Publikationsdatum:
2015-08-11
Beschreibung:
We report on a combined experimental and molecular modelling study on Zn 4 O ion clusters stabilized by acetate molecules (OAc). In particular, ab initio calculations of acetate substitution by hydroxide ions are compared with mass spectrometry data. Though quantum calculations in the gas phase indicate strong energetic preference, no experimental evidence of stable Zn 4 O(OAc) 6−x (OH) x clusters in ethanolic solutions could be observed. This apparent contradiction is rationalized by identifying the supportive role of hydroxide ions for the association of (OAc − → OH − substituted) Zn 4 O(OAc) 6 and Zn 4 O(OAc) 5 + clusters. Mass spectrometry and quantum calculations hint at the stability of (Zn 4 O) 2 (OAc) 12−x (OH) x dimers with x = 1, 2. Therein, the hydroxide ions establish salt-bridges that allow for the formation of additional Zn 3 motifs with the OH above the triangle center—a structural motif close to that of the ZnO-crystal. The association of Zn 4 O(OAc) 6 clusters is thus suggested to involve OAc − → OH − substitution as an activation step, quickly followed by dimerization and the subsequent agglomeration of oligomers.
Print ISSN:
0021-9606
Digitale ISSN:
1089-7690
Thema:
Chemie und Pharmazie
,
Physik
