Metal-ion chemistry of tetra(meso-4-phenoxy-2-picolyl)-calix[4]pyrrole: An extendable super-cavitand tetrapodal ligand

That calix[4]pyrrole cavitands appended with ligand donor groups should have a rich coordination chemistry is demonstrated by the facile preparation and preliminary investigations of a calix[4]pyrrole adorned with four meso-4-phenoxymethyl-2-pyridyl arms (1); an ESI-FTICR-MS study reveals that 1 selectively binds Cs+ out of the alkali metal ions, whereas the reaction of 1 and [PdCl2(PhCN)2] afforded a novel dimer, [(1)(PdCl2)2], that X-ray crystallography reveals to be chalice-shaped with the PdII centres at the chalice lips and a DMF guest tightly bound within the super-extended cavity and a second DMF guest within the obverse concave annulus formed by the four pyrroles.