Search results for "PYRIDINE"

Preparation of 4-substituted 1,3-oxathiolan-5-onesviathe sulphenium ion intermediate generated by the pummerer rearrangement

1993

4-Substituted 1,3-oxathiolan-5-ones have been synthesized via the Pummerer rearrangement from the S-oxide of the parent molecule. The 4,5-dione is obtained in the presence of pyridine N-oxide.

Poly(2-vinylpyridine)-Based Polymers as an Efficient Affinity Material for the Detection of Airborne Phenol

2015

Phenol is an omnipresent compound in various situations. Its acute toxicity makes alternative tracing methods desirable. Highly potent affinity materials based on polyvinyl pyridine allow an efficient tracing of this particular airborne compound. Their performance over, for example, benzene is tremendously superior. In combination with a simple cyclodextrin derivative an array allows differentiation among such aromatic competitors. Owing to the high affinity of these polymers for phenol, quartz microbalance-based tracing is able to detect phenol below the parts per million range. This was previously not possible with other affinity materials.

Molecularly imprinted polymers (MIPs) against uracils: Functional monomer design, monomer-template interactions in solution and MIP performance in ch…

2002

AbstractThe interaction of N1-substituted uracils (cyclohexyl (1) and benzyl (2)) with three polymerisable recognition elements, the novel monomers 9-(3/4-vinylbenzyl)adenine (3) and 2,6-diamino-9-(3/4-vinylbenzyl)purine (4) and the previously synthesised monomer 2,6-bis(acrylamido)pyridine (5), has been studied via1H NMR in deuterio-chloroform solution. MIPs against (2) have been prepared using each of the monomers and tested in the chromatographic mode. The effect of the number and type of hydrogen bonds formed between the templates and the functional monomers is reflected in the values of the apparent association constants obtained from the solution study and by the performance of the su…

<strong>Synthesis and Platinum (II) Complexes of Different Polyazacyclophane Receptors</strong>

2015

During the last years, research on coordination chemistry of platinum has aroused great interest due to their potential biological applications. Herein, we report the interaction of PtCI42- with different polyazacyclophanes containing a pyridine unit as aromatic spacer. Formation of complexes has been studied by 1H and 195Pt NMR spectroscopy. Analysis of the recorded spectra of D2O solutions containing L and PtCl42- in a 1:1 molar ratio at acidic pH shows the evolution with time of the 1H and 195Pt signals. Different crystal structures have been solved by X-ray diffraction analysis. At acidic pHs, the metal ion is coordinated by the central amino group of the macrocyclic cavity and three ch…

Redox and Photochemistry of Bis(terpyridine)ruthenium(II) Amino Acids and Their Amide Conjugates – from Understanding to Applications (Eur. J. Inorg.…

2014

Synthesis and Characterization of Extended Bis(terpyridine)ruthenium Amino Acids

2009

(Oligopyridine)ruthenium(II) complexes have been widely used in dye sensitized solar cells and other sophisticated optical devices due to their outstanding photophysical properties and their chemical stability. Herein, we describe the longitudinal extension of our previously reported bis(terpyridine)ruthenium(II) amino acid [Ru(tpy–NH2)(tpy–COOH)]2+ (tpy = 4′-substituted 2,2′:6′,2″-terpyridine) by insertion of para-phenylene spacers –C6H4– between the terpyridine and the functional groups. The influence of the para-phenylene spacer on the absorption and emission properties is investigated using UV/Vis absorption and emission spectroscopy and is discussed within a qualitative molecular orbit…

Crystal structure of (E)-4-methoxy-2-{[(5-methylpyridin-2-yl)imino]methyl}phenol

2015

The molecule of the title Schiff base compound, C14H14N2O2, displays anEconformation with respect the imine C=N double bond. The molecule is approximately planar, with the dihedral angle formed by the planes of the pyridine and benzene rings being 5.72 (6)°. There is an intramolecular hydrogen bond involving the phenolic H and imine N atoms.

Theoretical and Spectroscopic Studies On Imino-carbon Palladated Pyridine-2-carbaldimines

1987

Abstract Ab initio LCAO-MO-SCF calculations on the model compounds C 5 H 4 N-2-C(R 1 )=NH [R 1 = H ( 2c ) and R 1 = trans -PdCl(PH 3 ) 2 ( 4c )] indicate that the E - trans conformation is favored over the E - cis one by 16.9 kJ mol −1 for 2c and by 25.0 kJ mol −1 for 4c . One of the factors which stabilizes the E-trans arrangement for 4c is a weak bonding interaction between the palladium center and the pyridine nitrogen. On going from 2c to 4c a slight charge enrichment on the pyridine carbons and a more pronounced one on the nitrogen atoms is computed, whereas the charge density of the imino carbon atom is decreased. In 4c no π contribution to the PdC bond is observed. Protonation of th…

Ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates: synthesis and spectroscopic investigation

2007

The synthesis of novel ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates, meso-[( B 15 C 5)4 Por ] Ru ( CO )( MeOH ) (1) and meso-[( B 15 C 5)4 Por ] Ru ( L )2 (2)-(4) (meso-[( B 15 C 5)4 Por ]2-= 5,10,15,20-tetrakis-(benzo-15-crown-5)-porphyrinato-dianion; L = pyridine (py), pyrazine (pyz), 4,4′-bipyridyl (4,4′-bpy)), where CO and MeOH , or two N -donor ligands are axially coordinated to the central metal, are reported. The metalation of the free ligand performed by the reaction of Ru 3( CO )12 with meso-[( B 15 C 5)4 Por ] H 2 in 1,2,4-trichlorobenzene (TCB, bp = 215°C), gives (1) in a high yield. The synthesis of (2)-(4) involves the decarbonylation of (1) with trimethylamine N …

Recognition of Viologen Derivatives in Water by N-Alkyl Ammonium Resorcinarene Chlorides

2017

Three water-soluble N-alkyl ammonium resorcinarene chlorides decorated with terminal hydroxyl groups at the lower rims were synthesized and characterized. The receptors were decorated at the upper rim with either terminal hydroxyl, rigid cyclohexyl, or flexible benzyl groups. The binding affinities of these receptors toward three viologen derivatives, two of which possess an acetylmethyl group attached to one of the pyridine nitrogens, in water were investigated via 1H NMR spectroscopy, fluorescence spectroscopy, and isothermal titration calorimetry (ITC). ITC quantification of the binding process gave association constants of up to 103 M–1. Analyses reveal a spontaneous binding process whi…