Synthesis and Catalytic Application of Chiral 1, 1-Binaphthyl Polymers

The synthesis of a new type of polymers with main chain chirality based on BINOL skeleton is described. Titanium-BINOLate catalysts are easily generated from these polymers and applied to the asymmetric reaction of Et2Zn with benzaldehyde. The products are obtained in good yields with moderate enantioselectivities.

STUDY ON CHIRAL LIQUID CRYSTALLINE POLYMERS WITH BIPHENYLENE AND AZOBENZENE AS THE MESOGENS

Chiral liquid crystalline polymers containing biphenylene and azobenzene as the mesogensand S(-)-2-methyl-1-butanol as the chiral end group were synthesized and characterized by DSC,POM and X-ray diffraction. These polymers show crystalline or glassy liquid crystalline phase atroom temperature. Most polymers show smectic A or highly ordered smectic phases abovemelting temperature.

STUDY OF CHIRAL SIDE CHAIN LIQUID CRYSTALLINE POLYMERS

Five kinds of side chain liquid crystalline polymers with a chiral component in the pendant group were synthesized and characterized by GPC, polarizing microscopy, DSC, X-ray diffraction ano Dielectric Relaxation Spectroscopy. The liquid crystalline behaviour of the polymers is affected by the length of flexible spacer, which links the mesogenic side chain to the polymer backbone and mesogenic moiety. The characteristic of smectic phase is observed for all the polymers.

Synthesis, Crystal Structure and Properties of a Chiral 3D Supramolecular Coordination Polymer [Co(HL)·(DMF)]_n from 5-(Imidazol-1-ylmethyl)isophthalic Acid

A chiral supramolecular coordination polymer, [Co（HL）·（DMF）]n（1）, with helical chains from a flexible ligand 5-（imidazol-1-ylmethyl）isophthalic acid（H2L） has been obtained under hydrothermal conditions and characterized by elemental analysis, powder X-ray diffraction（PXRD）, IR, Uv/vis spectra, thermal gravimetric analyses（TGA） and also by single-crystal X-ray diffraction. It crystallizes in hexagonal, space group P6522 with a = 8.8109（3）, b = 8.8109（3）, c = 71.771（3） , γ = 120°, V = 4825.3（3） -3, Z = 6, Mr = 695.55, Dc = 1.436 g/cm-3, Rint = 0.0684, F（000） = 2166, the final R = 0.0923 and w R = 0.2697 for 3056 observed reflections（I 2σ（I））. The title coordination polymer 1 shows a chiral layered structure based on right-handed helix chains. Such layers are associated together through hydrogen-bonding interactions to form a 3D supramolecular framework.

SYNTHESIS OF CHIRAL CONJUGATED POLYBINAPHTHYLS BY SONOGASHIRA REACTION

Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-2,2＇-bisbutoxy- 1,1 ＇-binaphthyl （M-2） with 1,2-di（4-bromophenyl）acetylene （M-4） under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.

Facile Synthesis of Chiral Conjugated Polymer Based on BINOL Skeleton

A new type of chiral conjugated polymers 6a-d has been synthesized by the reaction of (R)-2,2'-dihydroxy-1,1'-binaphthyl-6,6'-dicarbaldehyde 5 with corresponding diamine in the presence of acetic acid.

SYNTHESIS OF POLYBINAPHTHYLS INCORPORATING CHIRAL(R)-1,1'-BI-2,2'-NAPHTHOL ENTITIES WITH p-DIVINYLBENZENE BY Pd-CATALYZED HECK REACTION

Polymer and polymer were obtained by the polymerization of (R)-6,6'-dibromo-2,2'-binaphtho-20-crown-6 (M-1) and (R)-6,6'-dibromo-2,2'-di(methoxyethoxymethyloxy)-1,1'-binaphthyl (M-2) with p-divinylbenzene under Pd- catalyzed Heck reaction. The UV, fluorescence and CD spectra of polymer are similar due to the same linkers present in their polymer chain. Polymers can emit strong blue fluorescence and are expected to have potential applications in polarized blue-light emitting sensors. The chiral conjugated polymers exhibit a strong Cotton effect in their circular dichroism (CD) spectra, indicating a high rigidity of polymer backbone.

