Discrete M2L2 metallacycle and M2L4 cage frameworks and anion competitive reactions of Cu2L4 type receptor

Complexes [Cu2(bitmb)2Cl4] (1), [(CH3OH)(NO3)⊂Cu2(bitmb)4](NO3)3[(CH3OH)(NO3)⊂Cu2(bitmb)4](NO3)3 · CH3OH · 6 H2O (2) and [BF4⊂Cu2(bitmb)4][BF4⊂Cu2(bitmb)4](BF4)3 · 2 CH3OH · 4 H2O (3) are obtained by reaction of bitmb and Cu2+ salts with different anions (BF4-,NO3-orCl-) at different M:L ratio (1:1, 1:2 or 1:2). The results reveal that complex 1 is a neutral Cu2L2 rectangle and complexes 2 and 3 are M2L4 cage-like frameworks with an anion as guest. The anion competitive reaction of the Cu2L4 type receptor with tetrahedral, triangular and spherical anions (ClO4-,BF4-,NO3-andCl-) is reported. The anion competitive experiments demonstrate that the anion selective order is ClO4->BF4->NO3->Cl-, and ClO4- is the biggest and most preferable one, so far.

The structures of a Cu2L2 rectangle and Cu2L4 cage complexes were reported and anion competitive reactions showed that the anion selective order is ClO4->BF4->NO3->Cl-, and ClO4- is the biggest and most preferable one, so far. This M2L4 cage receptor could selectively “recognize” anions of different size and shape in the solid state.Figure optionsDownload as PowerPoint slide