Premium
Vibrational Spectra of the Cluster Anions [E 4 ] 4– in the metallic Sodium and Barium Compounds Na 4 E 4 and Ba 2 E 4 (E = Si, Ge)
Author(s) -
Somer Mehmet
Publication year - 2000
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200012)626:12<2478::aid-zaac2478>3.0.co;2-a
Subject(s) - chemistry , crystallography , raman spectroscopy , barium , force constant , stereochemistry , molecule , inorganic chemistry , physics , organic chemistry , optics
The vibrational spectra of the cluster anions [E 4 ] 4– (E = Si, Ge) in the metallic compounds Ba 2 E 4 and Na 4 E 4 have been measured and assigned based on the T d symmetry of the discrete tetrahedranide anion. Due to the lower site‐symmetries in the respective crystals all degenerate modes are split, but to different extends. The characteristic breathing frequency ν(E–E) of the [E 4 ] 4– cluster appears exclusively in the Raman spectrum and is almost unaffected by the nature of counterions: ν(E–E) = 486 cm –1 (E = Si) and 276 and 278 (Ge), respectively. The calculated valence force constants f d (Si–Si) = 1.17 Ncm –1 ( Na ); 1.15 Ncm –1 ( Ba ) and f d (Ge–Ge) = 0.98 Ncm –1 ( Na ); 0.94 Ncm –1 ( Ba ) are in good agreement with those previously reported.