Self‐Assembly of an Alkali Metal Cluster Stabilized by a New Flexidentate Metalloligand: Formation and Structure of Heterobimetallic Na–Mo and Cs–Mo 2D Networks

A new tridentate ligand, {(3,5‐di‐tert‐butyl‐2‐hydroxybenzyl)amino}acetic acid, has been synthesized. This ligand forms [{Na4(H2O)4(μ‐H2O)2}(Mo2O5L2)2] (1), which contains an Na44+ cluster cation stabilized by [LMoO2(μ‐O)MoO2L]2–, upon reaction with Na2MoO4 in aqueous methanol. This compound has been characterized by various spectroscopic techniques and crystallizes in the triclinic space group P1̄ . Furthermore, compound 1 undergoes smooth exchange of Na+ for Cs+ to give [Cs2(Mo2O5L2)·H2O]n (2) upon treatment with CsCl in aqueous methanol. Similarly, 2 reacts with an excess of NaCl to produce 1. Complex 2 crystallizes in the monoclinic space group C2/c. The crystal structure of this compound reveals that the geometry of the [LMoO2(μ‐O)MoO2L]2– unit stays almost intact but that it stabilizes a polymeric chain of Cs+ cations, unlike in 1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)