A nuclear magnetic resonance investigation of the micellar properties of a series of sodium cyclohexylalkanoates

1999 ◽  
Vol 77 (11) ◽  
pp. 1994-2000 ◽  
Author(s):  
Judith A MacInnis ◽  
R Palepu ◽  
D Gerrard Marangoni
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Conformational Changes ◽  
Chemical Shifts ◽  
Micelle Formation ◽  
Counterion Binding ◽  
Micellar Properties ◽  
Aggregation Numbers ◽  
Multinuclear Nmr Spectroscopy ◽  
Magnetic Resonance Investigation

The micellar properties of a family of surfactants, the sodium cyclohexylalkanoates, have been investigated in aqueous solution using multinuclear NMR spectroscopy. C-13 chemical shift measurements have been used to determine both the cmc values and the micellar aggregation numbers (Ns values) of these surfactants. The cmc values and the degrees of counterion binding were estimated from 23Na chemical shift measurements. The critical micelle concentrations (cmc's) and the aggregation numbers determined from the NMR experiments indicate that these amphiphiles have high cmc's and low aggregation numbers when compared to other single-headed surfactants (most notably the sodium alkanoates). The conformational changes incurred by the carbon atoms upon micelle formation have been deduced from the 13C chemical shift differences (δsurf,mic - δsurf,aq). These results are used to discuss the formation of the aggregates of the sodium cyclohexylalkanoate surfactants as a function of the length of the alkanoate side chain.Key words: micelles, surfactants, NMR spectroscopy, chemical shifts, aggregation numbers, degree of counterion binding, conformational changes.

scholarly journals Structure of Nanobody Nb23

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3567
Author(s):  
Mathias Percipalle ◽  
Yamanappa Hunashal ◽  
Jan Steyaert ◽  
Federico Fogolari ◽  
Gennaro Esposito
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Solution Structure ◽  
Chemical Shifts ◽  
Molecular Size ◽  
Side Chain ◽  
3D Nmr ◽  
Target Antigen ◽  
Internuclear Distances ◽  
2D And 3D

Background: Nanobodies, or VHHs, are derived from heavy chain-only antibodies (hcAbs) found in camelids. They overcome some of the inherent limitations of monoclonal antibodies (mAbs) and derivatives thereof, due to their smaller molecular size and higher stability, and thus present an alternative to mAbs for therapeutic use. Two nanobodies, Nb23 and Nb24, have been shown to similarly inhibit the self-aggregation of very amyloidogenic variants of β2-microglobulin. Here, the structure of Nb23 was modeled with the Chemical-Shift (CS)-Rosetta server using chemical shift assignments from nuclear magnetic resonance (NMR) spectroscopy experiments, and used as prior knowledge in PONDEROSA restrained modeling based on experimentally assessed internuclear distances. Further validation was comparatively obtained with the results of molecular dynamics trajectories calculated from the resulting best energy-minimized Nb23 conformers. Methods: 2D and 3D NMR spectroscopy experiments were carried out to determine the assignment of the backbone and side chain hydrogen, nitrogen and carbon resonances to extract chemical shifts and interproton separations for restrained modeling. Results: The solution structure of isolated Nb23 nanobody was determined. Conclusions: The structural analysis indicated that isolated Nb23 has a dynamic CDR3 loop distributed over different orientations with respect to Nb24, which could determine differences in target antigen affinity or complex lability.

Chemical shift correlated two-dimensional nmr spectroscopy and its application to solving the proton nmr spectra of oligoribonucleotides

1980 ◽  
Vol 58 (18) ◽  
pp. 1947-1956 ◽  
Author(s):  
Alex D. Bain ◽  
Russell A. Bell ◽  
Jeremy R. Everett ◽  
Donald W. Hughes
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Nmr Spectra ◽  
Pulse Sequence ◽  
Chemical Shifts ◽  
Proton Nmr ◽  
Two Dimensional

An alternative two-dimensional nmr pulse sequence, (90°–t1/2–90°–t1/2–FID),correlates the chemical shifts of coupled nuclei. The application of this technique to the solution of the complicated proton nmr spectra of oligoribonucleotides is discussed.

