Green plants and algae utilize complicated yet delicate structures to oxidize water into molecular oxygen while releasing electrons for dark reactions.The photocatalytic water oxidation reaction in photosystem Ⅱ is c...Green plants and algae utilize complicated yet delicate structures to oxidize water into molecular oxygen while releasing electrons for dark reactions.The photocatalytic water oxidation reaction in photosystem Ⅱ is challenging as it Involves in transferring multiple electrons and protons and requires a large overpotential.Herein,for the first time,we report that conjugated ladder polymers with suitable band structures are potential metal-free photocatalysts for efficient and stable water oxidation.Two structurally similar conjugat-ed ladder polymers are synthesized via the condensation reaction between amine-and ketone-containing monomers.Photocatalytic tests reveal that different polymer structures exhibit different photocatalytic performances which are determined by their inherent optoelectronics properties.Meanwhile,our first-principles calculations confirm that photocatalytic water oxidation is thermodynamically feasible for both conjugated ladder polymers under visible light irradiation.Our study unveils a novel class of polymer materials for the water oxidation reaction and further indicates that metal-free photocatalysts hold great potential for future solar-to-chemical conversion.展开更多
'Stepwise-coupling polymerization' (SCP) is a very useful approach for preparing microstructure-controllable ordered network polymers, including soluble one-dimensional ladderlike polymers (LP) and tubular pol...'Stepwise-coupling polymerization' (SCP) is a very useful approach for preparing microstructure-controllable ordered network polymers, including soluble one-dimensional ladderlike polymers (LP) and tubular polymers (TP), and two-dimensional sieve-plate polymers. The novel reactive LPs are important precursors of micro-structure controllable polymers such as 'fishbone-' or 'rowboat-' like mesomorphic polymers and their metal complexes as well as tubular polymers (TPs). They are full of great potential for use as advanced materials.展开更多
An ordered ladder polyester （LPE） was first synthesized through the ladder superstructure （LS） constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl （TP）-based π-stackin...An ordered ladder polyester （LPE） was first synthesized through the ladder superstructure （LS） constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl （TP）-based π-stacking by dehydrochlorination condensation using phosgene （COCl2） as coupling agent. LPE was characterized by GPC, FTIR, NMR, XRD, DSC and AFM. Among them, a distinct image of regularly linear alignment corresponding to the ladder main chain of LPE was first revealed by high-resolution AFM.展开更多
A novel soluble, reactive ladder-like polysilsesquioxane (L) with lateral bromophenyl groups was synthesized successfully by stepwise coupling polymerization (SCP) method including preaminolysis, hydrolysis and polyco...A novel soluble, reactive ladder-like polysilsesquioxane (L) with lateral bromophenyl groups was synthesized successfully by stepwise coupling polymerization (SCP) method including preaminolysis, hydrolysis and polycondensation steps. The monomer 3-trichlorosilylpropoxy-4-bromobenzene (M) was first prepared via hydrosilylation reaction catalyzed by dicyclopentadienylplatinum dichloride (Cp2PtCl2). The title polymer (L) was characterized by 1H-NMR, 29Si-NMR, FTIR, X-ray diffraction (XRD), DSC and vapor pressure osmometry (VPO). The experimental results indicate that the polymer (L) possesses a typical ladder-like structure.展开更多
A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was charac...A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was characterized by the XRD, ^29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09A and the ladder thickness t = 3.89A, respectively, which are approximately consistent with the molecular simulation-calculated ones： w＇= 10.60A and t＇= 3.06A. ^29Si NMR displayed a resonance peak with small half peak width, △1/2 - 4 ppm, for the moiety [=Si（Vi）O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.展开更多
A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and...A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.展开更多
In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes （SC-ISEs）, with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjug...In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes （SC-ISEs）, with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjugated polymer, thieno[3,2-b]thiophene （LCPT）, was investigated in fabricating Cu2＋-selective electrodes for the first time. The resulting electrodes were characterized by electrochemical impedance spectroscopy （EIS）, chronopotentiometry, and the water layer test. Results proved that the active LCPT facilitates the ion-to-electron transduction, and avoids the detrimental aqueous layer formed at the interface of SC-ISEs.展开更多
基金the National Key R&D Program of China(Nos.2017YFA0207301 and 2018YFA0208702)the National Natural Science Foundation of China(Nos.21875235 and 21633007)+2 种基金the China Postdoctoral Science Foundation(Nos.BX20200317,2020M682032)the Foundation of the National Synchrotron Radiation Laboratory(No.KY2340000116)the Fundamental Research Funds for the Central Universities.
文摘Green plants and algae utilize complicated yet delicate structures to oxidize water into molecular oxygen while releasing electrons for dark reactions.The photocatalytic water oxidation reaction in photosystem Ⅱ is challenging as it Involves in transferring multiple electrons and protons and requires a large overpotential.Herein,for the first time,we report that conjugated ladder polymers with suitable band structures are potential metal-free photocatalysts for efficient and stable water oxidation.Two structurally similar conjugat-ed ladder polymers are synthesized via the condensation reaction between amine-and ketone-containing monomers.Photocatalytic tests reveal that different polymer structures exhibit different photocatalytic performances which are determined by their inherent optoelectronics properties.Meanwhile,our first-principles calculations confirm that photocatalytic water oxidation is thermodynamically feasible for both conjugated ladder polymers under visible light irradiation.Our study unveils a novel class of polymer materials for the water oxidation reaction and further indicates that metal-free photocatalysts hold great potential for future solar-to-chemical conversion.
