Accessibility of cation site in zeolites by 6Li MAS NMR spectroscopy using paramagnetic O2 as a chemical shift agent. The example of zeolite Li-LSX
Article Abstract:
Molecular oxygen also functions as a paramagnetic shift agent which distinguishes between the different lithium cation sites of faujasite-type zeolites depending on the accessibility to O2 molecules. The paramagnetic effect of molecular oxygen is affected by its concentration and mobility in the cavities of the zeolite. Nevertheless, both parameters appear to originate from a single factor corresponding to the lifetime of molecules in the vicinity of cations under study. Hence, this phenomenon offers a quantitative method for the discrimination of cationic sites with different accessibility to the molecular probes.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Vibrational investigation of DODC cation for recognition of guanine dimeric hairpin quadruplex studied by satellite holes
Article Abstract:
Local interactions of different structures of G-rich DNA were determined by employing the high-resolution and low-frequency satellite holes (SH) together with vibrations of 3,3'-diethyloxadicarbocyanine cation (DODC+). In addition, a binding structure of dimeric hairpin quadruplex:DODC+ is suggested. The SH findings agree with groove binding model and remove possible ring intercalation in the base pairs of guanine quartet. The implications of the results are discussed.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Conformational change of the cation - anion pair of an ionic liquid related to its low-temperature solid-state phase transitions
Article Abstract:
Low temperature crystalline to crystalline phase transition was examined by ab initio density functional and semiemphirical molecular dynamics calculations. Results showed that during the thermally activated phase transition, the longest dimension of the unit cell (c) was extended due to the increased atomic motions inside the alkyl chain in agreement with the experiments.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 2004
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