STUDY ON MAGNETIC FIELD-INDUCED 0RIENTATI0N OF A CHIRAL SIDE-CHAIN LIQUID CRYSTAL POLYACRYLATE USING INFRARED DICHROISM

Magnetic field-induced orientation of a chiral side chain liquid crystalline polyacrylate(P-11) was studied by using IR dichroism. For the investigated P-11, it has been shown thatthe magnetic alignment takes place over the entire temperature range between its meltingpoint and clearing point and the orientation level is strongly temperature-dependent, thedevelopment with time of the magnetic orieatation follows an exponeotial-type relation,and the smectic phase state influences the thermal relaxation process in the absence of themagnetic field.

Polybinaphthyls of (R)-3,3′-Diiodo-2,2′-binaphtho-20-crown-6 with p-Divinylbenzene via Heck Cross-coupling Reaction

The present paper deals with the polymerization of ( R ) 3,3′ diiodo 2,2′ binaphtho 20 crown 6 with \{ p divinylbenzene\} under Heck coupling reaction condition. Both the monomers and the polymer were analyzed by NMR, FTIR, UV, CD, fluorescent spectroscopy, polarimetry, GPC and elemental analysis. The polymer can emit a strong blue fluorescence and is expected to have the potential application in the polarized blue light emitting sensors. The chiral conjugated polymer exhibits a strong Cotton effect in its Circular Dichroism(CD ) spectrum, indicating the high rigidity of the polymer backbone.

Spectroscopic investigation on chirality transfer in additive-driven self-assembly of block polymers

Chiral supramolecules prepared by the additive-driven self-assembly of block copolymers provide a facile method to construct helical nanostructures. In this study, we investigated the chiral transfer from chiral tartaric acid to poly（styrene）-b-poly（ethylene oxide） using small-angle X-ray scattering,transmission electron microscopy, circular dichroism, and vibrational circular dichroism. The results showed that the chirality was transferred to both the segments of block copolymer irrespective of the interaction with the chiral additives and formation of helical phase structure. However, the chirality transfer was carried out using different methods： for poly（ethylene oxide） segments, the chirality transfer was carried out via direct hydrogen bond formation; for polystyrene segments, the chirality transfer was carried out via the cooperative motion of block copolymers during the thermal annealing.

POLYBINAPHTHYLS INCORPORATING (R)-2,2'-BINAPHTHO-20-CROWN-6 AND NAPHTHYL MOITIES

Chiral polymer was synthesized by the polymerization of （R）-6,6＇-bistributylstannyl-2,2＇-binaphtho-20-crown-6 （M-1） with 1,4-dibromo-2,3-bisbutoxy-naphthyl （M-2） by Pd（PPhs）4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution ofracemic amino acid.

Multi‑color Tunable and White Circularly Polarized Luminescent Composite Nanofibers Electrospun from Chiral Helical Polymer

Circularly polarized luminescence(CPL)-active nanomaterials have attracted tremendous attention.However,it is still a big challenge to conveniently fabricate multi-color and white CPL-active nanomaterials on a large scale.Herein,a simple and scalable approach to achieve the above goals is presented.Multicolor CPL-active nanofibers are fabricated from chiral helical substituted polyacetylene,achiral fluorescent dyes and polyacrylonitrile via uniaxial electrospinning;the highest luminescence dissymmetry factor(glum)of the resulting nanofibers can reach 10^(−2).Furthermore,white CPL-active nanofibers are obtained by coaxial electrospinning,in which the resulting core-shell structure has excellent adjustability and can be utilized to physically isolate different fluorescent dyes to reduce energy transfer efficiency;therefore,stable white CPL emissions can be achieved with high g_(lum) values up to 10^(−3).Notably,the prepared white-emission CPL nanofibrous films show bright white circularly polarized light when coated on UV chips,demonstrating their future application in constructing low-cost and flexible light-emitting devices such as circularly polarized light-emitting diodes.

