Giving Molecular Cavity Wall Extensions to Pseudo [M(II)7] (M = Co, Ni, Zn) Metallocalix[6]arenes

Upon metal coordination, the upper rim modification of the Schiff base ligand 2-methoxy-6-((methylimino)methyl)phenol gives rise to a new family of [M(II)7] (M = Co, Ni, Zn) pseudo metallocalix[6]arenes in the form of [Co(II)7(OMe)6(L3)6](NO3)2·2H2O·3MeOH (1), [Ni(II)7(OMe)6(L3)6](NO3)2·2H2O (4), [Zn(II)7(OH)2(OMe)4(L3)6](NO3)2·10H2O·4MeOH (5) and [Zn(II)7(OMe)6(L4)6](NO3)2·13H2O·10MeOH (6), where L3H = 2-methoxy-4-phenyl-6-[(methylimino)methyl]phenol and L4H = 2-methoxy-4-tolyl-6-[(methylimino)methyl]phenol. The upper rim functionalisation provides this family with extensions to their molecular cavity walls when compared to their previously reported siblings. Attempts at encapsulating guest moieties (e.g., C60) unexpectedly give rise to the dimeric complex [Co(II)Co(III)(L3)3(NO3)2]·H2O (3).