Bis‐Sulfonyl O,C,O‐Chelated Metallylenes (Ge, Sn) as Adjustable Ligands for Iron and Tungsten Complexes

Abstract

The synthesis and characterization of an E2 CE2 bis-sulfonyl aryl pincer ligand and its efficiency for the stabilization of compounds containing low-valent Group 14 elements (Ge and Sn) are reported. Complexation reaction of these metallylenes with iron or tungsten complexes resulted in the modulation of the oxygen atoms of the sulfonyl groups implicated in the stabilization of the Group 14 elements, demonstrating the original adjustable character of the bis-sulfonyl O2 S-C-SO2 aryl pincer.

New phosphorus containing bis-sulfone ligands

“…Based on the good results obtained with the bis-sulfone 1 in the stabilization of low valent group 14 elements and their reactivity, [18,19] the synthesis of phosphorus containing derivatives was also realised. A new dichlorophosphine was obtained with bis-sulfone 1, as shown in Scheme 1, using a slightly modified method from literature.…”

“…[7,20,21] Tri-chlorophosphine was added at low temperature to the carbanion of the bis-sulfone 1, obtained according to previously described methods. [18] …”

“…Bis-sulfone 1 was prepared according to literature procedures. [18] The NMR spectra were recorded with a Bruker Avance II 300 MHz apparatus: 1 H (300.13 MHz, reference TMS), 13 C (75.48 MHz, reference TMS), 31 P (121.51 MHz, reference H 3 PO 4 ) at 298 K and Bruker Avance 400 MHz apparatus: 1 H (400.13 MHz, reference TMS), 13 C (100.61 MHz, reference TMS), 31 P (161.92 MHz, reference H 3 PO 4 ) at 298 K. The signals in the 1 H and 13 C NMR spectra were assigned by COSY ( 1 H), HSQC ( 1 H-13 C), and HMBC ( 1 H-13 C) experiments. The X-ray data were collected at 193(2) K on a Bruker -AXS PHOTON100 D8 VENTURE diffractometer using MoKα radiation (wavelength = 0.71073 Å).…”

“…[20,25] The tolyl groups are situated on opposite sides of the central aromatic ring; the S=O bonds are close to values observed in the case of the previously reported metallylenes with bis-sulfone ligands. [17][18][19] The O1-P1 distance in the dichlorophosphine 2 is of 2.754(3) Å, value between the sum of the covalent radii (1.73 Å) [26] and the sum of the van der Waals radii (3.38 Å), [27,28] while the O3-P1 distance of 3.367(3) Å is almost equal to the sum of the van der Waals radii (3.38 Å). [27,28] The orientation of the sulfonyl groups (the O1, O3) and the phosphorus atom does not make possible an interaction, moreover, in the case of the phosphorus(III) atom, the presence of the lone pair of electron could lead to repulsions with the lone pair of electron on the oxygen atom.…”

“…The importance of bissulfone as ligands was recently highlighted as they function as pincer-type ligands for the stabilization of metallylenes and have an important effect in their reactivity. [17][18][19] …”