Synthesis of methyltrioxorhenium(VII) arylamine complexes and mono- and bis(ortho)-chelated arylaminorhenium(VII) trioxides

From the reaction of MeReO{3} with the neutral arylamine C{6}H{5}CH{2}NMe{2} and the aryldiamine C{6}H{4}(CH{2}NMe{2}){2}-1, 3, have been isolated in good yields the 1/1 adduct complex [MeReO{3}.C{6}H{5}CH{2}NMe{2}], 1, and the21 adduct complex [(MeReO{3}){2} . C{6}H{4}(CH{2}NMe{2}){2}-1,3], 2, respectively. The X-ray molecular structure of 2 shows that both rhenium centres have a trigonal bipyramidal geometry and in the axial positions of each rhenium centre are one of the NMe{2} units of the aryldiamine ligand and a methyl group. The mono(ortho)-chelated arylaminorhenium trioxide complex [ReO{3}{C{6}H{4}CH{2}NMe{2}-2}], 3, can be synthesized by a transmetallation reaction of ClReO{3} with [Zn{C{6}H{4}CH{2}NMe{2}-2}{2}] in a 2:1 molar ratio. In a similar way the bis(ortho)-chelated arylaminorhenium trioxide complex [ReO{3}{C{6}H{3}(CH{2}NMe{2}){2}-2,6}], 4, can be synthesized by addition of a mixture of [Li{2}{C{6}H{3}(CH{2}NMe{2}){2}-2,6}{2}] and ZnCl{2} to ClReO{3}. Complexes 3 and 4 have been isolated as white solids in 66% and 81% yields respectively. The rhenium centre in complex 4 has a bicapped tetrahedral geometry in which the monoanionic {C{6}H{3}(CH{2}NMe{2}){2}-2,6}}-{ ligand is pseudo-facially bonded with a characteristic N1-Re-N2 angle of 107.7(3)}o{, a Re-C{i}{p}{s}{o} bond length of 2.112(11) @?9 and Re-N1 and Re-N2 bond lengths of 2.518(9) @?9 and 2.480(8) @?9 respectively.