Lattice Dynamics of Tin Tetrabromide

Abstract

A simple force constant model is developed and applied to the vibrations of solid tin tetrabromide.Three intra-and four intermolecular force constants are adjusted to obtain the best fit t o the crystal field splittings and lattice mode frequencies observed by Raman and infrared spectroscopy. Isotopic and molecular distortion effects are also investigated. The dependence of the Br-Br interaction on separation is found to be similar for SnBr, and Br,.Ein einfaches Kraftkonstantenmodell wird entwickelt und auf die Schwingungen von festem Zinntetrabromid angewendet. Drei Intra-und vier Intermolekularkraftkonstanten werden so justiert, daB sie die beste Anpassung an die Kristallfeldaufspaltungen und mit Raman-und IR-Spektroskopie beobachteten Modenfrequenzcn liefern. Isotopen-und Molekulverzerrungseffekte werden ebenfalls untersucht. Die Abhlingigkeit der Br-Br-Wechselwirkung vom Abstand ist fur SnBr, und Br, Lhnlich.

Vibrational spectra of solid hydrogen sulfide: a lattice dynamics study

“…17 With the structure known and with the wavenumbers of most modes measured and assigned, it now becomes feasible to attempt lattice dynamics calculations to model the vibrations of solid H 2 S and D 2 S in their low-temperature ordered phase. In recent papers, we have developed a simple force constant model, which treats internal and lattice modes in a unified manner, and successfully applied it to a number of simple inorganic molecular crystals such as the halogens, 18 hydrogen halides, 19 -21 carbon disulfide, 22 tin tetrabromide, 23 nitrogen and carbon dioxide, 24 ammonia 25 and sulfur dioxide. 26 In this paper, we describe the application of the model to hydrogen sulfide.…”

Lattice Dynamics of Sulphur Dioxide

“…This is the seventh in a series of papers [l to 61 in which the lattice dynamics of molecular crystals are described by use of a simple spring constant model. Previous work has dealt with the halogens, Cl,, Br,, and I, [l], the low temperature form of the hydrogen halides, HF, HC1, and HBr [2], and carbon disulphide, CS, [3], all linear molecules which form orthorhombic crystals; the spherical top molecule tin tetrabromide, SnBr, [4] which has a monoclinic unit cell; and the cubic crystals of the linear molecules nitrogen and carbon dioxide, N, and CO, [5] and of the symmetric top molecule ammonia, NH, [6]. In this report, we apply the model to the non-linear asymmetric top molecule sulphur dioxide, SO, which forms an orthorhombic crystal.…”

Lattice Dynamics of Ammonia

“…In a recent series of papers from this laboratory [l to 51, a simple spring constant model has been applied to a variety of molecular crystals, such as the orthorhombic crystals of the halogens [ 11, hydrogen halides [2], and carbon disulphide [3], monoclinic tin tetrabromide [4] and the cubic crystals, nitrogen and carbon dioxide [5]. The main advantages of this approach over the more conventional one using intermolecular potentials are its simplicity, its use of a unified treatment of intra-and inter-molecular forces, and its ability to provide information about crystal field splittings of internal modes as well as the frequencies of lattice modes.…”