Synthesis and Characterization of Hypervalent Organoantimony(III) Compounds Containing the [2‐(Me₂NCH₂)C₆H₄]₂Sb Fragment

Compounds containing the [2‐(Me 2 NCH 2 )C 6 H 4 ] 2 Sb moiety were prepared by using R 2 SbX [X = Cl ( 1 ), Br ( 2 )] as starting materials. The reaction of 1 with Me 3 SiCH 2 MgCl gave the mixed alkyl–aryl stibine R 2 SbCH 2 SiMe 3 ( 3 ). Reduction of 2 with Mg in thf followed by in situ air oxidation or treatment with S 8 resulted in the isolation of (R 2 Sb) 2 E [E = O ( 4 ), S ( 5 )]. Compound 5 is also formed from R 2 SbCl and Na 2 S. The reaction of 4 with [W(CO) 5 (thf)] gives the unexpected complex [(R 2 SbOH)W(CO) 5 ] ( 6 ). The new compounds were investigated by IR, 1 H, and 13 C NMR spectroscopy, as well as by mass spectrometry. The structures of 3 – 6 were determined by single‐crystal X‐ray diffraction. For compounds 3 – 5 , both nitrogen atoms from the pendant arms are involved in intramolecular N→Sb coordination, which results in distorted square‐pyramidal (C,N) 2 SbC or (C,N) 2 SbE (E = O, S) cores. By contrast, in 6 only one nitrogen atom is strongly coordinated to the antimony center, whereas the second nitrogen atom is involved in N ··· H–O bonding. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)