| Abstract
| - The suitability of the tetrameric ZnO aggregates[(iPrO)ZnMe]4 (1a) and [(Me3SiO)ZnMe]4 (1b) as potentialsources for molecular models of low-coordinated zinc centersand active sites on zinc oxide catalysts is reported. Theformation and fate of the resulting cationic Zn4O4 degradationproducts by reaction of 1a and 1b with B(C6F5)3 in the presenceof different organic donor substrates have been studied bymeans of ESI mass spectrometry. While 1a affords the cationicmonozinc complexes [MeZn(L)]+ (2a: L = THF, 2b: 15-c-5,2c: DMAP), the cluster 1b furnishes in the presence of DMAP[MeZn(OSiMe3)2Zn(DMAP)2]+ (3), the first dimeric ZnO aggregate cation in solution, and the [MeB(C6F5)3] anion.Additionally, the neutral dinuclear ZnO aggregate [(Me3SiO)Zn(C6F5)thf]2 (4) results from Me/C6F5 exchange reactions asthe final product, which has been characterized by NMRspectroscopy and a single-crystal X-ray diffraction analysis.
- The B(C6F5)3-assisted degradation of the tetrameric ZnO aggregates [(RO)ZnMe]4 (1a: R = iPr; 1b: R = SiMe3) in the presence of different donor solvent substrates has been studied by means of electrospray mass spectrometry, affording remarkable cationic ZnO aggregates as primary products. Thus, 1b reacts with B(C6F5)3 in the presence of p-dimethylaminopyridine to give the first dinuclear ZnO ion pair [3 MeB(C6F5)3], which undergoes Me/C6F5 exchange to form the neutral dimeric ZnO aggregate 4.
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