Insights from polymer crystallization： Chirality, recognition and competition

Crystallization of flexible polymer chains reveals distinct characters compared to small molecules, which provides a platform to study molecular self-assembly and morphogenesis. In this review, some examples, e.g., twisting chirality of polymer lamellar crystals, recognition of different chain units and competitive nucleation of different polymorphs and different lamellar thicknesses are briefly discussed. It is shown that the polymer crystallization process far from equilibrium is in practically minimization of the system free energy in local space and finite time, leading to formation of twisted crystals, metastable polymorphism and lamellar crystals with finite thickness. Though each molecule is blind to others, the peculiar ordered configurations with stronger long-range interactions are chosen from the enormous random trials. At the end, we list some remaining questions and outlook the perspectives.

Three-Component Asymmetric Polymerization toward Chiral Polymer

Chiral-polymers with metal-coordination ability showgreat potential formediating asymmetric reactions.However,the synthesis of structurally diverse chiral polymers remains a great challenge,especially doing so efficiently.Herein,four types of Cucatalyzed multicomponent asymmetric polymerizationswere developed using a flexible combination of OBoc-alkyne.

Aggregation-induced emission polymer systems with circularly polarized luminescence

Functional materials with circularly polarized luminescence(CPL)have attracted tremendous attention due to their promising applications in three-dimensional dis-plays,chiral recognition and catalysis,photoelectronic devices,contrast imaging,information encryption,and otherfields.Among various CPL-active materials,poly-meric systems with aggregation-induced emission(AIE)have emerged as excellent candidates because of their efficient aggregate-statefluorescence,large solid-state dissymmetry factor,excellent processibility,diversified self-assembly behaviors,and readily switchable CPL properties.This review summarizes and discusses the recent progress as well as future perspective of diverse AIE polymer systems with CPL,including CPL-active covalent AIE polymers,CPL-active supramolecular AIE polymers,and AIEgen/polymer composites with CPL.According to the loca-tion or introduction method of AIEgen in polymer structures,this review further divides CPL-active covalent AIE polymers into three categories,including polymers with AIEgen in main chains,polymers with AIEgen in side chains,and CPL-active polymers with clusterization-triggered emission.CPL-active supramolecular AIE polymers are discussed based on the driving force for the formation of supramolecular polymers,including host–guest interactions,metal coordination,and other non-covalent interactions.Moreover,examples on the construction of CPL-active AIEgen/polymer composites by physically mixing AIEgens with chi-ral(supra)polymers are also presented.This review is anticipated to provide readers with an overall view on the design strategies of CPL-active AIE polymers,and facil-itate further research on the development of CPL materials and AIE polymers with advanced applications.

Asymmetric Polymerization of N-Vinylcarbazole with Optically Active Anionic Initiators

The anionic polymerization of N-vinylcarbazole（NVC） by using optically active anionic initiators such as the lithium salts of（S）-1-（9H-fluoren-2-yl）-4-isopropyl-4,5-dihydrooxazole（（S）-1-FIDH） and（S）-2-（9H-fluoren-2-yl）-4-isopropyl-4,5-dihydrooxazole（（S）-2-FIDH） and complexes of（-）-Sparteine with n-butylithium（n-Bu Li-（-）-Sp） or fluorenyl lithium（FILi-（-）-Sp） was achieved. The yield and specific rotation of poly（N-vinylcarbazole）s（poly（NVC）s） were considerably affected by the molar ratio of（S）-FIDH to NVC. The highest yield and specific rotation were obtained with Li-（S）-1-FIDH as an initiator, with a molar ratio of monomer and initiator [M]/[I] = 10/1. The effects of the chiral initiators, type of solvent and the polymerization temperature were investigated. The obtained optical activity of polymers was attributed to asymmetric induction of the chiral initiators.