Theoretical Investigations of Zintl Anions Analogous to Ozone

Abstract

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.

An All-Metal Aromatic Sandwich Complex [Sb3Au3Sb3]3–

“…The cyclo -Sb 3 in [Sb 3 Au 3 Sb 3 ] 3– also serves as new evidence for the existence of Sb 3 3– fragment upon dissolving K 5 Sb 4 in solvents, which has been put forward for more than 80 years . As predicted by Hagelberg et al, the cyclo -Sb 3 3– is less-preferred compared with the bent ozone style, which was confirmed by Sevov in experiments . Our results indicate that the cyclo -Sb 3 species can be successfully stabilized by the Au 3 ring.…”

“…The calculated Wiberg bond order 31 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 The potential energy surface of Sb 3 3− is known to possess two clear minima, representing two Sb 3 3− species with an equilateral triangle structure and a bent one, respectively. 27 Similar to the isoelectronic ozone molecule, the cyclo-Sb 3 3− is less stable than the bent counterpart (∆E = 0.5 eV). Nevertheless, the two cyclo-Sb 3 in [Sb 3 Au 3 Sb 3 ] 3− (Figure 1) are equilateral triangles with D 3h symmetry, hinting that these Sb 3 ligands are not in Sb 3 3− charge state.…”

Stabilization of Ozone-like [Bi3]3- in the Heteroatomic closo-Clusters [Bi3Cr2(CO)6]3- and [Bi3Mo2(CO)6]3-

“…The distances within the [Pn 3 ] 3- trimers, 2.10 Å for [P 3 ] 3- , 2.374 Å for [As 3 ] 3- , and those of [Bi 3 ] 3- observed in 1 and 2 , are all shorter than the corresponding Pauling's single-bond distances, and manifest their multiple nature. Also, theoretical calculations for [Sb 3 ] 3- have shown that the bent, ozone-like species are more stable than the triangular ones …”

Aromaticity and Antiaromaticity in Zintl Clusters

“…The [Bi 3 ] 3− unit adopts ozone‐like bent configuration, and, therefore, does not appear to be aromatic. Further theoretical calculations for free [Pn 3 ] 3− ions showed that such bent, ozone‐like configuration is lower in energy than the triangular one . It is interesting to note that the reactions of DMF solution of Zintl phase K 3 Pn 7 (Pn=P, As) toward alkynes give rise to 1,2,3‐tripnictolide anions [Pn 3 C 2 H 2 ] − , [Pn 3 C 2 HC 6 H 5 ] − , and [Pn 3 C 2 (C 6 H 5 ) 2 ] − , respectively .…”

“…Further theoretical calculations for free [Pn 3 ] 3À ions showed that such bent, ozone-like configuration is lower in energy than the triangular one. [27] It is interesting to note that the reactions of DMF solution of Zintl phase K 3 Pn 7 (Pn=P, As) towarda lkynes give rise to 1,2,3-tripnictolide anions[ Pn 3 C 2 H 2 ] À ,[ Pn 3 C 2 HC 6 H 5 ] À ,a nd [Pn 3 C 2 (C 6 H 5 ) 2 ] À ,r espectively. [28] The isolobal relationship between CH group and pentele lement makes these 6 p-electron Pn 3 -containing heterocycles heavier analogues of the ubiquitous aromatic cyclopentadienyl anion [C 5 H 5 ] À .…”