Zur Darstellung und Kristallstruktur von Tl₂O

Abstract

I n h a l t s i i b e r s i c h t . Es wird erneut iiber die Darstellung von T1,O und erstmalig uber dessen Kristallstruktur berichtet. Die mit Hilfe von FouRIER-Methoden zunachst an einer monoklinen Elementtlrzelle (aM = 6,08,, b M = 3,520, = 108,2", z = 4, Raumgruppe Cib) ermittelten Atomparameter lassen sich bei Annahme spezieller Sauerstofflagen in das hexagonal-rhomboedrische System (Rsumgruppe D& ) transformieren, wonach die T1,O-Struktur als dreifache polytype Form vom Anti-CdJ,-Typ mit % = 3,51,, cH = 37,8, A, c/a = 10,76, Z = 6, Molvol. = 40,7 om3, d,, = 10,44, d, , , = 10,4 g ~m -~ aufzufassen ist. CM = 13,2, if, A b s t r a c t . The preparation of T1,O and its crystal structure is discussed. By Fou-RIER methods for a monoclinic unit cell (aM = 6.08,, b, = 3.52,, cM = 13.2, if, / 3 = 108.2', Z = 4, space group C&j the determined atomic parameters can be transformed into the trigonal system by the assumption of special oxygen positions (space group No. 166-Rgm). Correspondingly the T1,O crystal structure may be described as a threefold polytype form of the antiCdJ, type (aH = 3,51,, cEI = 37.8, A ; cia = 10.76, Z = 6, mol.vo1. = 40.7 cm3; d, = 10.44, d, , , = 10.4 g ~m -~) .

Thermodynamics of the volatilization of thallium(I) oxide from Tl2O, Tl4O3, and Tl2O3

“…T120 was prepared by a previously reported method, the thermal decomposition of T12C03 (Mackay, unstated purity) in argon at 900 K. 23 The phase was confirmed by X-ray diffracti0n.~3 Since the material was produced above the melting point of T120 of about 852 K, it was present as a slab with very Iarge grains rather than as a powder. The phase was confirmed by X-ray diffraction.21,22 Produced in this manner, the T1403 was a gray powder with a metallic luster.…”

“…44 f 0.54) -(8.13 f 0.49) X 103/T (K) (22) log,,K, (atm) = 8.315 -(9.715 X 103)/T(K)(23) The vapor pressure of T120 over Tl2O(c) is in good agreement with the results of Cubicciotti,I4 who used an effusion technique to measure the vapor pressure in the temperature range 620-770 K. At 820 K, we measure a vapor pressure of 2.9 X lo4 atm, while extrapolation of Cubicciotti's data yields 2.4 X 10-4 atm.Our measurements indicate a heat of sublimation A1H0s30 forTl2O(c) of 185.8 kJ/mol, compared to Cubicciotti's value at 700 K, A l P 7~, of 177.8 f 1.2 kJ/mol. In addition, our results yield a heat of vaporization of T120(1) at 900 K of 155.6 f 9.3 kJ/mol.…”

Tl2S: Re-Determination of Crystal Structure and Stereochemical Discussion

“…For Tl 2 O only the main features of the atomic arrangement are known with certainty (27,28). Although the Tl atoms are arranged essentially in the hexagonal close packing as in Tl 2 S, the two compounds are definitely not isostructural in detail.…”

Structure cristalline du sulfure de thallium: Tl4S3

“…Les distances interatomiques entre les 3 derniers atomes de thallium sont identiques aux distances T1-T1 observ6es dans les compos6s du thallium tels que T13BO3 (Marchand, Piffard & Tournoux, 1973) et T120 (Sabrowsky, 1971). L'atome Tl(2) aun environnement de 5 atomes de soufre.…”