Self-Sorting of Binuclear Schiff-Base Complexes under Solvent-Free Grinding Conditions

Three binuclear iron(II)) imidazole Schiff-base complexes were constructed by one-pot multicomponent assembly of di(imidazole aldehyde)(A similar to C), 2-aminoethyl (ethyl) amine(D) and Fe(OTf)(2) under solvent-free grinding conditions. X-ray crystallography revealed that the three complexes crystallized in different space groups of Cmca for 1, P2(1)/c for 2 similar to 3. And the molecular structures of 1 similar to 3 all display Fe2L2, arrangement. In complexes 1-3, two ligand strands wrap around two Fe2+ ions and the Fe2+ ions are coordinated to chelating moieties from two imidazole nitrogen atoms and four amine nitrogen atoms, resulting in the pseudo octahedral FeN6 coordination geometry. Taking advantage of the facile approach above, we then investigated the discrimination abilities of the multicomponent assembly process under the solvent-free condition when different components were mixed together (a mixture of D, two kinds of di(imidazole aldehyde) of A similar to C and Fe(OTf)(2)). In this assemble system, combinations [D+A+B+Fe2+] or [D+A+C+Fe2+] adopt narcissistic self-sorting with only two species. while social self-sorting took place in the combination [D+B+C+Fe2+] forming the single heteromer 4, which was composed of two different ligands and exhibited Fe2LL' arrangement. The structure of 4 was further verified by the X-ray analysis by preparing the single crystal of the heteromer 4. To compare the efficiency of solvent-free grindingsolid self-sorting against the solution self-sorting, the conventional solution-based self-sorting reactions were also performed using the same starting materials with equal amount. In consequence of the complexity of H-1 NMR peaks of mixture, the selectivity is poor in solution. Overall, compared with self-sorting in solution. the solvent free grinding self-sorting is more efficient clue to the certain restrictions of molecular movement. CCDC: 1447337, 1; 1447338, 2; 1447339. 3: 1447340, 4.