Application of Solid-State ²⁰⁹Bi NMR to the Structural Characterization of Bismuth-Containing Materials

Abstract

Herein, we report the first detailed study of (209)Bi solid-state NMR (SSNMR) spectroscopy of extremely broad central transition powder patterns. (209)Bi ultrawideline SSNMR spectra of several bismuth-containing materials (bismuth oxyhalides, bismuth nitrate pentahydrate, nonaaquabismuth triflate, and bismuth acetate) were acquired at field strengths of 9.4 and 21.1 T using frequency-stepped techniques. The (209)Bi SSNMR experiments at 9.4 T yield powder patterns with breadths ranging from 0.9 to 14.6 MHz, from which quadrupolar coupling constants, C(Q)((209)Bi), between 78 and 256 MHz, were extracted via analytical simulations. The breadths of the quadrupolar-dominated spectra and overall experimental times are greatly reduced for experiments conducted at 21.1 T, which yield high signal-to-noise spectra in which the smaller effects of bismuth chemical shift anisotropy can be clearly observed. The (209)Bi electric field gradient (EFG) and chemical shift (CS) tensor parameters extracted from these spectra are correlated to the molecular structures at the bismuth sites, via first principles calculations of (209)Bi EFG and CS tensors performed using CASTEP for periodic solids and Gaussian 03 for molecular clusters. The rapidity with which (209)Bi SSNMR spectra can be acquired at ultrahigh fields, the sensitivity of the (209)Bi NMR parameters to the bismuth environment, and the predictive power of theoretically calculated NMR interaction tensors suggest that (209)Bi SSNMR may be useful for the characterization of a variety of Bi-containing materials and compounds.

In-situ precipitation synthesis of novel BiOCl/Ag2CO3 hybrids with highly efficient visible-light-driven photocatalytic activity

“…For pure Ag 2 CO 3 , the peaks appearing at 1386 and 887 cm -1 are attributed to the characteristic absorption bands of CO 3 2- [32]. The representative absorption band of pure BiOCl could be found at 519 cm -1 which was assigned to the Bi-O bond stretching vibration [33][34]. Nevertheless, the FT-IR spectra of BiOCl/Ag 2 CO 3 hybrids are similar to those of the main peaks of pure BiOCl and Ag 2 CO 3 .…”

Probing the bulk electronic states of Bi2Se3using nuclear magnetic resonance

“…These values are unusually small compared to f Q = 2.1 MHz for a pure Bi metal and several MHz for other bismuth compounds. 15,16 We then fixed the quadrupolar parameters and let the frequency shift K(θ) as a free fit parameter in the curve fittings for B⊥c and B∠57…”

QUADRELAX: A Program for Computing Relaxation Data for Quadrupolar Nuclei, Including Chemical Exchange Effects

“…[13] by replacing the trigonometric functions appearing in the spherical harmonics according to the following equations This analogy is not unexpected, hence both spherical harmonics Y m 2 's and field gradient V n 's are spherical tensors; therefore, we can replace Y m k 's in Eq. [14] we will have where V 0 m 0 is the field gradient tensor in the coordinate system S 0 . Note that k 5 2 as field gradient is a second order tensor.…”

“…Thus, it is obvious that macromolecules does not satisfy the extreme narrowing condition, and the extension of the relaxation theories and data to other molecular movement regimes beyond the extreme narrowing condition was a need. Although spin 9 2 nuclei have been studied well (14)(15)(16), there were no available theoretical data about their relaxation. Although Bull had considered chemical exchange effect in his 1972 paper, his work was restricted to spin 3 2 nuclei (9).…”