Self-assembly of tris(ureidobenzyl)amines: flexible bricks for robust architectures

Abstract

Despite their high degree of flexibility, tribenzylamine molecules endowed with one ureido group in every arm are avid self-assemblers with a high capacity for self-recognition. Narcissistic self-sorting or chiral self-discrimination events take place when two modules associate giving capsular aggregates. The size of the cavity may be modulated by the relative position of the ureido group and the amino function works as a pH switch of the rupture-reassembly process. When chiral racemic triureas are present the self-assembly is highly diastereoselective.

Supramolecular gel phase crystallization: orthogonal self-assembly under non-equilibrium conditions

“…In a particularly novel recent report laserinduced nucleation has been used to grow crystals in an agarose gel in a highly patterned manner. 33 Another interesting aspect is the use of the chirality of biopolymer gels to influence the handedness of a crystalline product such as sodium chlorate, 60 NaClO 3 . Sodium chlorate is an achiral salt but it crystallises as a conglomerate (mixture of individual left and right handed crystals) in the Sohnke space group P2 1 3.…”

Novel Capsular Aggregates from Flexible Tripodal Triureas with Cs Symmetry

“…They form capsular dimeric aggregates held together by a seam of six hydrogen-bonded urea groups ( Figure 1). [18] Whereas assemblies 1·1 exist as solvent-free capsular aggregates, [19,20] assemblies 2·2 are able to encapsulate guests of appropriate size and shape. [21,22] The tribenzylamine core provides a high degree of flexibility to triureas 1 and 2, which adopt averaged C 3v symmetry in competitive solvents with hydrogen bonds.…”

Self-assembly of tris(2-ureidobenzyl)amines with C 1 symmetry

“…1) [8]. Although larger and more complex assemblies are known, capsular aggregates 1Á1 are attractive and challenging due to their special geometry.…”

“…Although larger and more complex assemblies are known, capsular aggregates 1Á1 are attractive and challenging due to their special geometry. Supramolecular synthons 1 are easily available and have a great potential for modification [8]. Triureas 1 feature averaged C 3v symmetries in competitive solvents with hydrogen bonds.…”

“…However, when two molecules of 1 selfassemble in non-competitive solvents, their conformations are frozen into a chiral one of C 3 symmetry, with a propeller arrangement around the tribenzylamine core. Capsular dimeric aggregates 1Á1 are formed by two self-complementary and enantiomeric tripods (self-discrimination), offset by 60°each other, resulting in a global achiral S 6 symmetry [8].…”