Schwingungsspektren von β‐P₄S₅ und P₄S₇

Abstract

Die Schwingungsspektren der käfigstrukturierten Verbindungen β‐P4S5 und P4S7 wurden für den kristallinen und flüssigen Zustand aufgenommen. Die Zuordnung der Schwingungsfrequenzen wird, vor allem basierend auf Polarisationsdaten, vorgeschlagen. β‐P4S5 zerfällt in der Schmelze in P4S3 α‐P4S7 und β‐P4S6. α‐P4S7 schmilzt unter partieller Dissoziation in β‐P4S6 und S. Für β‐P4S6, wird eine Assoziatbildung mit α‐P4S7 in der Schmelze diskutiert. Die Vorgänge im geschmolzenen P4S7 sind reversibel.

Molecular Vibration Analysis of the Cage-Like Molecules β-P4S5, As4S5, P4S7, and AS2P2S7

“…/?-P 4 S 5 , As 4 S 5 , P 4 S 7 and As 2 P 2 S 7 . In all cases the vibrational frequencies are calculated with satisfactory results, sometimes leading to a slight reassignment of the reported frequencies [6,9]. For AS 2 P 2 S 7 these data were used as a set of reference for completing the assignment.…”

“…This assumption can be used during the assignment of frequencies. The recent spectroscopical investigations [6,7,9] are now supplemented by a normal coordinate analysis. The validity of a highly approximate force field is tested by an application to related molecules, viz.…”

“…P 4 S 7 is one of the thermally stable phosphorous sulfides. Its crystal structure [13,14] and vibrational spectra [6,8,15] are known. As 2 P 2 S 7 was recently investigated by us [7].…”

“…The substitution of As for P will yield a variety of new, sometimes isomeric compounds. Our studies of P-S-, As-S-and As-P-S-compounds [1][2][3][4][5][6][7][8][9] shall now be continued under the aspect of comparable structure elements. The available information on As-P-S-compounds is still very limited [4,8,10].…”

“…For AS 2 P 2 S 7 these data were used as a set of reference for completing the assignment. /?-P 4 S 5 has been characterized by x-ray diffraction [11] and vibrational spectroscopy [6,8], As 4 S 5 is occasionally found after slow evaporation of CS 2 from As 4 S 4 -CS 2 -solutions in form of yellow needles. Crystal data have been given [12] and recently also Raman frequencies were obtained [9].…”