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Generation of Gas‐Phase Ge, Sn, and Pb Cluster Anions from Various Sources and Comparison to Solid‐State Analogues
Author(s) -
Fässler Thomas F.,
Muhr HansJoachim,
Hunziker Markus
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199810)1998:10<1433::aid-ejic1433>3.0.co;2-0
Subject(s) - chemistry , desorption , cluster (spacecraft) , ethylenediamine , ion , alkali metal , ionization , phase (matter) , analytical chemistry (journal) , mass spectrometry , inorganic chemistry , crystallography , adsorption , organic chemistry , computer science , programming language , chromatography
Time‐of‐flight mass‐spectrometric investigations show that laser desorption leads to anionic, large clusters of the elements (E) Ge, Sn, and Pb without special gas‐phase clustering conditions and additional ionization processes. Ion formation strongly depends on the nature of the starting materials used during desorption experiments. Cluster anions from pure elements E were observed with a maximum of 6 atoms and their relative intensities decreased exponentially with increasing cluster size. Larger clusters are observed if alkali metals (K, Rb, and Cs) are present. Binary phases of nominal composition K 4 E 9 , ethylenediamine solutions of these phases, and crystalline compounds containing well‐defined cluster anions as in [K([2.2.2]crypt)] 3 E 9 are used as sources for desorption experiments. The latter results in the formation of clusters of 11 (Ge), 15 (Sn), and 13 (Pb) E atoms. Under similar conditions cations are observed at much lower intensities and the maximum cluster size is 6. For E = Ge anions containing two different kinds of atoms KGe n – are observed with relatively high abundance for n = 5, 9, and 10; KGe 11 – and KGe 13 – are also detected. The results are compared to the formation of clusters in binary alloys. Analogies to structurally characterized Zintl ions E n x – ( x = 2, 3, 4) are given. The enhanced formation of cluster anions during the laser desorption process in the presence of electropositive metals indicates a more general application for anion formation in the gas phase.