Structural features of several species based on Sb3 as
a nuclear unit are investigated by ab initio analysis.
In
particular, the applicability of the Zintl−Klemm−Busmann (ZKB)
principle on alkali−antimony clusters of
the form A3Sb3 and
A4Sb3
+ (A = Na, K, Rb) is
examined, which have been detected by mass spectrometric
measurements. It is shown that basic properties pertaining to
geometry, bonding, and stability of these 18
valence electron units display a clear analogy to the respective
features of the isoelectronic ozone molecule.
We conclude that A3Sb3 represents a
case in which the ZKB principle, so far almost exclusively applied
to
solids and liquids, is valid for the gaseous phase as well. An
extension of the ZKB principle, which according
to its traditional meaning involves transfer of charge, to
spin-transfer processes is proposed. Possible
experimental tests regarding the geometries of the species investigated
are pointed out.