Sequence control in chain-growth polymerization is still one of the most challenging topics synthetic polymer chemistry contrast to natural macromolecules with completely sequence-regulated structures like proteins and DNA. Here, we report quantitative highly selective 1:2 radical copolymerization naturally occurring (+)-d-limonene (L) a maleimide (M) fluoroalcohol giving chiral copolymers high glass transition temperatures (220-250 degrees C) originating from specific rigid cyclic monomers....

Rigid-rodlike right (P)- and left (M)-handed helical polyisocyanides (P-poly-l-1 M-poly-l-1) prepared by the living polymerization of an enantiomerically pure phenyl isocyanide bearing l-alanine pendant with a long n-decyl chain (l-1) μ-ethynediyl Pt−Pd catalyst were found to block copolymerize l-1 d-1 in highly enantiomer-selective manner while maintaining narrow molecular weight distributions. The M-poly-l-1 preferentially copolymerized over antipode factor 6.4−7.7, whereas was P-poly-l-1...

Optically active, amphiphilic poly(meta-phenylene ethynylene)s (PPEa) bearing L- or D-alanine-derived oligo(ethylene glycol) side chains connected to the backbone via amide linkages were prepared by microwave-assisted polycondensation. PPEa's exhibited an intense Cotton effect in π-conjugated main-chain chromophore regions various polar and nonpolar organic solvents due a predominantly one-handed helical conformation stabilized intramolecular hydrogen-bonding network between groups of...

An optically inactive poly(4-carboxyphenyl isocyanide) (poly-1-H) changed its structure into the prevailing, one-handed helical upon complexation with active amines in dimethylsulfoxide (DMSO) and water, complexes show a characteristic induced circular dichroism polymer backbone region. Moreover, macromolecular helicity water aqueous organic solutions containing more than 50 vol % could be "memorized" even after complete removal of chiral (h-poly-1b-H), while that DMSO DMSO−water mixtures...

Bio‐based polymer materials from renewable resources have recently become a growing research focus. Herein, novel thermoplastic elastomer is developed via controlled/living radical polymerization of plant‐derived itaconic acid derivatives, which are some the most abundant acrylic monomers obtained fermentation starch. The reversible addition–fragmentation chain‐transfer (RAFT) polymerizations imides, such as N ‐phenylitaconimide and N‐ ( p ‐tolyl)itaconimide, esters, di‐ n ‐butyl itaconate...

Rodlike polymers with precisely defined architectures are ideal building blocks for self-assembled structures leading to novel nanometer-scale devices. We found that the living polymerization of a single isocyanide enantiomer bearing an l-alanine pendant long n-decyl chain simultaneously produced diastereomeric right- and left-handed helices different molecular weights narrow weight distributions. Each single-handed, rodlike helical polymer controlled length handedness isolated by facile...

It all makes sense: A dynamically racemic helical polymer crystallizes on graphite upon exposure to an organic solvent vapor, resulting in two-dimensional helix-bundle formation. The enantiomeric right- and left-handed blocks separated by reversals can be directly visualized AFM with molecular resolution. Supporting information for this article is available the WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z701546_s.pdf or from author. Please note: publisher not responsible content...

In-situ direct mechanistic transformation from living radical to cationic polymerization was investigated using a trithiocarbonate-type reversible addition−fragmentation chain-transfer (RAFT) agent and an azo-initiator for RAFT of (meth)acrylates followed by the addition Lewis acid catalyst sequential block vinyl ethers. Prior reaction, possibility examined via activation thioester bond acids, such as SnCl4, EtAlCl2, ZnCl2. The CH3CH(OiBu)SC(S)SEt/SnCl4-initiating system induced isobutyl...

Abstract In this study, the stereocomplexation between a novel stereospecific cyclic vinyl polymer, that is, syndiotactic poly(methyl methacrylate) ( st ‐PMMA), with complementary linear isotactic it ‐) PMMA was investigated. Surprising new insight into effects of topology (i.e., end groups), size, and tacticity assembling components on stereocomplex formation obtained. Characterization stereocomplexes revealed self‐assembly ‐PMMAs resulted in an unprecedented “polypseudorotaxane‐type”...

