Electronic Effects on Narcissistic Self-Sorting in Multicomponent Self-Assembly of Fe-Iminopyridine meso-Helicates

Small changes in the-electron-donating ability of coordinating groups have-Substantial effects, on the multicomponent self-assembly of Fe (II)-iminopyridine-based meso-helicate complexes. Both-the nature of the internal diamine core-and the terminal formylpyridine reactants control the rate of the assembly process, the thermodynamic favorability of the meso-helicate products, and the selective incorporation of different aldehyde termini into the assembly. Steric congestion at the coordinating ligands can prevent assembly altogether, and favorable incorporation of,electron-rich aldehyde termini is observed, even though the rate of reaction is accelerated:by the use of.,electron-poor aldehyde reactants. NMR and electrospray ionization mass spectrometry analyses were employed to ,,determine the synergistic nature of narcissistic self-sorting in this system, which depends on both the rigidity of the central core and the electronic donor ability,oft he aldehyde terminus', These experiments illustrate that significant control of self sorting and self-assembly is possible upon extremely small variations in ligand structure, rigidity, arid donor ability.