On June 30, 2019, Oliveras-Gonzalez, Cristina; Linares, Mathieu; Amabilino, David B.; Avarvari, Narcis published an article.Quality Control of [2,2′-Bipyridine]-3,3′-diamine The title of the article was Large Synthetic Molecule that either Folds or Aggregates through Weak Supramolecular Interactions Determined by Solvent. And the article contained the following:
Weak noncovalent interactions between large disk-like mols. in poorly solvating media generally give fibers where the mols. stack atop one another. A particular chiral spacing group between large aromatic moieties, which usually lead to columnar stacks, in this case gives rise to an intramolecularly folded structure in relatively polar solvents, but in very apolar solvents forms finite aggregates. The mol. that displays this behavior has a C3 sym. benzene-1,3,5-tris(3,3′-diamido-2,2′-bipyridine) (BTAB) core with three metalloporphyrin units appended to it through short chiral spacers. Quite well defined chromophore arrangements are evident by CD spectroscopy of this compound in solution, where clear exciton coupled bands of porphyrins are observed In more polar solvents where the mols. are dispersed, a relatively weak CD signal is observed as a result of intramol. folding, a feature confirmed by mol. modeling. The intramol. folding was confirmed by measuring the CD of a C2 sym. analog. The C3 sym. BTAB cores, that would normally be expected to stack in a chiral arrangement in apolar solvents, show no indication of CD, suggesting that there is no transfer of chirality through it (although the expected planar conformation of the 2,2′-bipyridine unit is confirmed by NMR spectroscopy). The incorporation of the porphyrins on the 3,3′-diamino-2,2′-bipyridine moiety spaced by a chiral unit leaves the latter incapable of assembling through supramol. π-π stacking. Rather, modeling indicates that the three metalloporphyrin units interact thanks to van der Waals interactions, favoring their close interaction over that of the BTAB units. Atomic force microscopy shows that, in contrast to other examples of mols. with the same core, disk like (rather than fibrillar one dimensional aggregates) are favored by the C3 sym. mol. The closed structures are formed through non-directional interlocking of porphyrin rings. The chiral spacer between the rigid core and the porphyrin moieties is undoubtedly important in determining the outcome in polar or less polar solvents, as modeling shows that this joint in the mol. has two favored conformations that render the mol. relatively flat, or convex. The experimental process involved the reaction of [2,2′-Bipyridine]-3,3′-diamine(cas: 75449-26-2).Quality Control of [2,2′-Bipyridine]-3,3′-diamine
The Article related to preparation zinc porphyrin supramol mol folded aggregate, mol structure zinc porphyrin supramol mol folded aggregate, cd spectra zinc porphyrin supramol mol folded aggregate and other aspects.Quality Control of [2,2′-Bipyridine]-3,3′-diamine