Aggregation Behavior of Cyclodextrin‐Based [3]Rotaxanes

The aggregation of a cyclodextrin (CD)-based [3]rotaxane has been observed and analyzed in detail for the first time in this work. Although the hexagonal packing aggregation of CD-based polyrotaxane is a well known phenomenon, corresponding studies in terms of rotaxanes without any polymer structure have not been conducted so far, probably owing to the difficulty of the molecular design. We synthesized a series of [3]rotaxane species by using a urea-end-capping method and evaluated their aggregation behavior by XRD and SEM measurements. [3]Rotaxane species containing native CD rings showed clear signals assigned to the hexagonal packing by XRD measurement as did polyrotaxane; this proved their aggregation capability. Because the corresponding per-acetylated derivatives did not show this aggregation behavior, the driving force of this aggregation was suggested to be hydrogen bond formation among CD units. The effect of axle end structures and partial acetylation of CDs were also studied

Synthesis and Post-Polymerization Modification of Poly(N-(4-Vinylphenyl)Sulfonamide)s

Herein, a straightforward synthesis of a novel class of polymers, that is, poly(N-(4-vinylphenyl)sulfonamide)s, and their monomers is reported. A set of monomers with varying electron densities, fine-tuned by different substituents on the aromatic sulfonamide moiety, is polymerized by free radical polymerization featuring low molar masses (2300 ≤ M$_{n}$ ≤ 3200 g mol$^{-1}$) and low dispersities (1.15 ≤ Đ ≤ 1.47). Further, the post-polymerization modification of the obtained polymers via aza-Michael addition with electron-deficient alkenes is demonstrated using organic superbases as catalysts, paving the way toward the facile synthesis of novel polymeric protected β-amino acid derivatives

Polymeric Janus nanorods via anodic aluminum oxide templating

We report a novel method for the fabrication of polymeric Janus nanorods via sequential polymerization from anodic aluminum oxide (AAO) templates. Dual compositions can be incorporated into individual nanorods and endow versatile potential applications. This fabrication strategy paves the way for constructing multifunctional nanostructures and brings together different materials in a single entity

Decarboxylation of Poly[ N ‐(acryloyloxy)phthalimide] as a Versatile Tool for Postpolymerization Modification

Herein the decarboxylation of poly[N-(acryloyloxy)phthalimide] (PAP) for the synthesis of functionalized polymers is reported. PAP homopolymer and block copolymers are used as precursor polymers for the straightforward functionalization via decarboxylation and subsequent Michael-type addition or nitroxide radical coupling (NRC)

Acyclic Diene Metathesis (ADMET) Polymerization of 2,2,6,6-Tetramethylpiperidine-1-sulfanyl (TEMPS) Dimers

The preparation of polymers containing sulfur–nitrogen bond derivatives, particularly 2,2,6,6‐tetramethylpiperidine‐1‐sulfanyl (TEMPS) dimers (i.e., BiTEMPS), has been limited to free‐radical or conventional step‐growth polymerization as result of the inherent thermal lability of the BiTEMPS unit. Accordingly, a novel poly(diaminodisulfide) possessing the BiTEMPS functional group is synthesized via acyclic diene metathesis (ADMET) polymerization at 65–75 °C within 3 h with precise control over the primary polymer structure. Polymer is isolated with an M$_{n}$ of 20 400 g mol$^{-1}$ and Ð of 1.9. Importantly, detailed nuclear magnetic resonance (NMR), size exclusion chromatography, attenuated total reflectance Fourier transform infrared (ATR‐IR) in addition to elemental analysis studies of the BiTEMPS polymer confirm the successful polymerization, and show that the BiTEMPS unit remains intact during the polymerization process. Furthermore, the previously unexplored UV‐responsiveness of the BiTEMPS decorated polymer backbone is investigated for the very first time

Poly(pentafluorobenzyl 2‐ylidene‐acetate): Polymerization and Postpolymerization Modification

The polymerization of 2,3,4,5,6-pentafluorobenzyl 2-diazoacetate is conducted at ambient temperature and catalyzed by [(l-prolinate)RhI(1,5-dimethyl-1,5-cyclooctadiene)] or [(l-prolinate)RhI(1,5-cyclooctadiene)] yielding C1 polymers with molecular weights of 3000–4000 g mol−1 and dispersity between 1.1 and 1.3. Incorporation of the pentafluorobenzyl group into the C1 polymer results in a different solubility when compare to its C2 analog poly(2,3,4,5,6-pentafluorobenzyl methacrylate). Efficient postmodifications via para-fluoro-thiol reaction with different thiols are conducted with this C1 polymethylene