Derivatives of Bis(2,2′‐bipyridyl)dicyanoiron(II) with Long Alkyl Chains − Versatile Solvatochromic Probes that Form Metalloaggregates in Water‐Rich Media

We report on the preparation, characterisation, and solvatochromic behaviour of four new [FeL2(CN)2] complexes, where L is the ligand 4,4′-diisobutyl-2,2′-bipyridine, 4,4′-di-n-pentyl-2,2′-bipyridine, 4,4′-di-n-heptyl-2,2′-bipyridine, or 4-n-heptyl-4′-methyl-2,2′-bipyridine. The solvatochromic properties of these complexes show that the hydrophobicity imposed by the alkyl chains controls the response of the complexes towards the solvent, and that they are ideal to use as solvation probes in heterogeneous/organised media. An interesting result emerging from this work is the demonstration of the self-aggregating properties of the complexes cis-[Fe(Pe2bpy)2(CN)2], cis-[Fe(He2bpy)2(CN)2], and cis-[Fe(Hebpy)2(CN)2] which are, without doubt, metallosurfactants.