Hydrogen bonding and fluorous weak interactions in the non-isomorphous {4,4'-bis[(2,2,3,3-tetrafluoropropoxy)methyl]-2,2'-bipyridine-κN,N'}dibromidopalladium and -platinum complexes.

The polyfluorinated title compounds, [MBr(CHFNO)] or [4,4'-(HCFCFCHOCH)-2,2'-bpy]MBr, (1) (M = Pd and bpy is bipyridine) and (2) (M = Pt), have -CHOCHCFCFH side chains with methylene H-atom donors at the α and β sites, and methine H-atom donors at the terminal sites, in addition to aromatic H-atom donors. In contrast to the original expectation of isomorphous structures, (1) crystallizes in the space group C2/c and (2) in P2/n, with similar unit-cell volumes and Z = 4. The asymmetric unit of (1) is one half of the molecule, which resides on a crystallographic twofold axis.