Systematics of boron halide complexes with dichalcogenoether ligands – Synthesis, structures and reaction chemistry

Publication date: Available online 26 November 2017 Source:Journal of Organometallic Chemistry Author(s): Coco K.Y.A. Okio, William Levason, Francesco M. Monzittu, Gillian Reid The complexes [BX3(μ-L−L)BX3] (X = Cl, Br, I; L−L = EtS(CH2)2SEt, MeSe(CH2)2SeMe), [BX′3{o-C6H4(SMe)2}] (X’ = Cl, I), [(BBr3)2{o-C6H4(SMe)2}], [(BBr3)2{o-C6H4(SeMe)2}] and [BI3{o-C6H4(SeMe)2}] have been prepared as moisture-sensitive pale solids by reaction of the appropriate BX3 with the dichalcogenoether in anhydrous n-hexane solution, and characterised by microanalysis, IR and multinuclear (1H, 11B, 77Se{1H}) NMR spectroscopy. In contrast, the [BF3(μ-L−L)BF3], [(BF3)2{o-C6H4(SMe)2}] and [(BF3)2{o-C6H4(SeMe)2}], made from BF3 and the neat ligands, are viscous oils which have a significant vapour pressure of BF3 at ambient temperatures. X-ray crystal structures are reported for [BX3{μ-EtS(CH2)2SEt}BX3] (X = Cl, Br, I), [BBr3{μ-MeSe(CH2)2SeMe}BBr3], [BCl3{o-C6H4(SMe)2}] and [(BBr3)2{μ-o-C6H4(SeMe)2}]. The complexes [(BX3)2{MeTe(CH2)3TeMe}] (X = F, Cl, Br) have been identified in solution by multinuclear NMR spectroscopy, but decompose rapidly, whilst o-C6H4(TeMe)2 decomposes immediately on contact with BBr3 or BCl3. Dealkylation of some of the chalcogenoether ligands at room temperature by BI3, to yield complexes including [BI2{o-C6H4S(SMe)] and [BI2{o-C6H4Se(SeMe)], has been identified and the X-ray structure of [BI2{o-C6H4Se(SeMe)] determined. The trends in behaviour al...

Source: Journal of Organometallic Chemistry - November 27, 2017 Category: Chemistry Source Type: research