3-Methylisoquinoline N-oxide complexes with 3d metal perchlorates [1

Abstract

The methyl substituent in 3-methylisoquinoline N-oxide (L) exerts significant steric hindrance as to stabilize complexes involving L to metal ratios of less than six with 3d metal(II) perchlorates, as follows: [ML 5(OClO 3)](ClO 4) (M = Mn, Ni); [CoL 5(OClO 3)](ClO 4)· H 2O; [ML 4(OClO 3)](ClO 4) (M = Fe, Cu); and [ZnL 3(OClO 3)](ClO 4)· 3H 2O (tetrahedral). In the case of Cr 3+ and Fe 3+ perchlorates, complexes of the [ML 6](ClO 4) 3 type have been isolated; however, [CrL 4(OClO 3)(OH 2)](ClO 4) 2,[FeL 4(OClO 3) 2](ClO 4) and [FeL 3(OClO 3(OH 2) 2](ClO 4) complexes can be also stabilized, under the influence of the steric affects of L. Finally, during interaction of L with Fe(ClO 4) 3, a mixture of approximately 9 parts of the perchloric acid adduct of L([L 2H](ClO 4)) and 1 part of [FeL 6](ClO 4) 3 was recovered from the filtrate, after separation of the precipitate of the latter complex.