In‐situ Formation of a Dinuclear Al(III) Complex in Friedel‐Crafts Sulfoxidation of 2‐Naphthol with Thionyl Chloride

A new dinuclear Al(III) complex has been prepared by in situ Friedel‐Crafts sulfoxidation of 2‐naphthol with thionyl chloride (SOCl 2 ) and AlCl 3 as catalyst. The product was characterized by elemental analysis, spectroscopic methods and single crystal X‐ray analysis. X‐ray diffraction indicated that the product is a centrosymmetric dinuclear Al(III) complex, [Al(bn)( μ −OCH 3 )(CH 3 OH)] 2 ( 1 ), where bn 2− is a O 3 ‐donor 1,1′‐sulfonylbis(naphtholate) ligand obtained by in situ reaction of materials. The coordination environment around the Al(III) ions is distorted octahedral (AlO 6 ) and the Al(III) ions are connected together by methoxy bridging ligands. Complex 1 crystallizes in triclinic system and Al(III) ⋅⋅⋅ Al(III) separation is 2.886(2) Å. The dimeric structure is stabilized by two intramolecular O−H⋅⋅⋅O hydrogen bonds, while the intermolecular interactions are provided by C–H⋅⋅⋅ π and π – π contacts.