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Enhancing the Variability of [Ge 9 ] Cluster Chemistry through Phosphine Functionalization
Author(s) -
Wallach Christoph,
Geitner Felix S.,
Klein Wilhelm,
Fässler Thomas F.
Publication year - 2019
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201901673
Subject(s) - chemistry , steric effects , phosphine , reactivity (psychology) , cluster (spacecraft) , aryl , surface modification , alkyl , molecule , crystallography , stereochemistry , silylation , medicinal chemistry , organic chemistry , catalysis , medicine , alternative medicine , pathology , computer science , programming language
The synthetic approach towards molecules that contain Ge atoms with oxidation state 0, and which are exclusively connected to other Ge atoms, is explored by using anionic clusters extracted from binary solids. Besides providing a novel variable method for the introduction of alkenyl moieties to [Ge 9 ] cluster compounds, this work expands the spectrum of mixed‐functionalized [Ge 9 ] cluster anions, which are suitable for the straightforward synthesis of zwitterionic compounds upon coordination to metal cations. In detail, the synthesis of a series of mixed‐functionalized [Ge 9 ] clusters is reported, including [Ge 9 {Si(TMS) 3 } 3 PRR I ] (R= t Bu, R I =(CH 2 ) 3 CH=CH 2 ; 2 ) and [Ge 9 {Si(TMS) 3 } 2 PRR I ] − (R and R I : alkyl, alkenyl, aryl, aminoalkyl; 3 a to 11 a , TMS: (trimethyl)silyl). In 2 and 3 a , pentenyl functionalization of the [Ge 9 ] clusters was achieved by reaction of the novel chlorophosphine t Bu{(CH 2 ) 3 CH=CH 2 }PCl ( 1 ) with silylated [Ge 9 ] clusters. Furthermore, the reactivity of the cluster anions 3 a to 11 a towards NHC Dipp MCl (NHC Dipp =1,3‐di(2,6‐diisopropylphenyl)imidazolylidine; M=Cu, Ag) showed a dependency on the steric demand of the phosphine either zwitterions ( 3 ‐MNHC Dipp to 7 ‐MNHC Dipp ) featuring P–M interactions are formed, or Ge–M coordination ( 8 ‐MNHC Dipp to 11 ‐MNHC Dipp ) occurs. For M=Ag, the formation of zwitterionic complexes was unequivocally proven by NMR investigations showing 1 J ( 31 P‐ 107 Ag/ 109 Ag) spin‐spin coupling.