Synthesis and Characterization of Novel Iron(0) Complexes Derived from α,β-Unsaturated-Ketone Analogues with β-Positioned Heteroatoms Containing Covalent and Coordination Bonds

Abstract

Synthesis of novel mono-and dinuclear complexes of Fe(0) are reported displaying both coordination and organometallic bonds. 5-11 were prepared by allowing the new ligands 1-4 to react with Fe 2 (CO) 9 . The structures of the complexes were determined by spectroscopic methods (IR, MS, HR-MS, 1 H and 13 C NMR) and confirmed by single-crystal X-ray analysis.

Novel dinuclear iron(0) complexes from α,β-unsaturated ketones β-positioned with sulfide and sulfoxide groups

“…Our interest in the iron chemistry led us to synthesize new mono and dinuclear Fe(0) complexes which have been prepared by reaction of a,b-unsaturated-ketones analogues containing b-positioned heteroatoms with Fe 2 (CO) 9 [5][6][7][8]. In connection with these studies, we have reported that a,b-unsaturated ligands possessing the dithiol group reacts with diiron nonacarbonyl affording dinuclear complexes (a) [6].…”

Electronic effects on the reactivity of cross-conjugated carbonyl systems with Fe2(CO)9

“…They have the same structural arrangement as the complex 1c, previously reported. 6,11 The IR spectra of these compounds show the typical bands of (M-CO) in 2058 and 2017 cm -1 . The 1 H NMR spectra of 3c and 4c exhibit changes in the assigned signals to the methylene groups, which shifted upfield with respect to ligands.…”

“…These features indicate that an interaction between the sulfur and oxygen atoms through the conjugated system is present, in agreement with the obtained results from IR technique and with described in literature. 6,7 The 1,3-dithiolane ring adopts a half-chair conformation with C 2 axe over C11. Additionally, this moiety presents disorder generating two conformers in 46/54 ratio, only the major contributors are shown in Figure 1.…”

“…8 The new 2 4 ] (9) complexes were obtained in a very low yield and the complex 7 was obtained as a result of both C-S bond activation in the ligand in agreement with our previous studies. 6 This complex has been obtained by other methods. 9 When the coordination reactions were carried out with ligands 3 and 4 (Scheme 4), the formation of four complexes was observed.…”

“…5 In this subject, we have reported that the reactivity of cross-conjugated carbonyl systems -positioned by sulfur atoms towards Fe 2 (CO) 9 , principally produce partial and total C-S bond activation in addition to the formation of 4 -[Fe(CO) 3 ] complexes (Scheme 1). 6 As a part of our constant interest in the understanding of the coordination patterns of this kind of systems, we herein report the study of electronic effects induced by p-substituents on the phenyl ring on the mechanism of reaction of cross-conjugated carbonyls …”