Establishing the Coordination Chemistry of Antimony(V) Cations: Systematic Assessment of Ph4Sb(OTf) and Ph3Sb(OTf)2 as Lewis Acceptors. Issue 21 (15th April 2015)

• Record Type: Journal Article
• Authors: Robertson, Alasdair P. M.; Chitnis, Saurabh S.; Jenkins, Hilary A.; McDonald, Robert; Ferguson, Michael J.; Burford, Neil
• Is Part Of: Chemistry. Volume 21:Issue 21(2015)
• Page Start: 7902
• Page End: 7913
• Publication Date: 2015-04-15
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201406469
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The coordination chemistry of the stiboranes Ph<sub>4</sub>Sb(OTf) (<bold>1 a</bold>, OTf = OSO<sub>2</sub>CF<sub>3</sub>) and Ph<sub>3</sub>Sb(OTf)<sub>2</sub> (<bold>3</bold>) with Lewis bases has been investigated. The significant steric encumbrance of the Sb center in <bold>1 a</bold> precludes interaction with most ligands, but the relatively low steric demands of 4‐methylpyridine‐<italic>N</italic>‐oxide (OPyrMe) and OPMe<sub>3</sub> enabled the characterization of [Ph<sub>4</sub>Sb(OPyrMe)][OTf] (<bold>2 a</bold>) and [Ph<sub>4</sub>Sb(OPMe<sub>3</sub>)][OTf] (<bold>2 b</bold>), rare examples of structurally characterized complexes of stibonium acceptors. In contrast, <bold>3</bold> was found to engage a variety of Lewis bases, forming stable isolable complexes of the form [Ph<sub>3</sub>Sb(donor)<sub>2</sub>][OTf]<sub>2</sub> [donor=OPMe<sub>3</sub> (<bold>6 a</bold>), OPCy<sub>3</sub> (<bold>6 b</bold>, Cy=cyclohexyl), OPPh<sub>3</sub> (<bold>6 c</bold>), OPyrMe (<bold>6 d</bold>)], [Ph<sub>3</sub>Sb(dmap)<sub>2</sub>(OTf)][OTf] (<bold>6 e</bold>, dmap=4‐(dimethylamino)pyridine) and [Ph<sub>3</sub>Sb(donor)(OTf)][OTf] [donor=1, 10‐phenanthroline (<bold>7 a</bold>) or 2, 2′‐bipy (<bold>7 b</bold>, bipy=bipyridine)]. These compounds exhibit significant structural diversity in the solid‐state, and undergo ligand exchange reactions in line with their assignment as coordination complexes. Compound <bold>3</bold> did not form stable complexes with phosphine donors, with reactions instead leading to redox processes yielding SbPh<sub>3</sub> and products of phosphine oxidation.</p> </abstract>