Robertson Alasdair P M, Chitnis Saurabh S, Jenkins Hilary A, McDonald Robert, Ferguson Michael J, Burford Neil
Department of Chemistry, University of Victoria, P.O. Box 3065, Stn CSC, Victoria, BC V8W 3V6 (Canada).
Chemistry. 2015 May 18;21(21):7902-13. doi: 10.1002/chem.201406469. Epub 2015 Apr 15.
The coordination chemistry of the stiboranes Ph4 Sb(OTf) (1 a, OTf = OSO2 CF3 ) and Ph3 Sb(OTf)2 (3) with Lewis bases has been investigated. The significant steric encumbrance of the Sb center in 1 a precludes interaction with most ligands, but the relatively low steric demands of 4-methylpyridine-N-oxide (OPyrMe) and OPMe3 enabled the characterization of [Ph4 Sb(OPyrMe)][OTf] (2 a) and [Ph4 Sb(OPMe3 )][OTf] (2 b), rare examples of structurally characterized complexes of stibonium acceptors. In contrast, 3 was found to engage a variety of Lewis bases, forming stable isolable complexes of the form [Ph3 Sb(donor)2 ][OTf]2 [donor=OPMe3 (6 a), OPCy3 (6 b, Cy=cyclohexyl), OPPh3 (6 c), OPyrMe (6 d)], [Ph3 Sb(dmap)2 (OTf)][OTf] (6 e, dmap=4-(dimethylamino)pyridine) and [Ph3 Sb(donor)(OTf)][OTf] [donor=1,10-phenanthroline (7 a) or 2,2'-bipy (7 b, 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 3 did not form stable complexes with phosphine donors, with reactions instead leading to redox processes yielding SbPh3 and products of phosphine oxidation.
已对四苯基锑（三氟甲磺酸根）（1 a，OTf = OSO₂CF₃）和三苯基锑（三氟甲磺酸根）₂（3）与路易斯碱的配位化学进行了研究。1 a中锑中心显著的空间位阻阻碍了其与大多数配体的相互作用，但4-甲基吡啶-N-氧化物（OPyrMe）和OPMe₃相对较低的空间需求使得[四苯基锑（OPyrMe）][三氟甲磺酸根]（2 a）和[四苯基锑（OPMe₃）][三氟甲磺酸根]（2 b）得以表征，它们是结构已表征的锑鎓受体配合物的罕见实例。相比之下，发现3能与多种路易斯碱结合，形成形式为[三苯基锑（给体）₂][三氟甲磺酸根]₂的稳定可分离配合物[给体 = OPMe₃（6 a）、OPCy₃（6 b，Cy = 环己基）、OPPh₃（6 c）、OPyrMe（6 d）]、[三苯基锑（4-(二甲氨基)吡啶）₂（三氟甲磺酸根）][三氟甲磺酸根]（6 e）以及[三苯基锑（给体）（三氟甲磺酸根）][三氟甲磺酸根] [给体 = 1,10-菲咯啉（7 a）或2,2'-联吡啶（7 b，bipy = 联吡啶）]。这些化合物在固态时表现出显著的结构多样性，并按照其作为配位配合物的归属进行配体交换反应。化合物3与膦给体未形成稳定配合物，反应反而导致氧化还原过程，生成三苯基锑和膦氧化产物。
