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E Hald

Publications and source records attributed to E Hald.

4 recordsLinked to original sources
PubMed2002

A 4-mm probe for (13)C CP/MAS NMR of solids at 21.15 T.

The design of a broadband 4-mm magic-angle spinning (MAS) X-(1)H/(19)F double resonance probe for cross-polarization (CP)/MAS NMR studies at 21.15 T ((1)H at 900 MHz) is described. The high-frequency (1)H/(19)F channel employs a new and efficient transmission line tuning design. The first (13)C CP/MAS NMR spectra recorded at 21.15 T have been obtained with this probe and exhibit the best S/N per milligram sample of hexamethylbenzene achieved so far for a 4-mm rotor.

Benzene Derivatives↗
PubMed2000

Small crystals and small coils in variable-temperature single-crystal NMR.

Time savings by a factor of between 20 and 30 in the acquisition of multinuclear single-crystal (SC) NMR spectra have been obtained for submillimeter-size (0.01 to 0.03 mm(3)) single crystals when compared to recent results for (31)P and (87)Rb SC NMR. This gain in sensitivity is achieved by optimizing the filling factor using the smallest possible rf coil (2.0 mm inner diameter) for the specific SC probe design. Furthermore, this small coil is particularly useful for variable-temperature SC NMR studies. A probe design for such studies is presented and demonstrated experimentally.

Magnetic Resonance Spectroscopy↗
PubMed1998

Improved hardware and software for single-crystal NMR spectroscopy.

Design of state-of-the-art instrumentation and software for acquisition and analysis of single-crystal NMR spectra is presented. The design involves highly accurate rotation of a goniometer, and the acquisition of all the spectra for each rotation axis is automatically controlled by the host computer of the spectrometer using a homebuilt interface between the computer and the single-crystal probe. Moreover, a software package (ASICS) for fast and routine assignment/analysis of complex single-crystal spectra has been developed. Employing this equipment, the acquisition and complete analysis of single-crystal NMR spectra may be performed in about the same time as required for powder methods (spinning or static). The hardware and software are compared to recent alternative approaches within single-crystal NMR. Finally, it has been observed that single-crystal NMR techniques may provide the desired data for samples where powder methods fail.

Computers↗