Neutral Pentacoordinate and Hexacoordinate Germanium(IV) Complexes:  Valence Expansion At Gemanium By Transannular Bonding Of Selenium in an Eight-Membered Ring¹

Abstract

The neutral pentacoordinate Ge complexes 4 and 5 were prepared and characterized by crystallographic and NMR spectra analysis. The transannular Se atoms in the eight-membered rings of both 4 and 5 are bonded to Ge. The geometry at Ge is displaced 50.3% from tetrahedral to trigonal bipyramidal in 4, and 83.9% to octahedral in 5.

Synthesis, Characterisation and Properties of As‐Monohalogenated Dibenzoarsocines S(C6H4S)2AsHal (Hal = Cl, Br, I) – A Study of the Transannular Interaction S→As

“…[29] This conformation was also found in the iodo-antimony analogue with the shortest transannular interaction for that series and the arsenium cation [S(CH 2 CH 2 S) 2 As] + , which displays the largest BO in the series of arsocanes.…”

Hexacoordinated spirocyclic germanium(IV) complex: Synthesis and structural characterization

“…Attempts to synthesize compound 1 by salt metathesis reaction between the lithium salt O(o-C 6 H 4 SLi) 2 and GeCl 4 , or with the use of GeCl 4 , the free ligand O(o-C 6 H 4 SH) 2 and an amine as an HCl acceptor (methods used in other cases) were unsuccessful [1][2][3]. Therefore, we decided to use Ge(O i Pr) 4 as the source of germanium because its reactivity is lower than that of GeCl 4 and thus the reaction can be easily controlled.…”

“…Therefore, we decided to use Ge(O i Pr) 4 as the source of germanium because its reactivity is lower than that of GeCl 4 and thus the reaction can be easily controlled. Furthermore, the only byproduct of the reaction of Ge(O i Pr) 4 with the ligand O(o-C 6 H 4 SH) 2 would be isopropanol that is volatile and easy to remove, facilitating thus the isolation and purification of the product. Therefore, the reaction between Ge(O i Pr) 4 and the free ligand O(o-C 6 H 4 SH) 2 [6] in a molar ratio 1:2 in refluxing benzene leads to the formation of 1 in high yield (Scheme 1).…”

“…Only three spiro-dibenzogermocine complexes of the type [D(o-C 6 H 4 E) 2 ] 2 Ge (D = Se, S, P-Ph; E = O, S) [1][2][3] and two spiro-germocane complexes [D(CH 2 CH 2 S) 2 ] 2 Ge (D = O, S) [4] (Fig. 1) in which the germanium atom is hexacoordinated have been structurally characterized.…”

“…It was found that in the above-mentioned compounds, the secondary bonding [5] between the donor and the germanium atoms causes the hypercoordination phenomenon of these complexes, resulting in a hexacoordinated germa- nium atom with a distorted octahedral geometry. To continue with our research about the influence of the combination of the donor atoms in the ligand and its rigidity on the strength of the transannular bond, we decided to use the O(o-C 6 H 4 SH) 2 ligand [6].…”