ChemInform Abstract: LASER FLUORESCENCE STUDIES OF CARBONYL AND CARBOXYLIC ACID OXYGEN ATOM ABSTRACTION REACTIONS BY GROUP 3B ATOMS

1979 ◽  
Vol 10 (32) ◽  
Author(s):  
K. LIU ◽  
J. M. PARSON
Keyword(s):  
Carboxylic Acid ◽  
Oxygen Atom ◽  
Laser Fluorescence ◽  
Fluorescence Studies

Laser fluorescence studies of HF rotational relaxation

1977 ◽  
Vol 24 (2) ◽  
pp. 219-226 ◽  
Author(s):  
N.C. Lang ◽  
J.C. Polanyi ◽  
J. Wanner
Keyword(s):  
Laser Fluorescence ◽  
Rotational Relaxation ◽  
Fluorescence Studies

Laser fluorescence studies of molecular iodine

1978 ◽  
Vol 35 (3) ◽  
pp. 617-637 ◽  
Author(s):  
R. Clark ◽  
A.J. McCaffery
Keyword(s):  
Molecular Iodine ◽  
Laser Fluorescence ◽  
Fluorescence Studies

Catalytic transformation of alcohols to carboxylic acid salts and H2 using water as the oxygen atom source

2013 ◽  
Vol 5 (2) ◽  
pp. 122-125 ◽  
Author(s):  
Ekambaram Balaraman ◽  
Eugene Khaskin ◽  
Gregory Leitus ◽  
David Milstein
Keyword(s):  
Carboxylic Acid ◽  
Oxygen Atom ◽  
Catalytic Transformation ◽  
Atom Source ◽  
Acid Salts

scholarly journals Ethyl 1H-indole-2-carboxylate

IUCrData ◽  
2020 ◽  
Vol 5 (9) ◽  
Author(s):  
Will E. Lynch ◽  
Christine R. Whitlock ◽  
Clifford W. Padgett
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Oxygen Atom ◽  
Thionyl Chloride ◽  
Molecular Packing ◽  
Axis Direction ◽  
Indole Compounds ◽  
Hydrogen Bonded

Our work in the area of synthesis of tris indole compounds as a potential chelator led to the synthesis and crystallization of ethyl 1H-indole-2-carboxylate, C11H11NO2, an indole that was synthesized by the thionyl chloride reaction of 1H-indole-2-carboxylic acid, followed by dissolution in ethanol. The molecular packing exhibits a herringbone pattern with the zigzag running along the b-axis direction; the compound crystallizes as a hydrogen-bonded dimer resulting from O...H—N hydrogen bonds, between the indole N—H group and the keto oxygen atom, which build centrosymmetric R 2 2(10) ring motifs in the crystal.

scholarly journals An adenosine triphosphate-dependent carbamoylphosphate-3-hydroxymethylcephem O-carbamoyltransferase from Streptomyces clavuligerus

1980 ◽  
Vol 185 (3) ◽  
pp. 555-564 ◽  
Author(s):  
S J Brewer ◽  
P M Taylor ◽  
M K Turner
Keyword(s):  
Carboxylic Acid ◽  
Oxygen Atom ◽  
Deae Cellulose ◽  
Streptomyces Clavuligerus ◽  
Wide Range ◽  
Nucleoside Triphosphates ◽  
Phosphate Anions ◽  
Beta 2 ◽  
Methylene Group ◽  
Carbamoyl Group

Cell-free supernatants from cells of Streptomyces clavuligerus (N.R.R.L. 3585), which are actively synthesizing cephamycin C, transfer a carbamoyl group from carbamoylphosphate to a 3-hydroxymethylceph-3-em-4-carboxylic acid nucleus to form a 3-carbamoyloxymethylcephem. This reaction was stimulated by nucleoside triphosphates and by a mixture of Mn2+ and Mg2+ cations. The enzyme responsible was purified 40-fold by batch absorption onto DEAE-cellulose and hydroxyapatite. The purified O-carbamoyltransferase is most active at pH 6.8. It is stabilized by phosphate anions, but is inhibited by PPi anions, (NH4)2SO4 or NaCl. The enzyme is stimulated by ATP, but it is not known whether this nucleotide acts as an effector or as a substrate. Some activity is observed with dATP, but two other analogues of ATP, in which a methylene group replaced the oxygen atom between the alpha- and beta- or the beta- and gamma-phosphorus atoms, inhibit the action of ATP itself. The enzyme synthesizes a wide range of 3-carbamoyloxymethylcephems. The structure of some of these products, for example that of cefuroxime (3-carbamoyloxymethyl-7 beta-[2-(fur-2-yl)-2-syn-methoxyiminoacetamido]ceph-3-em-4-carboxylic acid), was confirmed by their proton-n.m.r. spectra.

13C N.M.R. and Single-Crystal X-Ray Structural Investigation of the Fluoroquinolone Antimicrobial Drug Norfloxacin 2DCl.D2O

1994 ◽  
Vol 47 (5) ◽  
pp. 799 ◽  
Author(s):  
SC Wallis ◽  
LR Gahan ◽  
BG Charles ◽  
TW Hambley
Keyword(s):  
Crystal Structure ◽  
Structural Analysis ◽  
Carboxylic Acid ◽  
Carbon Atom ◽  
Oxygen Atom ◽  
Single Crystal ◽  
Structural Investigation ◽  
Monoclinic Space Group ◽  
Piperazine Ring ◽  
X Ray

The sites of deuteronation of the molecule norfloxacin.2DCl.D2O have been investigated by 13C n.m.r. and a single-crystal structure determination. The 13C n.m.r. spectrum of norfloxacin (3 M DCl ) displays 14 lines, seven of which display 19F-13C coupling. The observation of 19F-13C coupling for the resonance at 171.0 ppm (J 3.9 Hz) allows positive assignment of this resonance to the keto carbon atom. The position of this resonance was found to be sensitive to [D+]. The crystals of norfloxacin.2DCl.D2O are monoclinic, space group P21/c, with a 8.536(2), b 14.379(3), c 14.985(4) Ǻ, β 93.40(2)°, V 1836.0(7) Ǻ3, and Z = 4. The structure was refined to R 0.039 and Rw 0.041. The n.m.r. study, combined with the structural analysis permits assignment of the sites of deuteronation for this molecule as an oxygen of the carboxylic acid, the external nitrogen of the piperazine ring and the keto oxygen atom.

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