Exploring the Anticancer Potential of Diiron Bis-cyclopentadienyl Complexes with Bridging Hydrocarbyl Ligands: Behavior in Aqueous Media and In Vitro Cytotoxicity

Gabriele Agonigi,Stefano Zacchini,Nicola Ferri,Valerio Zanotti,Lorenzo Biancalana,Francesca Binacchi,Maria Giovanna Lupo,Fabio Marchetti,Monica Montopoli,Guido Pampaloni,Tarita Biver,Beatrice Campanella

doi:10.1021/acs.organomet.9b00681

Abstract

A series of diiron complexes based on the [Fe2Cp2(CO)x] skeleton (Cp = η5-C5H5, x = 2, 3; η4-C5H5Ph in place of one Cp in one case) and containing different bridging hydrocarbyl ligands (aminocarby...

Highlights

Across the quite large dimensional scale in which organometallic compounds can be classified, ranging from the atomic level to nanometer and micrometer length scales, dimetal complexes occupy a position very close to, distinct from, monometal complexes
The prevalent focus has been so far on diiron complexes closely resembling the [FeFe]-hydrogenase active site,[5] some of us have demonstrated that it is possible to extend these concepts to diiron complexes containing cyclopentadienyls and bridging hydrocarbyl ligands, which cannot be strictly considered as structural mimics but are able to provide new catalytic routes to H2 evolution.[6]
Monoiron compounds have aroused considerable interest due to their possible pharmacological use, and some ferrocene derivatives have clearly emerged in this field

Summary

Introduction

Across the quite large dimensional scale in which organometallic compounds can be classified, ranging from the atomic level to nanometer and micrometer length scales, dimetal complexes occupy a position very close to, distinct from, monometal complexes. Complexes with a metal−metal interaction show a distinct character and chemical behavior, essentially due to two major reasons: (a) cooperative/synergic effects associated with the presence of two adjacent metal atoms and (b) the possibility of taking advantage of unique reactivity patterns provided by bridging coordination.[1] Our interest in this field has been focused on diiron complexes,[2] which represent an area of growing attention for obvious reasons, mostly related to the urgent need to replace precious and toxic metals with more abundant and sustainable metals.[3]. The prevalent focus has been so far on diiron complexes closely resembling the [FeFe]-hydrogenase active site (i.e., dithiolate mimics, see structure II in Figure 1),[5] some of us have demonstrated that it is possible to extend these concepts to diiron complexes containing cyclopentadienyls and bridging hydrocarbyl ligands, which cannot be strictly considered as structural mimics but are able to provide new catalytic routes to H2 evolution (functional mimics).[6]

Methods

Results

Conclusion