文摘'Stepwise-coupling polymerization' (SCP) is a very useful approach for preparing microstructure-controllable ordered network polymers, including soluble one-dimensional ladderlike polymers (LP) and tubular polymers (TP), and two-dimensional sieve-plate polymers. The novel reactive LPs are important precursors of micro-structure controllable polymers such as 'fishbone-' or 'rowboat-' like mesomorphic polymers and their metal complexes as well as tubular polymers (TPs). They are full of great potential for use as advanced materials.
基金This project was financially supported by National Natural Science Foundation of China (Nos. 50073028, 29974036, 20174047, 50273043)National Center for Nanoscience and Technology, China.
文摘An ordered ladder polyester （LPE） was first synthesized through the ladder superstructure （LS） constructed by concerted interactions of hydroxyl- and aramide-based H-bonding and p-terphenyl （TP）-based π-stacking by dehydrochlorination condensation using phosgene （COCl2） as coupling agent. LPE was characterized by GPC, FTIR, NMR, XRD, DSC and AFM. Among them, a distinct image of regularly linear alignment corresponding to the ladder main chain of LPE was first revealed by high-resolution AFM.
基金This work was supported by the National Natural Science Foundation of China (No. 20174047, 20204016, 50273043) andDow Corning Corporation, USA.
文摘A novel soluble, reactive ladder-like polysilsesquioxane (L) with lateral bromophenyl groups was synthesized successfully by stepwise coupling polymerization (SCP) method including preaminolysis, hydrolysis and polycondensation steps. The monomer 3-trichlorosilylpropoxy-4-bromobenzene (M) was first prepared via hydrosilylation reaction catalyzed by dicyclopentadienylplatinum dichloride (Cp2PtCl2). The title polymer (L) was characterized by 1H-NMR, 29Si-NMR, FTIR, X-ray diffraction (XRD), DSC and vapor pressure osmometry (VPO). The experimental results indicate that the polymer (L) possesses a typical ladder-like structure.
文摘A novel, reactive amide-bridged ladder polyvinylsiloxane （abbr. LP） with Mn= 2.4×10^4 was synthesized for the first time by means of aryl amide H-bonding self-assembled template. The regularity of LP was characterized by the XRD, ^29Si NMR and DSC methods. XRD analysis demonstrated the ladder width w = 9.09A and the ladder thickness t = 3.89A, respectively, which are approximately consistent with the molecular simulation-calculated ones： w＇= 10.60A and t＇= 3.06A. ^29Si NMR displayed a resonance peak with small half peak width, △1/2 - 4 ppm, for the moiety [=Si（Vi）O2/2-]n of LP. Besides, as a collateral evidence, DSC measurement revealed a high glass transition temperature Tg = 225℃, suggesting high stiffness of the ladder main chain of LP.
文摘A highly ordered m-phenylenediimino-bridged ladder polyhydrosiloxane （abbr. OLPHS） with Mn = 1.24 × 10^4 was synthesized stoichiometric hydrolysis and dehydrochlorination condensation reaction between Si-Cl and Si-OH bonds. The complete ladder structure of OLPHS has been confirmed by the following three data. Two characteristic Bragg＇s peaks representing the ladder width （w = 0.94 nm） and ladder thickness （t = 0.42 nm） were observed in XRD analysis, which are consistent with those calculated by molecular simulation. The very sharp absorption with a small half-peak width （w1/2 = 0.5 ppm） for [（-HN）HSiO2/2]n moiety of OLPHS in ^29Si NMR spectrum indicated presence of the complete ladder structure. As collateral evidence, a higher glass transition temperature （Tg = 105 ℃） is also recorded in the DSC measurement, implying the high stiffness of ladder chain of OLPHS.
基金financially supported by the National Natural Science Foundation of China(No.21107134)Chinese Academy of Sciences(No.KZCX2-YW-JS208)+1 种基金the Natural Science Foundation of Shandong Province(No.JQ200814)the Taishan Scholar Program of Shandong Province
文摘In recent years, there has been a pronounced interest in solid-contact ion-selective electrodes （SC-ISEs）, with emphasis on the use of conducting polymers as ion-to-electron transducer. In this work, a ladder conjugated polymer, thieno[3,2-b]thiophene （LCPT）, was investigated in fabricating Cu2＋-selective electrodes for the first time. The resulting electrodes were characterized by electrochemical impedance spectroscopy （EIS）, chronopotentiometry, and the water layer test. Results proved that the active LCPT facilitates the ion-to-electron transduction, and avoids the detrimental aqueous layer formed at the interface of SC-ISEs.
