Search results for "Spectral data"
showing 10 items of 56 documents
Protonation of 3-aminopyrroles
1987
Abstract The protonation of 3-aminopyrroles has been investigated using H and 13C n.m.r. spectroscopy. The spectral data are compatible with predominant protonation of the amino group with no evidence for protonation of the pyrrole ring.
ChemInform Abstract: Synthesis and Characterization of the Acetazolamide Complexes of Co(II) and Zn(II).
1987
Abstract The preparation and characterization of the complexes of Acetazolamide (Acm) with Co(II) and Zn(II) are described. The complexes are of the type M(Acm) 2 (NH 3 ) 2 . Monodentate or bidentate behaviour of Acm from the electronic properties and the IR spectral data is discussed. The probable structures of the complexes are proposed.
Flavonoids in Subtribe Centaureinae (Cass.) Dumort. (Tribe Cardueae, Asteraceae): Distribution and 13C-NMR Spectral Data
2012
Abstract This review reports the occurrence of flavonoids in subtribe Centaureinae of Asteraceae family. It extensively covers the literature up to 2010 and collects all available (13)C-NMR data.
Detection of Invisible Damages in ‘Rojo Brillante’ Persimmon Fruit at Different Stages Using Hyperspectral Imaging and Chemometrics
2021
[EN] The main cause of flesh browning in 'Rojo Brillante' persimmon fruit is mechanical damage caused during harvesting and packing. Innovation and research on nondestructive techniques to detect this phenomenon in the packing lines are necessary because this type of alteration is often only seen when the final consumer peels the fruit. In this work, we have studied the application of hyperspectral imaging in the range of 450-1040 nm to detect mechanical damage without any external symptoms. The fruit was damaged in a controlled manner. Later, images were acquired before and at 0, 1, 2 and 3 days after damage induction. First, the spectral data captured from the images were analysed through…
SPECTRAL GEOMETRY OF SPACETIME
2000
Spacetime, understood as a globally hyperbolic manifold, may be characterized by spectral data using a 3+1 splitting into space and time, a description of space by spectral triples and by employing causal relationships, as proposed earlier. Here, it is proposed to use the Hadamard condition of quantum field theory as a smoothness principle.
Antimony-121 mössbauer and infrared spectral study on halophenylantimonate(III) Compounds
1981
Abstract The synthesis and the 121 Sb Mossbauer and infrared spectra of halophenylantimonates(III) M[PhSbX 3 ] (M Me 4 N, Ph 4 As;X Cl, Br, I) are reported, and the spectral data are discussed and compared with those of SbX 4 and other related systems. The results are in accord with the participation of the antimony 5s electrons in the SbPh bond. In the interpretation of the electric field gradient, the contributions to V zz from both the lone pair and the SbPh bond electron densities are assumed to be dominant.
Copper(II) Complexes with Derivatives of Barbiturate
1984
Abstract NaCuL2(OH).1,5H2O, KCuP2(OH).1H2O, Na2CuL4 and K2CuP4-8H2O (HL=Phenobarbitone and HP=Methyl Phenobarbitone) were prepared and characterized by elemental analysis, IR and electronic spectral data and magnetic susceptibility measurements. The ESR spectra show and octahedral environment for the Cu(II) ion.
Lactones. Part 15: Synthesis of chiral spirolactones with a carane system—insect feeding deterrents
2002
Abstract Starting from (+)-3-carene 1 several spirolactones with carane backbone were synthesized. δ-Hydroxy-γ-lactone 5 was obtained by acidic lactonization of a γ,δ-epoxy ester. Iodolactone 8 and bromolactone 9 were products of iodolactonization of γ,δ-unsaturated acid 7 and bromolactonization of γ,δ-unsaturated ester 3 respectively. The halo lactones were subjected to reductive dehalogenation with tributyltin hydride and dehydrohalogenation with DBU. The structures of the lactones obtained were confirmed by X-ray analysis and spectral data.
ChemInform Abstract: Vinylogous and Coupled Hexahydroquinolinones and Dihydropyridines with Calcium-Modulating Effects.
1990
The vinylogous, anellated and non-anellated dihydropyridines 4 and their coupled analogues 5 are accessible through Hantzsch-type cyclization reactions. IR, 1H-NMR, and mass spectral data are in agreement with the postulated structures. Pharmacological investigations on electrically-stimulated left atria of guinea pigs with some of the compounds gave rise to positive inotropic activities whereas BaCl2-induced contractions of the ileum were inhibited in a dose-dependent manner by some of the products.
Systematic study of the physicochemical properties of a homologous series of aminobisphosphonates
2012
ABSTRACT: Aminobisphosphonates, e.g., alendronate and neridronate, are a well known class of molecules used as drugs for various bone diseases. Although these molecules have been available for decades, a detailed understanding of their most important physicochemical properties under comparable conditions is lacking. In this study, ten aminobisphosphonates, H2N(CH2)nC(OH)[P(O)(OH)2]2, in which n = 2-5, 7-11 and 15 have been synthesized. Their aqueous solubility as a function of temperature and pH, pKa-values, thermal stability, IR absorptions, and NMR spectral data for both liquid (1H, 13C, 31P-NMR) and solid state (13C, 15N and 31P-CPMAS NMR) were determined. Peer reviewed