New Structural Information on a Humic Acid from Two-Dimensional1H-13C Correlation Solid-State Nuclear Magnetic Resonance

2001 ◽  
Vol 35 (10) ◽  
pp. 1928-1934 ◽  
Author(s):  
J.-D. Mao ◽  
B. Xing ◽  
K. Schmidt-Rohr
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Humic Acid ◽  
Solid State ◽  
Magnetic Resonance ◽  
Structural Information ◽  
Nuclear Magnetic

Analysis of Lead Carboxylates and Lead-Containing Pigments in Oil Paintings by Solid- State Nuclear Magnetic Resonance

2014 ◽  
Vol 1656 ◽  
pp. 149-156 ◽  
Author(s):  
Jaclyn Catalano ◽  
Yao Yao ◽  
Anna Murphy ◽  
Nicholas Zumbulyadis ◽  
Silvia A. Centeno ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
Structural Information ◽  
Chemical Shifts ◽  
Paint Film ◽  
Type I ◽  
Oil Paintings ◽  
Lead Stearate ◽  
Nuclear Magnetic

ABSTRACTSoap formation in traditional oil paintings occurs when heavy-metal-containing pigments, such as lead white, 2Pb(CO3)2·Pb(OH)2, and lead-tin yellow type I, Pb2SnO4, react with fatty acids in the binding medium. These soaps may form aggregates that can be 100-200 μm in diameter, which swell and protrude through the paint surface, resulting in the degradation of the paint film and damage to the integrity of the artwork. In addition, soap formation has been reported to play a role in the increased transparency of paint films that allows the painting support, the preparatory drawing, and the artists’ alterations to become visible to the naked eye. The factors that trigger soap formation and the mechanism(s) of the process are not yet well understood. To elucidate these issues, chemical and structural information is necessary which can be obtained by solid-state 207Pb, 119Sn, and 13C nuclear magnetic resonance (NMR). In the present study, a combination of 207Pb NMR pulse sequences was used to determine accurately the NMR parameters of lead-containing pigments and lead carboxylates known to be involved in soap formation, such as lead palmitate, lead stearate, and lead azelate. These results show that the local coordination environment of lead azelate is different from lead palmitate or lead stearate and therefore it is unlikely that lead azelate would be incorporated into an ordered structure containing lead palmitate and lead stearate. In addition, the chemical shifts of the pigments obtained are different from those of the soaps, demonstrating that 207Pb NMR is useful in characterizing the components when present in a mixture, such as a paint film. The NMR methods discussed can also be applied to other Pb-containing cultural heritage materials, electronic and optoelectronic materials, superconducting materials, and environmentally contaminated materials.

scholarly journals Recent developments in solid–state magic–angle spinning, nuclear magnetic resonance of fully and significantly isotopically labelled peptides and proteins

2004 ◽  
Vol 359 (1446) ◽  
pp. 997-1008 ◽  
Author(s):  
Suzana K. Straus
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
Solid State Nmr ◽  
Structural Information ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Recent Developments ◽  
Angle Spinning ◽  
Nuclear Magnetic

In recent years, a large number of solid–state nuclear magnetic resonance (NMR) techniques have been developed and applied to the study of fully or significantly isotopically labelled ( 13 C, 15 N or 13 C/ 15 N) biomolecules. In the past few years, the first structures of 13 C/ 15 N–labelled peptides, Gly–Ile and Met–Leu–Phe, and a protein, Src–homology 3 domain, were solved using magic–angle spinning NMR, without recourse to any structural information obtained from other methods. This progress has been made possible by the development of NMR experiments to assign solid–state spectra and experiments to extract distance and orientational information. Another key aspect to the success of solid–state NMR is the advances made in sample preparation. These improvements will be reviewed in this contribution. Future prospects for the application of solid–state NMR to interesting biological questions will also briefly be discussed.

scholarly journals Search for Axionlike Dark Matter Using Solid-State Nuclear Magnetic Resonance

2021 ◽  
Vol 126 (14) ◽  
Author(s):  
Deniz Aybas ◽  
Janos Adam ◽  
Emmy Blumenthal ◽  
Alexander V. Gramolin ◽  
Dorian Johnson ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Dark Matter ◽  
Solid State ◽  
Magnetic Resonance ◽  
Nuclear Magnetic
Sign in / Sign up

Export Citation Format

Share Document