Equilibrium and structure of thallium(III)–ethylenediamine complexes in pyridine solution and in solid

Computational NMR spectroscopy of 205 Tl

We have investigated the NMR chemical shift of 205 Tl in several thallium compounds, ranging from small covalent Tl(I) and Tl(III) molecules to supramolecular complexes with large organic ligands and some thallium halides. NMR calculations were run at the ZORA relativistic level, with and without spin-orbit coupling using few selected GGA and hybrid functionals, namely BP86, PBE, B3LYP, and PBE0. We also tested solvent effects both at the optimization level and at the NMR calculation step. At the ZORA-SO-PBE0 (COSMO) level of theory we find a very good performance of the computational protocol that allows to discard or retain possible structures/conformations based on the agreement between the calculated chemical shift and the experimental value.

Alloyed Crystalline CdSe1-xSx Semiconductive Nanomaterials - A Solid State 113Cd NMR Study

Solid‐state NMR analysis on wurtzite alloyed CdSe_1−xS_x crystalline nanoparticles and nanobelts provides evidence that the ¹¹³Cd NMR chemical shift is not affected by the varying sizes of nanoparticles, but is sensitive to the S/Se anion molar ratios. A linear correlation is observed between ¹¹³Cd NMR chemical shifts and the sulfur component for the alloyed CdSe_1−xS_x (0<x<1) system both in nanoparticles and nanobelts (δ_Cd=169.71⋅X_S+529.21). Based on this correlation, a rapid and applied approach has been developed to determine the composition of the alloyed nanoscalar materials utilizing ¹¹³Cd NMR spectroscopy. The observed results from this system confirm that one can use ¹¹³Cd NMR spectroscopy not only to determine the composition but also the phase separation of nanomaterial semiconductors without destruction of the sample structures. In addition, some observed correlations are discussed in detail.

Trichloridothallium(III) Complexes with Bipyridine Derivatives: From Structure to Luminescence Properties

Several new thallium(iii) complexes, [Tl(4,4′-dmbpy)Cl3(DMSO)]·H2O (1), [Tl(4,4′-dtbpy)Cl3(DMSO)] (2), [Tl(5,5′-dmbpy)Cl3(DMSO)]·(5,5′-dmbpy) (3), and [Tl(6-mbpy)Cl3(DMSO)] (4) (4,4′-dmbpy = 4,4′-dimethyl-2,2′-bipyridine, 4,4′-dtbpy = 4,4′-ditert-butyl-2,2′-bipyridine, 5,5′-dmbpy = 5,5′-dimethyl-2,2′-bipyridine, and 6-mbpy = 6-methyl-2,2′-bipyridine) were prepared from the reaction of TlCl3 with the mentioned ligands in DMSO. The four complexes were fully characterised and their structures were determined by X-ray diffraction. These complexes have a bidendate nitrogenous ligand, a DMSO molecule, and three chloride anions (in the facial position) attached to a TlIII metal centre in a distorted octahedral environment. The stability of the complexes in DMSO is evident by a 203,205Tl–1H spin–spin coupling, determined by 1H NMR spectroscopy. Interestingly, six bond hydrogen–thallium coupling was observed with a coupling constant of 6JTlH = 20 Hz. The absorption and emission spectra of the complexes were investigated. These studies revealed that upon coordination to TlIII, the luminescent intensity is increased in comparison with the related unbound ligands.