Homo- and heterobimetallic azines derived from ferrocene and cyrhetrene: Synthesis, structural characterization and electrochemical studies

Publication date: Available online 7 December 2018Source: Journal of Organometallic ChemistryAuthor(s): Johana Gómez, Diego Sierra, Mauricio Fuentealba, Vania Artigas, A. Hugo KlahnAbstractA new series of asymmetrical heterobimetallic azines [(η5-C5H5)Fe{(η5-C5H4)C(R) = NNC(R1)-(η5-C5H4)Re(CO)3}] (1–3), a 1,1′-disubstituted ferrocenyl azine [Fe{(η5-C5H4)C(Me) = NNC(H)(η5-C5H4)Re(CO)3}2] (4), and symmetrical homobimetallic cyrhetrenyl azines [{(η5-C5H4)C(R) = N}Re(CO)3]2 (5, 6) have been synthesized and were spectroscopically characterized by FT-IR, NMR, EI-MS and cyclic voltammetry. The molecular structures of 1 and 5 were determined using single-crystal X-ray diffraction technique. Based on the oxidation potential of the ferrocenyl units and the high degree of planarity of the [(C5H4)C(H) = NNC(H)-(C5H4)] system in complex 1, we inferred electronic communication between the electron-withdrawing cyrhetrenyl groups through the π-conjugated azine bridge. The compounds display an (E,E)-configuration about the>CN- bond, an s-trans conformation for the NN bond and an anti-conformation for the two organometallic fragments.Graphical abstractThe synthesis of new organometallic symmetrical homo- and unsymmetrical hetero-bimetallic azines containing a ferrocenyl and cyrhetrenyl moieties are described. Electronic communication between the organometallic fragments was assigned on the bases of E1/2 and coplanarity of the [(C5H4)C(H) = NNC(H)-(C5H4)] system.

Source: Journal of Organometallic Chemistry - December 7, 2018 Category: Chemistry Source Type: research