J. Am. Chem. Soc., 129 (49), 15144 -15146, 2007. 10.1021/ja0760832 S0002-7863(07)06083-0
Web Release Date: November 15, 2007

Copyright © 2007 American Chemical Society

A Fan-Shaped Polynuclear Gd6Cu12 Amino Acid Cluster: A "Hollow" and Ferromagnetic [Gd6(3-OH)8] Octahedral Core Encapsulated by Six [Cu2] Glycinato Blade Fragments

Shengchang Xiang, Shengmin Hu, Tianlu Sheng, Ruibiao Fu, Xintao Wu,* and Xudong Zhang

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PRC

wxt@ fjirsm.ac.cn

Received August 13, 2007

Abstract:

By a stepwise growth process, an axial-fan-like and high-nuclearity [Gd6Cu12] cluster compound (1) was obtained, in which six [Cu2] blade fragments encapsulate a "hollow" [Gd6(3-OH)8] octahedral core. Without the support of a centered 6-O ligand for the octahedral core, its mean Gd-3-O-Gd bridging angle () is the largest one among the polynuclear [Gdn] (n 3) clusters. From the exchange and structural parameters of the reported complexes containing the GdO2Gd unit, an empirical formula was at the first time obtained. It can be concluded that > 110.9 is a prerequisite for a GdO2Gd complex exhibiting molecular ferromagnetism. The positive exchange constants for the Gd-Gd coupling from the empirical estimation and data fitting suggest the [Gd6] core in 1 is the first example of high-nuclearity Lnn cluster exhibiting the molecular ferromagnetism. The magnetic property for 1 is mainly predominated by the antiferromagnetic interaction of Cu-Cu coupling and the ferromagnetic interactions of Gd-Gd and of Gd-Cu coupling. At low field, 1 is a frustrated ferrimagnet, while it exhibits a single-ion behavior of Gd3+ ions at high field.

Download the full text: PDF | HTML