Crowding out: ligand modifications and their structure directing effects on brucite-like {M x (μ 3 -OH) y } (M = Co(ii), Ni(ii)) core growth within polymetallic cages.

Previous employment of the ligands 2-methoxy-6-[(methylimino)methyl]phenol (L ₁ H) and 2-methoxy-6-[(phenylimino)methyl]phenol (L ₂ H) has resulted in the self-assembly of pseudo metallocalix[6]arene complexes of general formulae: [M ₇ (μ ₃ -OH) ₆ (L _x ) ₆ ](NO ₃ ) _y (M = Ni(ii), x = 1, y = 2 (1) and Co(ii/iii), x = 2, y = 3 (2)). Extrapolating upon this work, we report the coordination chemistry of ligands 2-methoxy-6-{[(2-methoxyphenyl)imino]methyl}phenol (L ₃ H), 2-[(benzylimino)methyl]-6-methoxyphenol (L ₄ H), 2-[(benzylamino)methyl]-6-methoxyphenol (L ₅ H) and 2-[(benzylamino)methyl]-4-bromo-6-methoxyphenol (L ₆ H), whose structures are modifications of ligands L _1-2 H. These ligands are employed in the synthesis and characterisation of the dimetallic complex [Ni(ii) ₂ (L ₃ ) ₃ (H ₂ O)](NO ₃ )·2H ₂ O·3MeOH (3); the monometallic complexes [Ni(ii)(L ₄ ) ₂ ] (4) and [Co(iii)(L ₄ ) ₃ ]·H ₂ O·MeOH (5a); and the tetranuclear pseudo metallocalix[4]arene complexes: [(NO ₃ )⊂Co(ii) ₄ (μ ₃ -OH) ₂ (L ₅ ) ₄ (H ₂ O) ₂ ](NO ₃ )·H ₂ O (6), [(NO ₃ )⊂Ni(ii) ₄ (μ ₃ -OH) ₂ (L ₅ ) ₄ (H ₂ O) ₂ ](NO ₃ )·H ₂ O (7) and [Ni(ii) ₄ (μ ₃ -OH) ₂ (L ₆ ) ₄ (NO ₃ ) ₂ ]·MeCN (8). The tetrametallic 'butterfly' core topologies in 6-8 are discussed with respect to their structural and topological relationship with their heptanuclear [M ₇ ] (M = Co(ii), Ni(ii)) pseudo metallocalix[6]arene ancestors (1 and 2).