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G Neue

Publications and source records attributed to G Neue.

6 recordsLinked to original sources
PubMed2006

Solid-state (207)Pb NMR studies of lead-group 16 and mixed transition-metal/lead-group 16 element-containing materials.

(207)Pb solid-state NMR studies have been conducted on binary lead-group 16 and mixed transition-metal/lead group 16 materials, correlating the NMR chemical shifts of the materials with their structures. The experimental results show that the (207)Pb chemical shifts are strongly influenced by the local electronic structure. Data are reported for lead selenide, lead selenate, calcium plumbate, strontium plumbite, barium plumbite, lead borate, lead zirconate, lead tungstate, lead meta-tantalate, lead niobate, lead molybdate, lead meta-vanadate, lead sulfite, and lead sulfate.

Journal Article↗
PubMed1999

207Pb NMR of minium, Pb3O4: evidence for the [Pb2]4+ ion and possible relativistic effects in the Pb-Pb bond.

Solid Pb3O4 has been studied with 207Pb nuclear magnetic resonance (NMR) spectroscopy. The 207Pb NMR chemical-shift tensor of the Pb2+ site has principal values of delta11 = 1980 +/- 5 ppm, delta22 = 1540 +/- 5 ppm, and delta33 = -1108 +/- 10 ppm; delta(iso) = 804 +/- 10 ppm. The chemical-shift tensor of the Pb4+ site is axial, with principal values delta(parallel) = -1009 +/- 3 ppm and delta(perpendicular) = 1132 +/- 3 ppm; delta(iso) = -1091 +/- 3 ppm. The Pb4+-Pb2+ scalar coupling constant J(Pb-Pb) = 2.3 +/- 0.1 kHz. The main contribution to the Pb2- chemical-shift anisotropy is proposed to arise from an exchange interaction in the Pb2+-Pb2+ pairs, conventionally regarded as molecular [Pb2]4+ ions.

Cations↗
PubMed1996

Simplification of dynamic NMR spectroscopy by wavelet transforms.

Wavelet transforms considerably simplify the analysis of FIDs influenced by dynamic processes. The projection of data onto an orthonormal set of basis functions which represent well-defined points on a time-frequency plane allows a more natural description of time-dependent frequencies than Fourier transforms. The properties are illustrated by application to simulated NMR signals showing dynamics in the intermediate to slow exchange regime. Construction of highly sophisticated pulse sequences from wavelets is briefly discussed. This very general method will be useful in many areas of magnetic resonance, and theory may benefit as well as imaging.

Data Interpretation, Statistical↗
PubMed1996

Determination of 207Pb2+ chemical shift tensors from precise powder lineshape analysis.

207Pb solid state NMR powder spectra at 296 K are presented for PbSO4, PbMoO4, PbCrO4, PbCO3, PbTiO3, PbZrO3, Pb(NO3)2, Pb(SCN)2, and PbS. Analysis for principal values of the anisotropic chemical shift tensors of the generally very broad spectra included the frequency dependent excitation of the pulse sequence used. Commonly used solid and liquid secondary shift standards for lead were studied with high precision as a function of temperature between 295 K and 315 K to establish a clean 207Pb shift scale. Errors in the existing literature are discussed.

Chemical Phenomena↗
PubMed1994

Fitting of low-intensity wide-line spectra dominated by chemical shift anisotropy.

How experimental parameters affect the appearance, and consequently the fitting, of signals having very wide lines is discussed. As these spectra usually have very low intensities, pulse sequences that remove acoustic ringing and other experimental artefacts have to be used. These pulse sequences introduce further spectral distortions. A FORTRAN 77 program was developed that accounts for these effects. The fitting of these broad spectra is demonstrated by application to 207Pb solid-state nuclear magnetic resonance (NMR) spectra.

Anisotropy↗