Trigo-Mouriño P, Navarro-Vázquez A, Sánchez-Pedregal VM. Influence of solvent and salt concentration on the alignment properties of acrylamide copolymer gels for the measurement of RDC.
MAGNETIC RESONANCE IN CHEMISTRY : MRC 2012;
50 Suppl 1:S29-S37. [PMID:
23280658 DOI:
10.1002/mrc.3889]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 09/11/2012] [Accepted: 09/21/2012] [Indexed: 06/01/2023]
Abstract
The dependence of molecular alignment with solvent nature and salt concentration has been investigated for mechanically stretched polyacrylamide copolymer gels. Residual dipolar couplings (RDCs) were recorded for D(2)O, DMSO-d(6), and DMSO-d(6)/D(2)O solutions containing different proportions of the solvents and different sodium chloride concentrations. Alignment tensors were determined by fitting the experimental RDCs to the DFT-computed structure of N-methylcodeinium ion. Analysis of the tensors shows that the degree of alignment decreases with the proportion of DMSO-d(6) as well as with the concentration of sodium chloride, most likely due to enhanced ion-pair aggregation. Furthermore, rotation of the alignment tensor is observed when increasing the salt concentration.
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