Allan White and Polypyridines: Extending the Lanthanide(iii) Complex Series

X-Ray structure determinations on 41 complexes of lanthanide(iii) halides, principally bromides, with 2,2′-bipyridine, 1,10-phenanthroline, and 2,2′:6′,2″-terpyridine provide a considerable extension to the earlier work of Allan White on such materials and a substantial extension of general work on polypyridine complexes of lanthanide halides. Complexes of 1: 1, 1: 2, and 2: 4 metal-to-ligand composition have been characterised across a broad selection of the lanthanide elements, many of these species showing a higher overall ratio of ligand to lanthanide due to the incorporation of uncoordinated ligand within the crystal lattice. Although stacking of the aromatic entities is apparent in these adducts, in most instances H-bonding of unbound N to coordinated water appears to be the principal interaction involved in their formation.