title: A bis-sulfonyl O,C,O aryl pincer ligand and its tin(II) complex: synthesis, structural studies, and DFT calculations.
abstract: The efficiency of the deprotonated aryl bis-sulfone [2,6-{(p-tolyl)SO2}2C6H3](-) as an O,C,O-coordinating pincer-type ligand was described. The bis-sulfone precursor was synthesized using a straightforward palladium-catalyzed cross-coupling reaction. As a result of directed ortho metalation (DoM) through sulfonyl groups, a selective lithiation of the aryl group was achieved and the corresponding carbanion was isolated and its structure determined by single-crystal X-ray diffraction analysis. A heteroleptic tin(II) complex has been prepared by a nucleophilic substitution reaction. Crystallographic analysis and DFT calculations indicate that the bis-sulfonyl moiety acts as a new O,C,O-coordinating pincer-type ligand with intramolecular S=O coordination to a tin(II) center. The cis form with the two nonbonded oxygen atoms of the sulfonyl groups on the same side is preferentially obtained.
authors.affiliation: Université de Toulouse, UPS, LHFA, and CNRS, LHFA UMR 5069, 118 Route de Narbonne, 31062 Toulouse (France).
authors.forename: Mohammad
authors.initials: M
authors.lastname: El Ezzi
authors.forename: Romaric
authors.initials: R
authors.lastname: Lenk
authors.forename: David
authors.initials: D
authors.lastname: Madec
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Sotiropoulos
authors.forename: Sonia
authors.initials: S
authors.lastname: Mallet-Ladeira
authors.forename: Annie
authors.initials: A
authors.lastname: Castel
keywords: NMR spectroscopy; carbene homologues; density functional calculations; pincer ligands; tin