Controllable self-assemblies of micro/nano-tubes and vesicles from arylamides and their applications as templates to fabricate Pt micro/nano-tubes and hollow Pt nanospheres

Abstract

A novel class of nonamphiphilic aromatic amides (T1-T3) have been designed and synthesized from naphthalene-2,7-diamine or 2-amino-naphthalene and a 5-hydroxy-isophthalic acid segment, which is revealed to selectively assemble into vesicular or tubular architectures, depending on the solvents and concentrations. T1 and T2 form vesicles in methanol, but can be converted into micro/nano-tubes when water is added and further gelate the binary solvent when the concentration is high enough. In contrast, T3 self-assembles into fine tubular structures in methanol, but can be transformed into vesicles upon being diluted or adding chloroform. The morphology transition has been investigated by SEM, AFM, TEM and fluorescent microscopy, which also reveal that microtubes of large size are formed through the fusion of vesicles of small size, which is driven by the cooperative hydrogen bonding and aromatic stacking interactions, as evidenced by the X-ray investigation on an analogue of T3. The novel organic micro/nano-tubes and vesicles are further used to template the fabrication of Pt micro/nano-tubes or hollow Pt spheres by in situ reduction of the absorbed K 2 PtCl 4 with ascorbic acid, as confirmed by SEM, TEM and EDX analyses.

Two‐Component Fibers/Gels and Vesicles Formed from Hetero‐Double‐Helices of Pseudoenantiomeric Ethynylhelicene Oligomers with Branched Side Chains

“…The thickness of the exterior wall was estimated to be around 2 nm (Figure 7b). Although two‐component vesicles composed of amphiphilic compounds3d, f, 17b, 18 and one‐component vesicles composed of non‐amphiphilic compounds4f, 6, 19 have been found, it should be noted that two‐component vesicle formation by non‐amphiphilic compounds is unprecedented.…”

Can Stacking Interactions Exist Beyond the Commonly Accepted Limits?

“…Stacking or π···π interactions are among the most common (together with hydrogen and halogen bonds) noncovalent interactions found in both natural and synthetic systems . These interactions play a very important role in controlling of the crystal packing − and recognition of aromatic compounds (as the auxiliary stabilizing force), − in regulation of stereoselectivity in synthetic organic reactions, they are significant in biological systems (for example in nucleic acids – DNA and RNA), and also govern the processes important in many areas of science, such as analytical chemistry, medical chemistry, , and nanotechnology. , Thus, the studies on their role in both model and real systems evolved drastically during past decades.…”

Aggregation Behavior of SDS/CTAB Catanionic Surfactant Mixture in Aqueous Solution and at the Air/Water Interface

“…Recently, surfactants have been of tremendous scientific importance because of their many promising applications in detergents, cosmetics, material fabrication, and drug delivery, among other areas. − In addition, several fundamental scientific interests lie behind surfactant systems in the fields of physical chemistry and biology. , The main property of surfactant systems is that their aggregation phenomena arise from various noncovalent interactions (such as π–π stacking, H-bonding, van der Waals interactions) operating at the molecular level. , …”