Organoantimony(III) compounds containing (imino)aryl ligands of the type 2-(RN=CH)C6H4 (R=2′,4′,6′-Me3C6H2, 2′,6′-iPr2C6H3): bromides and chalcogenides

The reaction of 2-(RN=CH)C6H4MgBr [R = 2',4',6'-Me3C6H2 (R-1), 2',6'-(Pr2C6H3)-Pr-i (R-2)] [prepared from 2-((RN)-N-1=CH)C6H4Br (1) or 2-((RN)-N-2=CH)C6H4Br (2) and Mg] with SbCl3 in a 2 : 1 and 1 : 1 molar ratio followed by treatment with an aqueous KBr solution gave [2-((RN)-N-1=CH)C6H4](2)SbBr (3) and [2-((RN)-N-2-CH)C6H4](2)SbBr (4) as well as [2-((RN)-N-1=CH)C6H4]SbBr2 (6) and [2-((RN)-N-2=CH)C6H4]SbBr2 (7). Treatment of 4 with Na2S center dot 9H(2)O provided the dinuclear [{2-((RN)-N-2=CH)C6H4}(2)Sb](2)S (5). Heterocyclic species, i.e. the oxide cyclo-[{2-(R2N=CH)C6H4}SbO](3) (8) and the sulfides cyclo-[{2-((RN)-N-1-CH)C6H4}SbS](2) (9) and cyclo-[{2-((RN)-N-2=CH)C6H4}SbS](2) (10), were obtained by reacting dibromides 6 and 7 with KOH and Na2S center dot 9H(2)O, respectively, in a water-toluene solvent mixture. The sulfide 10 reacted with [W(CO)(5)(thf)] to yield the heterometallic complex cyclo-[{2-((RN)-N-2=CH)C6H4}SbS](2)[W(CO)(5)] (11). The compounds were characterised by multinuclear NMR spectroscopy in solution, mass spectrometry and IR spectroscopy in the solid state. The molecular structures of 4, 5, 6 center dot CHCl3, 7, 9 center dot CH2Cl2, 10 and 11 center dot 0.25CH(3)OH were established by single-crystal X-ray diffraction. Theoretical calculations using DFT methods were carried out on bromide 7 and the geometrical isomers of its dimer association as well as the geometrical isomers of sulfide 10 and its monomer.