Synthese und Multikern-NMR-Spektroskopie einiger vier-und fünfgliedriger Zinn—Stickstoff-Heterocyclen / Synthesis and Multinuclear NMR Spectroscopy of Some Four-and Five-Membered Tin —Nitrogen Heterocycles

1988 ◽  
Vol 43 (6) ◽  
pp. 707-714 ◽  
Author(s):  
Carin Stader ◽  
Bernd Wrackmeyer ◽  
Dieter Schlosser
Keyword(s):  
Nmr Spectroscopy ◽  
Lone Electron Pair ◽  
Electron Pair ◽  
Chemical Shifts ◽  
Nitrogen Heterocycles ◽  
Spiro Compounds ◽  
Coupling Constants ◽  
Ring Size ◽  
Multinuclear Nmr Spectroscopy ◽  
Cyclic Compounds

Tin-nitrogen heterocycles [1,3,2,4λ2-diazasila- (1), -λ4-stannetidines (2), spiro-compounds (3, 4), 1,3,2λ4,4λ4-diazadistannetidines (5), 1,3,4,5,2λ2-diazadisila- (6) and -λ4-stannolidines (7)] have been characterized by 13C, 15N, 29Si and 119Sn NMR spectroscopy [chemical shifts δX and coupling constants nJ(119Sn-X) (n = 1, 2, 3; X = 13C, 15N, 29Si, 119Sn]. The influence of the ring size becomes apparent in particular by comparison of the various coupling constants. In the compounds 1 and 6 the presence of a two-coordinate tin atom is reflected by the extremely low shielding of the 119Sn nuclei and also by the reduced shielding of the 29Si nucleus. The comparison with δ(29Si) data for corresponding non-cyclic compounds indicates that the latter effect may be traced to intra-annular interactions in 1 and 6 which involve the lone electron pair at the tin atom.

9Be nuclear magnetic resonance spectroscopy trends in discrete complexes: an update

2020 ◽  
Vol 75 (5) ◽  
pp. 459-472 ◽  
Author(s):  
Jenna K. Buchanan ◽  
Paul G. Plieger
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Solution Nmr ◽  
Resonance Spectroscopy ◽  
Coordination Numbers ◽  
Solution Nmr Spectroscopy ◽  
Beryllium Complexes

Abstract9Be solution NMR spectroscopy is a useful tool for the characterisation of beryllium complexes. An updated comprehensive table of the 9Be NMR chemical shifts of beryllium complexes in solution is presented. The recent additions span a greater range of chemical shifts than those previously reported, and more overlap is observed between the chemical shift regions of four-coordinate complexes and those with lower coordination numbers. Four-coordinate beryllium species have smaller ω1/2 values than the two- and three-coordinate species due to their higher order symmetry. In contrast to previous studies, no clear relationship is observed between chemical shift and the size and number of chelate rings.

scholarly journals Use of 95Mo NMR Spectroscopy as a New Approach to Structural Analysis of Diamagnetic Molybdenum Complexes

1976 ◽  
Vol 31 (5) ◽  
pp. 454-456 ◽  
Author(s):  
O. Lutz ◽  
A. Nolle ◽  
P. Kroneck
Keyword(s):  
Fourier Transform ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Oxidation States ◽  
New Approach ◽  
Molybdenum Complexes ◽  
Experimental Parameters

Abstract Fourier Transform NMR measurements of 95Mo and 97Mo are reported for several molybdenum compounds in different oxidation states. Using the molybdate ion as a reference, chemical shifts from about +500 ppm to about -1900 ppm have been observed. Experimental parameters and a chemical shift scale are given.

A 139La NMR study of the interactions between the La(III) cation and D-ribose in aqueous solution

1994 ◽  
Vol 72 (7) ◽  
pp. 1753-1757 ◽  
Author(s):  
Zhigang Chen ◽  
Nicole Morel-Desrosiers ◽  
Jean-Pierre Morel ◽  
Christian Detellier
Keyword(s):  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Stability Constant ◽  
Chemical Shifts ◽  
Similar Treatment ◽  
Calorimetric Measurements ◽  
Nmr Study ◽  
The Stability ◽  
Good Agreement

The interactions of the La(III) cation with D-ribose and with D-arabinose in aqueous solution were investigated by 139La NMR spectroscopy. In the case of D-ribose, the formation of a La(III)-sugar complex was indicated by variations of the 139La chemical shift and linewidth with an increase of the sugar concentration in solution. In contrast, the complexation of La(III) by arabinose is very weak and almost undetectable by 139La NMR. On the basis of a 1:1 stoichiometry, the stability constant for the complex of La(III) with D-ribose was calculated from the observed 139La chemical shift values. A similar treatment was done for the viscosity corrected 139La linewidths using arabinose as an uninteractive reference. The stability constants, K, obtained independently from 139La chemical shifts and linewidths are in good agreement, 2.8 ± 0.5 and 2.2 ± 0.6 M−1 respectively at 299.0 ± 0.5 K. The thermodynamic parameters for the complexation of La(III) by D-ribose could also be obtained: ΔH0 = −12 ± 2 kJ mol−1, and ΔS0 = −31 ± 5 J K−1 mol−1. These values are in very good agreement with those obtained by calorimetric measurements.

