Download e-book for kindle: Contrast Agents I: Magnetic Resonance Imaging (Topics in by Werner Krause (Editor)

By Werner Krause (Editor)

ISBN-10: 3540422471

ISBN-13: 9783540422471

BLECK: magazine OF the yankee CHEMICAL SOCIETY "...offers a pleasant evaluate for starting graduate scholars and novices to the field."

Show description

Read or Download Contrast Agents I: Magnetic Resonance Imaging (Topics in Current Chemistry, 221) PDF

Similar chemistry books

Download e-book for iPad: Chemokine Receptors in Cancer by Chareeporn Akekawatchai, Marina Kochetkova, Jane Holland

Chemokine Receptors in melanoma summarizes the starting to be physique of facts that a number of chemokine receptors give a contribution to tumor habit. Chemokine receptors have been first pointed out on leukocytes and mediate directed migration of many host cells to websites of ligand expression. it's now good proven that the majority malignant cells additionally convey a number of chemokine receptor.

Chlorinated Paraffins by Heidelore Fiedler (auth.), Jacob Boer (eds.) PDF

Chlorinated paraffins are one of many final periods of chlorinated compounds which are nonetheless being produced all over the world and utilized in excessive amounts in lots of purposes. they're rather utilized in slicing oils within the steel undefined, but additionally as lubricants, plasticizers, flame retardants and as ingredients in adhesives, rubber, paints and sealants.

Additional info for Contrast Agents I: Magnetic Resonance Imaging (Topics in Current Chemistry, 221)

Example text

Two major isomeric species were observed for the (RRRR)-, (RRRS)- and [(RSRS)Eu(TCE-DOTA)]5– complexes in a relative ratio, M/m of 1:4, 2:1 and 4:1, respectively, compared with a M/m ratio of 4:1 for [Eu(DOTA)]–. For [(RRSS)-Eu(TCEDOTA)]5–, only one (M) isomer is present in solution. For the (RRRR)-Eu complex, the major (m) isomer (not present in the crystal) must adopt a L/(llll) configuration, while the minor (M) isomer possesses a L/(dddd) configuration. The absolute configuration of the stereogenic center at C is determining the lefthanded helicity of the complex, so that neither the D/(dddd) nor the D/(llll) complexes are present [79].

The EXSY spectra for the (RRRR)- and (RRRS)- complexes were much simpler, as no cross peaks were observed between corresponding axial proton resonances of the major and minor iso- Structures of MRI Contrast Agents in Solution 41 mers, indicating that concerted arm rotation was occurring two orders of magnitude more slowly than ring inversion. The introduction of only one chiral center in DOTA by derivatizing one acetate a-carbon with a para-nitrophenyl group (DOTA-pNB) [80] also results in four possible diastereomers upon chelation.

The isomerizarion process of [Yb(DOTMA)]–, like for [Yb(DOTA)]– [63], involves exchange of a water molecule in the capping position of the CSAP coordination polyhedron, as shown by the sign of isomerization entropy values obtained by 1H NMR [76]. Nearinfrared circular dichroism (NIR CD) spectral studies of [Yb(DOTMA)]– in solution provided an example of coupling chiroptical methods and paramagnetic NMR to study the absolute configuration of chiral lanthanide complexes [77]. The ligand tetracarboxyethyl DOTA derivative (TCE-DOTA) was synthesized as a mixture of the six stereoisomers defined by the absolute configuration of the four chiral carbons, RRRR/SSSS pair, RSSS/SRRR pair, RSRS and RRSS, which were separated, crystallized and their crystal structures determined [78, 79].

Download PDF sample

Contrast Agents I: Magnetic Resonance Imaging (Topics in Current Chemistry, 221) by Werner Krause (Editor)


by Kevin
4.4

Rated 4.83 of 5 – based on 39 votes