A¹¹⁵In solid-state NMR study of low oxidation-state indium complexes

Abstract

115 In solid-state NMR (SSNMR) spectroscopy is applied to characterise a variety of low oxidation-state indium(I) compounds. 115 In static wideline SSNMR spectra of several In(I) complexes were acquired with moderate and ultra-high field NMR spectrometers (9.4 and 21.1 T, respectively). 115 In MAS NMR spectra were obtained with moderate and ultra-fast (> 60 kHz) spinning speeds at 21.1 T. In certain cases, variable-temperature (VT) 115 In SSNMR experiments were performed to study dynamic behaviour and phase transitions. The indium electric field gradient (EFG) and chemical shift (CS) tensor parameters were determined from the experimental spectra. With the aid of first principles calculations, the tensor parameters and orientations are correlated to the structure and symmetry of the local indium environments. In addition, calculations aid in proposing structural models for samples where single crystal X-ray structures could not be obtained. The rapidity with which high quality 115 In SSNMR spectra can be acquired at 21.1 T and the sensitivity of the 115 In NMR parameters to the indium environment suggest that 115 In SSNMR is a powerful probe of the local chemical environments of indium sites. This work demonstrates that 115 In NMR can be applied to a wide range of important materials for the purpose of increasing our understanding of structures and dynamics at the molecular/atomic level, especially for the characterisation of disordered, microcrystalline and/or multi-valence solids for which crystal structures are unavailable.

Tailorable Indirect to Direct Band-Gap Double Perovskites with Bright White-Light Emission: Decoding Chemical Structure Using Solid-State NMR

“…Along with the central transition, a broad underlying component, spanning between ca. 500 and −400 ppm, corresponds to the 115 In satellite transitions. , Using the field dependence of the quadrupole coupling interaction, a small C Q ( 115 In) of 1.10 ± 0.25 MHz was calculated for Cs 2 InAgCl 6 (Figure S23). As bismuth is incorporated at low concentrations to form Cs 2 Bi 0.085 In 0.915 AgCl 6 , a second broad 115 In MAS NMR resonance appears at higher frequency at δ cgs = ∼50 ppm ( site-II ), along with the sharp resonance observed for the parent material (Figure b).…”

Experimental and theoretical evidence for hydrogen doping in polymer solution-processed indium gallium oxide

“…S21. The 115 In is a quadrupolar nucleus with spin 9/2 and has a large quadrupole moment Q of 77.0 fm 2 (49). Owing to large Q, the quadrupole interactions dominate, resulting in a very broad linewidth of >1 MHz, which introduces challenges in acquiring the full spectral range (50).…”

Solid‐state nuclear magnetic resonance of spin‐9/2 nuclei 115In and 209Bi in functional inorganic complex oxides

“…[36][37][38][39][40][41] Owing to quadrupolar broadening, 115 In and 209 Bi NMR studies are infrequent. Both nuclei have been studied in a number of halide systems [42][43][44][45][46][47][48][49] and molecular compounds. [48][49][50][51][52][53] Reports on oxides are exceedingly rare.…”

“…Both nuclei have been studied in a number of halide systems [42][43][44][45][46][47][48][49] and molecular compounds. [48][49][50][51][52][53] Reports on oxides are exceedingly rare. A pair of very recent reports suggests growing interest in this area.…”