Neutral, Cationic, and Anionic Alkyl Derivatives of Tungsten Bonded to a Calix[4]arene Oxo Surface.

The chemically reversible reduction of [(Me)2 W(calix)] to the diamagnetic [(Me)2 W(calix)Na2 ] [Eq. (1)], without major changes in the connectivity of the molecule, illustrates the flexibility of the calixarene ligand and stresses its potential as a molecular functional model of heterogeneous oxo surfaces.