Crystal structures and conformational effects in bis-fluorenyl based ligands and related ruthenium nitrosyl complexes

Abstract

Four crystal structures (two ruthenium complexes and two ligands) are presented containing a bis-fluorene fragment on which alkyl chains (methyl and hexyl) are grafted. The possibility to get both cisoid and transoid conformations in the bis-fluorene units is discussed. A computational investigation using the density functional theory indicates a tendency for a gradual stabilization of the cisoid form, as the length of the chains increases. The effect of the conformation on the charge transfer electronic properties of bis-fluorene based materials is discussed computationally at one-photon absorption (OPA) level and tentatively at two-photon absorption (TPA) levels, but it is found to be modest.