When ferrocene and diiron organometallics meet: triiron vinyliminium complexes exhibit strong cytotoxicity and cancer cell selectivity

Abstract

Robust and versatile cationic triiron complexes, obtained from the assembly of ferrocenyl with a di-organoiron structure, display an outstanding cytotoxicity profile, which may be related to redox processes provided by the two metallic components.

Construction of Two-Faced (Hetero)hydrocarbyl Diiron Complexes Mediated by the Interplay of Ligands

“…We selected for the present study the recently reported ferrocenyl-decorated (cyano)amino-allylidene complex 1 . , The reactions of 1 with a series of isocyanides, in isopropanol solution at ca. 100 °C, proceeded with CO-CNR replacement to give the novel compounds 2a–c , which were isolated after workup in moderate to high yields (Scheme ).…”

“…Products were fully characterized by IR and multinuclear NMR spectroscopy; moreover, the structure of 2a , containing a bridging diethyl isocyanomethylphosphonate ligand, was ascertained by X-ray diffraction (Figure and Table ). The replacement of μ-CO by μ-CNCH 2 P­(O)­(OEt) 2 in the structure of 2a does not significantly alter the geometry and bonding parameters of the (cyano)­amino-allylidene ligand, compared to the parent compound 1 and related complexes lacking the ferrocenyl unit. , In particular, both C(2)–C(3) [1.447(14) Å] and C(3)–C(4) [1.418(13) Å] contacts display some π-character, whereas C(2)–N(1) [1.426(12) Å] is essentially a single bond. In agreement with this, N(1) [sum angles 334.4(14)°] shows a considerable pyramidalization, indicative of sp 3 hybridization.…”

“…The carboxylato group in 2c gives rise to an absorption at 1723 cm –1 . In the bis-carbonyl precursor 1 , the stretching vibration related to the terminal carbonyl falls at 1967 cm –1 ; therefore, the replacement of μ-CO with μ-CNR on going from 1 to 2a–c determines a slight increase of the Fe → t-CO π-back-donation.…”

“…Complex 1 was prepared according to the literature procedure. 38 Reactions were conducted under a N 2 atmosphere using standard Schlenk techniques and monitored by liquid IR spectroscopy. Products were conserved under a N 2 atmosphere once isolated.…”

“…Reactants and solvents were purchased from Alfa Aesar, Merck, Strem, or TCI Chemicals and were of the highest purity available. Complex 1 was prepared according to the literature procedure . Reactions were conducted under a N 2 atmosphere using standard Schlenk techniques and monitored by liquid IR spectroscopy.…”