S 51. The lower valency states of thorium

Abstract

The possible existence of compounds of bivalent or tervalent thorium has some current tpterest in relation to the position of thorium in the Periodic System, and the so-called Such compounds might indicate whether unutilised valency electrons are disposed in the cerium-like (5f) or the zirconium-hafnium-like ( 6 4 configuration.Thorium di-and tri-iodide have now been prepared and found to be deeply coloured compounds, analogous in every respect to the lower zirconium and hafnium iodides. They are formed by reduction of the tetraiodide with varying quantities of metallic thorium a t 450-550".The tri-iodide is perceptibly volatile ; it undergoes reversible dissociation t o tetra-and di-iodide

Theoretical prediction of atomic and electronic structure of neutral Si6Om (m=1–11) clusters

“…They are identified, in the same table, with the vibration frequencies of the corresponding fragmentation products measured by Anderson and Ogden. 13 It offers an additional evidence of the presence of 2MR and 3MR fragmentation products. Figure 12 shows the HOMO and the LUMO for the best isomer of each system, which presents 2MR, 3MR, or 4MR motif.…”

“…11 Silicon oxides have a fundamental role in the growth of SiNWs because it has been proven experimentally that the yield of SiNWs will be greatly enhanced if silicon oxide is present during the synthesis. 12 The structure and properties of silicon oxides clusters have been studied from both experimental [13][14][15][16] and theoretical points of view. [17][18][19] Photoelectron spectra of some silicon oxide anions have been studied by Wang et al, [14][15][16] providing information about electronic structures of the clusters.…”

Raman-spectroscopy of oligomeric SiO species isolated in solid methane

“…6 During deposition of SiO under matrix conditions monomeric, dimeric and trimeric species have been obtained by means of IR-spectroscopy. [1][2][3] However, no hints for tetrameric SiO have been published so far. The relative amounts of SiO, Si 2 O 2 , and Si 3 O 3 in the matrix depend strongly on the deposition conditions, e.g., the Si:Ar ratio.…”

Redetermination of the crystal structure of ThI4

“…The other tetrahalides of thorium, viz. ThF 4 (von Wartenberg et al, 1923), ThCl 4 (Matignon & Delepine, 1907), ThBr 4 (Nilson, 1882), and the bi-and trivalent compounds ThI 2 (Anderson & D'Eye, 1949) and ThI 3 (Hayek & Rehner, 1949) are also known. In our efforts to synthesize pure actinide halides, we have developed a chemical vapour-transport method (Deubner et al, 2017), which allowed us to obtain single crystals suitable for X-ray diffraction experiments.…”