DielsAlderCyclization of a Dihydropyridine: NMR Spectroscopy, X-Ray Crystallography, and DFT Computations. Bent Aromatic Dimeric Clusters in the Solid Phase

2014 ◽  
Vol 97 (10) ◽  
pp. 1365-1382
Author(s):  
Gideon Fraenkel ◽  
Jinhua Song ◽  
Albert Chow ◽  
Judith C. Gallucci
Keyword(s):  
Nmr Spectroscopy ◽  
Solid Phase ◽  
X Ray ◽  
Dft Computations ◽  
X Ray Crystallography

[Zn(phen)2(CX3COO)]+, X = H orCl; Influence of X on the Coordination Mode of the Carboxylate Group (phen = 1,10-Phenanthroline)

2005 ◽  
Vol 60 (10) ◽  
pp. 1049-1053 ◽  
Author(s):  
Zeanab Talaei ◽  
Ali Morsali ◽  
Ali R. Mahjoub
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Coordination Mode ◽  
Bidentate Ligand ◽  
Carboxylate Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Coordinate Geometry ◽  
C Nmr

Two new ZnII(phen)2 complexes with trichloroacetate and acetate anions, [Zn(phen)2(CCl3COO)- (H2O)](ClO4) and [Zn(phen)2(CH3COO)](ClO4), have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopy. The single crystal X-ray data of these compounds show the Zn atoms to have six-coordinate geometry. From IR spectra and X-ray crystallography it is established that the coordination of the COO− group is different for trichloroacetate and acetate. The former acts as a monodentate whereas the latter acts as a bidentate ligand.

Structures of Nonheme Oxoiron(IV) Complexes from X-ray Crystallography, NMR Spectroscopy, and DFT Calculations

2005 ◽  
Vol 44 (24) ◽  
pp. 3690-3694 ◽  
Author(s):  
Eric J. Klinker ◽  
József Kaizer ◽  
William W. Brennessel ◽  
Nathaniel L. Woodrum ◽  
Christopher J. Cramer ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
X Ray ◽  
X Ray Crystallography

A Solid-State NMR Approach to Structure Determination of Membrane-Associated Peptides and Proteins

1997 ◽  
Author(s):  
S.J. Opella ◽  
L.E. Chirlian
Keyword(s):  
Nmr Spectroscopy ◽  
Membrane Proteins ◽  
Structural Biology ◽  
Experimental Studies ◽  
Globular Proteins ◽  
Biological Properties ◽  
Cellular Functions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Form And Function

Structural biology relies on detailed descriptions of the three-dimensional structures of peptides, proteins, and other biopolymers to explain the form and function of biological systems ranging in complexity from individual molecules to entire organisms. NMR spectroscopy and X-ray crystallography, in combination with several types of calculations, provide the required structural information. In recent years, the structures of several hundred proteins have been determined by one or both of these experimental methods. However, since the protein molecules must either reorient rapidly in samples for multidimensional solution NMR spectroscopy or form high quality single crystals in samples for X-ray crystallography, nearly all of the structures determined up to now have been of the soluble, globular proteins that are found in the cytoplasm and periplasmof cells and fortuitously have these favorable properties. Since only a minority of biological properties are expressed by globular proteins, and proteins, in general, have evolved in order to express specific functions rather than act as samples for experimental studies, there are other classes of proteins whose structures are currently unknown but are of keen interest in structural biology. More than half of all proteins appear to be associated with membranes, and many cellular functions are expressed by proteins in other types of supramolecular complexes with nucleic acids, carbohydrates, or other proteins. The interest in the structures of membrane proteins, structural proteins, and proteins in complexes provides many opportunities for the further development and application of NMR spectroscopy. Our understanding of polypeptides associated with lipids in membranes, in particular, is primitive, especially compared to that for globular proteins. This is largely a consequence of the experimental difficulties encountered in their study by conventional NMR and X-ray approaches. Fortunately, the principal features of two major classes of membrane proteins have been identified from studies of several tractable examples. Bacteriorhodopsin (Henderson et al., 1990), the subunits of the photosynthetic reaction center (Deisenhofer et al., 1985), and filamentous bacteriophage coat proteins (Shon et al., 1991; McDonnell et al., 1993) have all been shown to have long transmembrane hydrophobic helices, shorter amphipathic bridging helices in the plane of the bilayers, both structured and mobile loops connecting the helices, and mobile N- and C-terminal regions.

scholarly journals Mono- and dimeric zinc(ii) complexes for PLA production and degradation into methyl lactate – a chemical recycling method

2020 ◽  
Vol 11 (13) ◽  
pp. 2381-2389 ◽  
Author(s):  
Jack Payne ◽  
Paul McKeown ◽  
Mary F. Mahon ◽  
Emma A. C. Emanuelsson ◽  
Matthew D. Jones
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Recycling ◽  
Methyl Lactate ◽  
X Ray ◽  
X Ray Crystallography

A series of well-defined mono- and dimeric Zn(ii)-complexes were prepared and fully characterised by X-ray crystallography and NMR spectroscopy.

scholarly journals 2-(3,5-Dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine

Molbank ◽  
10.3390/m1077 ◽  
2019 ◽  
Vol 2019 (3) ◽  
pp. M1077
Author(s):  
Lan ◽  
Zheng ◽  
Wang
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
1H Nmr ◽  
Structure Determination ◽  
1H Nmr Spectroscopy ◽  
Pyrazole Ring ◽  
Hydrogen Atoms ◽  
X Ray ◽  
X Ray Crystallography

The compound 2-(3,5-dimethyl-1H-pyrazol-1-yl)thiazolo[4,5-b]pyridine (1) was synthesized with a yield of 71% by the reaction of 1-(thiazolo[4,5-b]pyridine-2-yl)hydrazine and acetylacetone. The structure was characterized by a single-crystal X-ray structure determination as well as 1H and 13C{1H} NMR spectroscopy. X-ray crystallography on 1 confirms the molecule consists of a pyridine–thiazole moiety and the pyrazole ring, and all non-hydrogen atoms are planar.

Sign in / Sign up

Export Citation Format

Share Document