NMR effective radius of hydrogen in XIV group hydrides evaluated by NMR spectroscopy

2017 ◽  
Vol 46 (41) ◽  
pp. 14094-14097 ◽  
Author(s):  
M. Benedetti ◽  
F. De Castro ◽  
A. Ciccarese ◽  
F. P. Fanizzi
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Shift ◽  
Chemical Shifts ◽  
Effective Radius ◽  
Nmr Chemical Shift ◽  
Ionic Radii ◽  
Nmr Chemical Shifts

In the [ABrnIm] (A = C, Si, Ge, Sn; n + m = 4) compounds, with the heavier halido ligands bonded to the central IV group elements, the 13C, 29Si, 73Ge and 119Sn NMR chemical shifts were found to be linearly related to the bonded halides ionic radii overall sum, ∑(rh). The 207Pb NMR chemical shift of the unstable [PbH4] hydride could be calculated.

Zinn(IV)-Verbindungen mit Ferrocenylchalkogenat- und Ferrocenylendichalkogenat-Liganden. Synthese und Multikern-NMR-Spektroskopie / Tin(IV) Compounds Containing Ferrocenyl Chalcogenate and Ferrocenylene Dichalcogenate Ligands. Synthesis and Multinuclear NMR Spectroscopy

1993 ◽  
Vol 48 (7) ◽  
pp. 940-950 ◽  
Author(s):  
Max Herberhold ◽  
Michaela Hübner ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Systematic Study ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spiro Compounds ◽  
Coupling Constants ◽  
Solution Nmr ◽  
Multinuclear Nmr Spectroscopy ◽  
Cp Mas Nmr ◽  
Sulfur Containing

A series of tin(IV) compounds containing ferrocenyl chalcogenate (FcE) and ferrocenylene dichalcogenate (fcE2) ligands (E = S, Se, Te) has been synthesized for a systematic study of the NMR spectra with particular emphasis on 13C, 119Sn, 77Se and 125Te NMR. All compounds are formally derived from tetramethylstannane, SnMe4, by stepwise replacement of methyl by either FcE or fcE2 ligands. Starting from lithioferrocene the products are tetrasubstituted stannanes Me4-nSn(EFc)n (n = 1 and 2, E = S, Se, Te; n = 3 and 4, E = S, Se). Starting from 1,1′dilithioferrocene, the products are 1,1′-disubstituted ferrocenes such as fc(E-SnMe3)2 (E = S, Se, Te), although 1,3-dichalcogena[3]ferrocenophane rings are formed whenever possible to give [3]ferrocenophanes fcE2SnMe2 (E = S, Se, Te) and fc[E-Sn(Me)E2fc]2 (E = S, Se) or tin spiro compounds Sn(E2fc)2 (E = S, Se, Te). Whereas all (8) possible sulfur-containing and all (8) selenium-containing products were accessible, some of the tellurium-rich compounds could not be isolated due to preferred formation of either Fc2Te2 or fcTe3.All compounds were characterized on the basis of their 1H, 13C, 119Sn and, if possible, 77Se and 125Te solution NMR spectra. In many cases, coupling constants such as 2J(119Sn1H), nJ(119Sn13C) (n = 1,2,3), 1J(119Sn77Se) and 1J(125Τe119Sn), 1J(77Se13C) and 1J(125Te13C) could be determined. The δ119Sn chemical shifts of analogous phenyl and ferrocenyl compounds, Me4-nSn(EPh) and Me4-nSn(EFc)n (n = 0-4, E = S, Se, Te), are discussed, and for a microcrystalline sample of tetrakis(ferrocenylselenolato)stannane, Sn(SeFc)4, the 119Sn and 77Se CP/MAS NMR spectra are reported and compared with the solution spectra.

Article

1998 ◽  
Vol 76 (9) ◽  
pp. 1266-1273 ◽  
Author(s):  
Gregory D Boucher ◽  
Aaron C MacDonald ◽  
Brent E Hawrylak ◽  
D Gerrard Marangoni
Keyword(s):  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Maleic Anhydride ◽  
Chain Length ◽  
Chemical Shifts ◽  
Sodium Bisulfite ◽  
Critical Micelle Concentrations ◽  
Aggregation Numbers ◽  
Nmr Techniques ◽  
Surfactant Systems

A family of two-headed surfactants, the disodium 4-alkyl-3-sulfonatosuccinates, has been synthesized by the monoesterification of maleic anhydride and the addition of sodium bisulfite to the corresponding monoester. The properties the micelles formed by these compounds in aqueous solution, and the conformations of the chains comprising the micellar interior, have been investigated using a combination of 1-D nmr experiments and homonuclear and heteronuclear 2-D nmr techniques. The critical micelle concentrations (cmc's) and the aggregation numbers determined from the nmr experiments indicate that, in agreement with the earlier literature on other two-headed surfactant systems, these amphiphiles have high cmc's and low aggregation numbers when compared to single-headed surfactants of comparable chain length. All these results are interpreted in terms of the effect of adding a second headgroup to a single-headed, single-tailed surfactant.Key words: micelles, surfactants, nmr spectroscopy, chemical shifts, aggregation numbers.

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