Van der Waals Forces and Shielding Effects

... 978-3-642-66176-1 DOI: 10.1007/978-3-642-66,176-1 Library of Congress
Cataloging in Publication Data: Rummens, Frans H A 1933 – Van der Waals
forces in NMR intermolecular shielding effects. (NMR basic principles and
progress; v.

Van der Waals Forces and Shielding Effects

Author: Frans H.A. Rummens

Publisher: Springer Science & Business Media

ISBN: 3642661769

Page: 122

View: 155

The usefulness of solvent effect studies on NMR chemical shifts need not be elabo rated here; many applications of solvent effects continue to be published in great profusion. Quite a few intermolecular phenomenae may contribute to solvent shifts, but there is always the ubiquitous Van der Waals effect ow. Contrary to such other effects as neighbour anisotropy 0a, reaction field contribution 0E or complexation effects 0e, no major direct use has yet been found for the Van der Waals effect. So far the role of the Van der Waals effect has been that of a nasty, disturbing phenom enon, something to be eliminated at all costs. But it is precisely in this latter respect where almost all solvent effect studies fall short. Not only is Ow usually large (larger than 0a and 0E even in 1 H NMR and probably the dominating term with heavier nuclei), but it is strongly variable from one solute to another and even from one nu clear site to another in the same solute molecule. No referencing technique, however cleverly devised, will be capable of eliminating the Ow contribution from the other, presumedly more interesting contributions. It appeared quite recently that mathematical trickery by the name of "factor analysis" could achieve the sought-for separation of contribuants.

Microbial Adhesion to Surfaces

( i ) Long - range attractive interactions These result from the van der Waals and
electrostatic forces . ... Wim and , since the liquid has a partial shielding effect on
the interaction force , the van der Waals force Fvdw is reduced by the ratio Wim lū
.

Microbial Adhesion to Surfaces

Author: R. C. W. Berkeley

Publisher:

ISBN:

Page: 559

View: 410

Subject guide to German books in print

Aulis / Deubner ' Kt 13 , 80 ( 3 - 7614 - 0150 - 7 ) ( CH - BB ] Das
Wissenschaftliche Werk von Hermann Staudinger . Gesammelte Arbeiten nach ...
00 ) ( 3 - 540 - 067426 ) Van der Waals Forces and Shielding Effects . 1975 . 13
figs 46 tab .

Subject guide to German books in print

Author:

Publisher:

ISBN:

Page:

View: 214

Australian Journal of Chemistry

Abstract A novel van der Waals shielding mechanism is discussed which
contributes to the magnetic shielding non - equivalence of optical ... 9 Rummens ,
F . H . A . , ' Van der Waals Forces and Shielding Effects ' ( Springer : Berlin 1975
) .

Australian Journal of Chemistry

Author:

Publisher:

ISBN:

Page:

View: 989

Spectroscopic Properties of Inorganic and Organometallic Compounds

The series ' N.M.R. , Basic Principles and Progress ' has proved to be prolific with
books on ' Van der Waals Forces and Shielding Effects ' , by F. H. A. Rummens , ' '
High Resolution N.M.R. Spectroscopy in Solids ' , by M. Mehring , ' Chlorine ...

Spectroscopic Properties of Inorganic and Organometallic Compounds

Author:

Publisher: Royal Society of Chemistry

ISBN:

Page: 504

View: 537

Reflecting the growing volume of published work in this field, researchers will find this book an invaluable source of information on current methods and applications.

NMR Spectroscopy and Polymer Microstructure

Li and Chestnut ( 1985 ) have presented evidence that correlate shielding y -
effects with attractive van der Waals forces and not repulsive steric interactions ,
though their results still suggest that the gauche arrangement of the observed ...

NMR Spectroscopy and Polymer Microstructure

Author: Alan E. Tonelli

Publisher: Wiley-VCH

ISBN:

Page: 252

View: 347

Describes both high resolution solution and solid state techniques; presents applications to synthetic and biological polymers; demonstrates the connection between microstructures, conformations, and NMR spectra of polymers. Annotation copyrighted by Book News, Inc., Portland, OR

Applied Mechanics Reviews

... mathematically sharp crack under symmetric van der Waals ' forces at large
separations has them decaying ( Mode 1 ) ... a derivation does not properly
account for interaction v = 0 , Txy = 0 , for x > 0 ( 2.13 ) and shielding effects , but
suffices ...

Applied Mechanics Reviews

Author:

Publisher:

ISBN:

Page:

View: 523

Blasting Vibrations and Their Effects on Structures

The diamagnetic anisotropy effect da and in specific instances de give a positive
or upfield shift . ... due to the solvent magnetic anisotropy ; ow — the shift due to
van der Waals interaction between solvent and solute molecules ; 08 - the
reaction - field effect or the shift due to polar effects ... As pointed out earlier , six
factors are postulated as contributing to the shielding effect on a particular
sample proton .

Blasting Vibrations and Their Effects on Structures

Author: Harry R. Nicholls

Publisher:

ISBN:

Page: 105

View: 707

Chemistry and Industry

He describes in detail the determination of anharmonic force constants for
triatomic molecules and indicates their ... TI Williams N.m.r. basic principles and
progress volume 10 ( van der Waals forces and shielding effects ) 1975 editors P
Diehl ...

Chemistry and Industry

Author:

Publisher:

ISBN:

Page:

View: 144

Journal of Solution Chemistry

Chemical shift of xenon in mixtures of water and acetonitrile and water and p -
dioxane vs . molar composition . ACKNOWLEDGMENT Some of ... F . H . A .
Rummens , in Van der Waals Forces and Shielding Effects . NMR Basic
Principles and ...

Journal of Solution Chemistry

Author:

Publisher:

ISBN:

Page:

View: 850

Optical Pumping and Xenon NMR

[ 135 ] F. H. A. Rummens , in van der Waals Forces and Shielding Effects , NMR
Basic Principles and Progress Vol . 10 ( Springer - Verlag , New York , 1975 ) . [
136 ] T. R. Stengle , S. M. Hosseini , H. G. Basiri and K. L. Williamson , J. Sol .

Optical Pumping and Xenon NMR

Author: M. Daniel Raftery

Publisher:

ISBN:

Page: 374

View: 696