162441-15-8Relevant articles and documents
Anionic and Cationic Bi- and Tri-nuclear tert-Butylimido Complexes of Manganese-(V) and -(VI)
Danopoulos, Andreas A.,Wilkinson, Geoffrey,Sweet, Tracy K. N.,Hursthouse, Michael B.
, p. 937 - 950 (1995)
Dimeric anionic complexes have been obtained by reduction of MnCl(N-t-Bu)3 or 2 1 with lithium powder in 1,2-dimethoxyethane (dme) to give 22> 2, or with sodium amalgam in tetrahydrofuran (thf) to give 2> 3 which have oxidation states V,V and V,VI respectively.Interaction of 1 with iodine gave a mixed-valence (VI,V,VI) compound, 2Mn>I3 4.Interaction of 3 with HgCl2 gave 2Mn>2*2CHCl3 5a and 2 5b.Oxidation of 1 by silver trifluoromethanesulfonate resulted in an unisolable cation in CH2Cl2, presumably (1+), the EPR spectrum of which suggests that the single electron is located on one N atom of the terminal imide groups.The interaction of this cation with thf resulted in abstraction of H to give the manganese(VI) amido species (1+) which is also formed on protonation of 1 with stoichiometric amounts of CF3SO3H.The amido cation has been isolated with the anions CF3SO3(1-) 6 and (1-) 7, but use of 4>(1-) produces, after crystallisation from toluene, the salts of the amido cation 8 and of an oxo species (1+) 9.Interaction of 2>(1+) in situ with dry O2 gave a mixture 10 of 2Mn>(1+) and 2Mn>(1+) which cocrystallise and cannot be separated.Thermal decomposition of the alkoxide Mn(N-t-Bu)32> gave the manganese(V) dimer .The structures of compounds 3, 4, 5a, 5b, 7, 9 and the mixture 10 have been confirmed by single-crystal X-ray studies.In all cases the Mn atoms have distorted-tetrahedral geometry.The Mn-N bonds to terminal imide ligands lie in the range 1.554-1.674 Angstroem, whilst bridging distances vary considerably from 1.724 to 1.872 Angstroem, reflecting differences for Mn atoms which are co-ordinated only by bridging imides and those which are also bonded to terminal ligands.The Mn-O bonds in the oxo-bridged species are slightly longer than the analogous Mn-N (bridging) distances, indicating less multiple bonding.The structure of the (2-) ion in 5b shows it to conform quite closely to the 'composite' species (2-).
