CHEMISTRY OF RARE-EARTH HYPOCOORDINATE OXOCLUSTER CATIONS - FORMATIONOF NOVEL OXOACETATE CLUSTERS

A fast atom bombardment mass spectrometry (FAB MS) study of Ln(CH3COO) (3). 4H(2)O (Ln = Gd (1), Y (2)) was undertaken to explore the chemist ry of hypocoordinate rare earth oxide cations (e.g. [LnO](+) and [Ln(3 )O(4)](+)), which are frequently encountered in FAB MS of rare earth c ompounds. A series of novel rare earth oxoacetate clusters, [Ln(x)O(y) (CH3COO)(3x-(2y+1))](+) (3) was readily and preferentially obtained ov er oxide clusters. Oxygenation is important for the stability of large clusters, i.e. 3, x greater than or equal to 4. Molecules or molecula r ions such as [LnO](+), Ln(2)O(3) and [Ln(3)O(4)](+) are coordinative ly unsaturated, and may have a more extensive coordination chemistry. (C) 1998 Elsevier Science S.A. All rights reserved.