NO donor Schiff base ligand (2-{(Z)-[furan-2-ylmethyl]imino]methyl}-6-methoxyphenol) (HL) and both complexes Ni(L)₂ and Cu(L)₂ have been characterized by elemental analyses, IR, UV–vis, ¹H, ¹³C NMR, mass spectroscopy and room temperature magnetic susceptibility measurement. The tautomeric equilibria (phenol-imine, O–H?N and keto-amine, O?H–N forms) have been systemetically studied by using UV–vis absorption spectra for the ligand HL. The UV–vis spectra of this ligand HL were recorded and commented in polar, non-polar, acidic and basic media. The crystal structures of these complexes have also been determined by using X-ray crystallographic techniques. The complexes Ni(L)₂ and Cu(L)₂ crystallize in the monoclinic space group P2₁/n and P2₁/c with unit cell parameters: a = 10.4552(3) Å and 12.1667(4) Å, b = 8.0121(3) Å and 10.4792(3) Å, c = 13.9625(4) Å and 129.6616(3)Å, V = 1155.22(6) Å³ and 1155.22(6) Å³, D_x = 1.493 and 1.476 g cm^?3 and Z = 2 and 2, respectively. The crystal structures were solved by direct methods and refined by full-matrix least squares to a find R = 0.0377 and 0.0336 of for 2340 and 2402 observed reflections, respectively.     

N,S-, S-, S,S-, <S═O-, and < SO2-Substituted Dienes from Halo-1,3-Butadienes

Mono(thio)substituted dienes 1 gave 3a–g , 5 , and 7 with piperazine derivatives in dichloromethane. Hexachlorobutadiene 14 in a water-ethanol mixture in the presence of sodium hydroxide reacted with thiol 15 to give the mono(thio)substituted thioether 16 and di(thio)substituted thioether 17 . 18 was obtained from the reaction of 16 with m-CPBA in chloroform. 9 was obtained from the reaction of l,2,3,4,4-pentachloro-(1-2-hydroxyethylthio)-1,3- butadiene 8 with 47% HI, and 11 was synthesized from the reaction of 8 with concentrated H₂SO₄ and KBr. Compounds 9 and 11 gave in the reaction with m-CPBA in chloroform 10 , 12 , and 13 , respectively.     

Synthesis,Characterization, and Biological Evaluation of Some Novel Thiosemicarbazones as Possible Antibacterial and Antioxidant Agents

Abstract

The synthesis and characterization of 18 novel thiosemicarbazones have been investigated as part of a research program on development of compounds with antibacterial and antioxidant activities. Among the tested compounds, 2-(4-hydroxybenzylidene)-N-[4-(trifluoromethoxy)phenyl]hydrazine carbothioamide (3g) and 2-(thiophen-2-ylmethylidene)-N-[4-(morpholin-4-yl)phenyl]hydrazine carbothioamide (4b) showed excellent inhibition potency at low concentration (0.5 μg/mL) against Gram-positive pathogens (Enterococcus faecalis and Staphylococcus aureus). All tested compounds were also found to possess antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]     

NOVEL N,S-SUBSTITUTED DIENES BY THE REACTION OF 2-NITROTHIOSUBSTITUTED HALODIENES AND PRIMARY AMINES

Mono(thio)substituted 1a–c gave compounds 3a–c and 5a with o-toluidin (2) and m-toluidin (4) in ether. Compounds 9a–c and 11a, b were obtained from the reaction of compounds 1a–c with p-fluorophenylamine (8) and p-fluorobenzylamine (10). Compounds 7a and 15c were obtained from the reaction of 1a and 1c with p-phenylendiamine (6) and o-phenylendiamine (14). Compound 13c was synthesized from the reaction of compound 1c with benzidine (2).     

Structural and spectroscopic characterization of 2,3-difluorobenzoic acid and 2,4-difluorobenzoic acid with experimental techniques and quantum chemical calculations

In this study, the molecular conformation, vibrational and electronic transition analysis of 2,3-difluorobenzoic acid and 2,4-difluorobenzoic acid (C7H4F2O2) were presented using experimental techniques (FT-IR, FT-Raman and UV) and quantum chemical calculations. FT-IR and FT-Raman spectra in solid state were recorded in the region 4000-400 cm(-1) and 4000-5 cm(-1), respectively. The UV absorption spectra of the compounds that dissolved in ethanol were recorded in the range of 200-800 nm. The structural properties of the molecules in the ground state were calculated using density functional theory (DFT) and second order M?ller-Plesset perturbation theory (MP2) employing 6-311++G(d,p) basis set. Optimized structure of compounds was interpreted and compared with the earlier reported experimental values. The scaled vibrational wavenumbers were compared with experimental results. The complete assignments were performed on the basis of the experimental data and total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. A study on the electronic properties, such as absorption wavelength, excitation energy, dipole moment and frontier molecular orbital energy, were performed by time dependent DFT (TD-DFT) approach. Based on the UV spectra and TD-DFT calculations, the electronic structure and the assignments of the absorption bands of steady compounds were discussed. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecules.