156470-33-6Relevant articles and documents
Non-oxo Chemistry of Manganese in High Oxidation States. Part 1. Mononuclear tert-Butylimido Compounds of Manganese-(VII) and -(VI)
Danopoulos, Andreas A.,Wilkinson, Geoffrey,Sweet, Tracy K. N.,Hursthouse, Michael B.
, p. 1037 - 1050 (2007/10/02)
The interaction of manganese(III) chloride in acetonitrile with NHR(SiMe3) (R = Bu-t or CMe2CH2Me) gave the manganese(VII) species Mn(NR)3Cl as thermally and air-stable green crystals.The chlorine atom in Mn(NBu-t)3Cl 1 has been substituted by Br, OC(O)R (R = Me or CF3), OC6X5 (X = F or Cl), OCH(CF3)2, SC6F5, C6F5 or NHBut by use of SiMe3Br and the silver, thallium or lithium salts of other reagents.Interaction of compound 1 with Ag(O3SCF3) or AgPF6 and NH2Bu-t gave the salts of the cation (1+), with Li(NHBu-t) under selected conditions gave the paramagnetic manganese(VI) analogues of the manganate(VI) anion, 2 , and with HCl gave Mn(NBu-t)2(NHBu-t)Cl2, the reaction being reversed by addition of pyridine.Unstable compounds, e.g.Mn(NBu-t)3(C6F5) and Mn(NBu-t)3(NHBu-t), were characterised spectroscopically.The mechanism of the formation of 1 is discussed together with a mechanism accounting for the instability of compounds where the X-group has β-H atoms as in Mn(NBu-t)3. β-Hydrogen transfer to a NBut group to give a manganese(V) dimer 2 occurs with the formation of ketones from alkoxides; for alkyls decomposition appears to involve homolysis of the Mn-C bond and a radical pathway.The crystal structures of the compounds Mn(NBu-t)3X, X = OC(O)Me, OC6F5, SC6F5, Y, Y = CF3SO3 or PF6 and 2 have been determined.In all the compounds the manganese atom has distorted tetrahedral geometry.In the first three the Mn-N(imido) bond lengths are 1.664(3)-1.673(9) Angstroem and the Mn-N-C angles 139.9(2) to 144,6(3) deg, indicating partial multiple-bond character.The Mn-X distances, 1.91(3), 1.896(2) and 2.289(1) Angstroem respectively indicate single bonds.In the cationic compounds the Mn-N(imido) distances are 1.531(8)-1.655(8) Angstroem, with Mn-N-C angles of 135.8(6)-170.2(9) deg, suggesting more uneven distribution of the Mn-N multiple bonding, although these structures were less precisely determined due to disorder.In the manganate(VI) anion the Mn-N(imido) lenghts are longer, 1.746(3)-1.749(3) Angstroem, as expected.
