Synthesis and Structural Characterization of Mixed‐Ligand Oxorhenium(V) Complexes Containing Bidentate Dithioethers and Monothiolato Ligands

Neutral oxorhenium(V) complexes with dithioether ligands of the general formula [ReOX 3 (RS[CH 2 ] 2 SR)], × = Cl, Br, R = n Bu, Et, Bzl were synthesized. Ammonium perrhenate reacts in concentrated hydrochloric acid with dithiaalkanes (RS[CH 2 ] 2 SR, R = n Bu, Et, Bz) dissolved in glacial acetic acid to give octahedral complexes of the type [ReOCl 3 (RS[CH 2 ] 2 SR)] ( 1a – c ). In concentrated hydrobromic acid, n Bu–S(Ch 2 ) 2 S– n Bu leads to the corresponding tribromo complexes ( 2 ). The X‐ray structure of shows a distorted octahedron with facial coordination of the bromide ligands. The sulfur atoms are cis coordinated to the terminal oxygen. Dissolution o f 1a (R = n Bu) in methanol leads to the substitution of the chloride trans to the oxo ligand by a meth oxy group. The resultant complex [ReOCl 2 (MeO) ( n Bu–S[CHL2] 2 S– n Bu)] ( 3 ) is stable and can be isolated from methanolic solution, but changes to the μ‐oxo‐bridged dirhenium complex μ‐oxobis[dichloro(5,6‐dithiadidodecane)oxorhenium(V)] ( 4 ) when dissolved in other organic solvents. 1a reacts with an excess of benzenethiol by substitution of two chlorides to give the mixed‐ligand complex bis(benzenethiolate)chloro(5,8‐dithiadodecane)oxorhenium(V) ( 5a ). The related 4‐methylbenzenethiolato complex 5b was synthesized starting from the μ‐oxo complex 4 . X‐ray crystal structure determination of 5b shows the equatorial arrangement of the sulfur atoms. The trans position to the oxygen atom is occupied by a chloride ion.