We report a unique hierarchical amplification of chiral information from nonracemic guest to macromolecular helicity, followed by mesoscopic, supramolecular cholesteric twist in water. This remarkable involves two-step chirality transfer processes, which enable the detection and sensing an extremely small imbalance molecules. The helicity with excess single-handed helix was first induced positively charged, chromophoric poly(phenylacetylene), hydrochloride...

Optically active poly(phenylacetylene) copolymers consisting of optically and achiral phenylacetylenes bearing L-alanine decyl esters (1L) 2-aminoisobutylic acid (Aib) as the pendant groups (poly(1L(m)-co-Aib(n))) with various compositions were synthesized by copolymerization 1L Aib using a rhodium catalyst, their chiral amplification macromolecular helicity in dilute solution, lyotropic liquid crystalline (LC) state, two-dimensional (2D) crystal on substrate was investigated measuring...

We report a unique macromolecule consisting of rodlike helical polyisocyanide backbone with narrow molecular weight distribution and rigid mesogenic chiral pendants linked via flexible spacer that exhibits lyotropic nematic latticelike new smectic (lat-Sm) liquid crystal phases at different concentrations. The unprecedented lat-Sm phase is associated the ordering both stiff polymer rigid-rod side groups. A detailed investigation films using X-ray scattering atomic force microscopy revealed...

A water-soluble, hydrochloride of a stereoregular poly(phenylacetylene) bearing an N,N-diisopropylaminomethyl group (poly-1-HCl) as the pendant was found to form predominantly one-handed helix upon complexation with various chiral acids including aromatic and aliphatic carboxylic acids, phosphoric sulfonic amino through noncovalent bonding interactions in water. The complexes exhibited induced circular dichroism (ICD) UV−vis region polymer backbone. Cotton effect signs were same when...

ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTAnomalous Stiff Backbones of Helical Poly(phenyl isocyanide) DerivativesKento Okoshi*†‡, Kanji Nagai†§, Takashi Kajitani†, Shin-ichiro Sakurai†, and Eiji Yashima*†§View Author Information Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology, Japan Science Technology Agency, Japan, Department Molecular Design Engineering, Graduate School Nagoya University, Chikusa-ku, 464-8603, Japan* To whom correspondence should be...

Polymer Langmuir monolayers are an ideal model for two-dimensional (2D) polymer chains, but our understanding of them is still limited. Using atomic force microscopy, we have the first time successfully visualized chain packings in amorphous polyisocyanide deposited on mica. The long which were partially forced to form hairpin-like conformations, sophisticatedly packed 2D film without any stacking. trend persistent lengths polymers films fairly corresponded those 3D chains solution....

The rigid-rod-like left-handed helical polyisocyanides (poly-3) with a different molecular weight and narrow distribution were prepared by the living polymerization of an enantiomerically pure phenyl isocyanide bearing l-alanine pendant n-hexyl chain (3) using μ-ethynediyl Pt−Pd catalyst. poly-3s maintain their feature further copolymerized analogous l-alanine-bound long n-tetradecyl (4) to produce rod−rod diblock controlled sense distribution. rigid copolyisocyanides composed same pendants,...

To understand the selectivity of crown ether type chiral stationary phase (CSP), retention for aniline and positional isomers substituted anilines were studied. In various isomers, except nitroaniline, a remarkable decrease due to steric hindrance was observed 2-substituted isomer. determine detailed molecular recognition mechanism, quantum chemical calculations performed aggregates between anilines. The results suggested that 20-Crown-6, which includes phenyl-substituted 1,1′-binaphthyl...

Abstract A stereoregular poly(phenylacetylene) bearing an N , ‐diisopropylaminomethyl group as the pendant (poly‐ 1 ) changed its structure into prevailing one‐handed helical conformation upon complexation with optically active acids in water. The complexes exhibited induced circular dichroism (ICD) UV/Vis region of polymer backbone. Poly‐ is highly sensitive to chirality chiral and can detect a small enantiomeric imbalance these acids, particular, phenyl lactic acid For example, 0.005 %...