Search results for "Molecular chemistry"
showing 10 items of 1103 documents
(+)-(E)-Chrysanthenyl Acetate: A Molecule with Interesting Biological Properties Contained in the Anthemis secundiramea (Asteraceae) Flowers
2020
Anthemis secundiramea is a perennial herb native widespread throughout the Mediterranean basin. The oil obtained from the flowers of this plant has antimicrobial properties against gram-positive and -negative bacteria, and inhibits the biofilm formation. The extract of A. secundiramea also has antioxidant activity&mdash
Host-Guest Complexes of C-Ethyl-2-methylresorcinarene and Aromatic
2017
Abstract The C‐ethyl‐2‐methylresorcinarene (1) forms 1:1 in‐cavity complexes with aromatic N,N′‐dioxides, only if each of the aromatic rings has an N−O group. The structurally different C‐shaped 2,2′‐bipyridine N,N′‐dioxide (2,2′‐BiPyNO) and the linear rod‐shaped 4,4′‐bipyridine N,N′‐dioxide (4,4′‐BiPyNO) both form 1:1 in‐cavity complexes with the host resorcinarene in C 4v crown and C 2v conformations, respectively. In the solid state, the host–guest interactions between the 1,3‐bis(4‐pyridyl)propane N,N′‐dioxide (BiPyPNO) and the host 1 stabilize the unfavorable anti‐gauche conformation. Contrary to the N,N′‐dioxide guests, the mono‐N‐oxide guest, 4‐phenylpyridine N‐oxide (4PhPyNO), does …
Increased conformational rigidity of humic substances by oxidative biomimetic catalysis
2005
A synthetic water-soluble meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of iron(III) chloride, Fe(TDCPPS)Cl, was employed as a biomimetic catalyst in the oxidative coupling of terrestrial humic materials. High-performance size-exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance (CPMAS-(13)C NMR), electron paramagnetic resonance (EPR), and diffuse reflectance infrared spectroscopy (DRIFT) were used to follow conformational and structural changes brought about in different humic materials by the oxidative coupling. Increase in apparent weight-average molecular weight (Mw(a)) occurred invariably for all humic substances with the oxidative polymerization catalyzed …
Copper( ii ) complexes with phosphorylated 1,10-phenanthrolines: from molecules to infinite supramolecular arrays
2016
International audience; The reaction of phosphorylated 1,10-phenanthrolines 3-Pphen, 3,8-Pphen and 4,7-Pphen (3-Pphen = 3-diethoxyphosphorylphenanthroline, 3,8-Pphen = 3,8-bis(diethoxyphosphoryl) phenanthroline, 4,7-Pphen = 4,7-bis(diethoxyphosphoryl) phenanthroline) and hydrated copper(II) nitrate in a 1 : 1 ratio leads to the formation of supramolecular architectures. In the 1D coordination polymer [Cu(3-Pphen)(NO3)(2)](n) (2) the copper atom is coordinated to only one phenanthroline ligand and the coordination sphere is completed by two oxygen atoms of nitrate anions and the oxygen atom of the phosphoryl group from the neighbouring phenanthroline ligand. Complex Cu(3,8-Pphen)(NO3)(2) (3)…
Gallium(III) and Indium(III) Complexes with meso-Monophosphorylated Porphyrins: Synthesis and Structure. A First Example of Dimers Formed by the Self…
2017
International audience; The synthesis and structural characterization, both in solution by means of H-1 and P-31 NMR and UV-vis spectroscopies and in the solid state by X-ray diffraction on single crystal, of a series of gallium(III) and indium(III) meso-mono(diethoxyphosphoryl)porphyrins bearing different peripheral substituents as well as the corresponding monoesters and phosphonic acids are reported. This work describes the first example of the X-ray structure of a self-assembled dimer formed via strong binding between the oxygen atom of the phosphonate substituent and the gallium(III) cations of adjacent porphyrin molecules [Ga-O = 1.9708(13) angstrom].
Reactivity of bis(cyclohexylammonium) 4-nitrophenylphosphate with SnMe3 Cl. X-ray structure of 4-NO2 C6 H4 PO4(SnMe3)2·H2 O
2014
The reaction of bis(cyclohexylammonium) 4-nitrophenylphosphate with Me3 SnCl (1:2) under reflux in ethanol yielded the title compound 4-NO2 C6 H4 PO4(SnMe3)2H2 O (1). The X-ray crystallographic analysis achieved on single crystals obtained by slow evaporation at room temperature revealed the formation of an unexpected supramolecular coordination network. The elementary building block can be viewed as two Me3 Sn moieties linked by a bridging 4-nitrophenylphosphate ligand. The two tin atoms are five-coordinated and describe a trans-Me3 SnO2 geometry in a trigonal bipyramidal arrangement. However, the Sn atoms are distinct, exhibiting two different environments. Thus, one is linked to two axia…
The subtle balance of weak supramolecular interactions: The hierarchy of halogen and hydrogen bonds in haloanilinium and halopyridinium salts
2010
The series of haloanilinium and halopyridinium salts: 4-IPhNH₃Cl (1), 4-IPhNH₃Br (5), 4-IPhNH₃H₂PO₄ (6), 4-ClPhNH₃H₂PO₄ (8), 3-IPyBnCl (9), 3-IPyHCl (10) and 3-IPyH-5NIPA (3-iodopyridinium 5-nitroisophthalate, 13), where hydrogen or/and halogen bonding represents the most relevant non-covalent interactions, has been prepared and characterized by single crystal X-ray diffraction. This series was further complemented by extracting some relevant crystal structures: 4-BrPhNH3Cl (2, CCDC ref. code TAWRAL), 4-ClPhNH3Cl (3, CURGOL), 4-FPhNH3Cl (4, ANLCLA), 4-BrPhNH3H2PO4, (7, UGISEI), 3-BrPyHCl, (11, CIHBAX) and 3-ClPyHCl, (12, VOQMUJ) from Cambridge Structural Database for sake of comparison. Bas…
Crystal structure of (E)-N-(3,4-dimethoxybenzylidene)morpholin-4-amine
2014
In the title compound, C13H18N2O3, the benzene ring makes a dihedral angle of 17.19 (11)° with the least-squares plane formed by the four C atoms of the morpholine ring, which adopts a chair conformation. In the crystal, C—H...N hydrogen bonds link the molecules into supramolecular chains running along a 21screw axis parallel to theb-axis direction. Weak C—H...π interactions are also observed.
Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-N′-(3-hydroxy-4-methoxybenzylidene)nicotinohydrazide monohydrate
2019
The title Schiff base compound displays an E configuration with respect to the C=N double bond. The pyridine and benzene rings subtend a dihedral angle of 29.63 (7)°. In the crystal, the molecules are linked by N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N hydrogen-bonding interactions.
Stabilisation of Exotic Tribromide (Br3−) Anions via Supramolecular Interaction with A Tosylated Macrocyclic Pyridinophane. A Serendipitous Case.
2020
Tetraaza-macrocyclic pyridinophane L-Ts, decorated with a p-toluenesulfonyl (tosyl