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Electroactive asymmetric bis-carbazole small molecules bearing cyano functional group(s) were conveniently synthesized and fully characterized by physicochemical and electrochemical methods. These carbazole-based small molecules are colorless in the neutral states and possess reversible redox processes and outstanding thermal stability. The utilization of these bis-carbazole small molecules as the electrochromic materials for the fabrication of electrochromic devices (ECDs) provided high-performance ECDs of high optical contrast up to 99% switching between colorless bleaching state and dark-red colored state and excellent coloration efficiencies of 412 cm2/C. The present work illuminates the excellent qualification of functionalized carbazole-based small molecules in developing efficient ECDs. • Cyano-modified bis-carbazole molecules show high thermal stability, colorless neutral state, and excellent redox properties. • The bis-carbazoles based electrochromic devices (ECDs) exhibit striking color change from colorless neutral states to red. • The ECDs show high optical contrast up to 94−99% and coloration efficiencies of 225−412 cm2/C. • The performances of ECDs were markedly improved by increasing of the number of cyano groups incorporated in carbazole unit. [ABSTRACT FROM AUTHOR]

Abstract: The influences of meso-phenyl substitution on the geometric structure and vibrational spectra have been studied by DFT calculation (B3LYP/6-31G(d)) and experiment on a series of zinc porphyrins (ZnTPP: zinc 5,10,15,20-tetraphenylporphyrin; ZnTrPP: zinc 5,10,15-triphenylporphryin; ZnDPP: zinc 5,15-dipenylporphyirn; ZnMPP: zinc 5-monophenylporphyrin; ZnP: zinc porphine). Calculation indicates that meso-phenyl substitution gives rise to slight out-of-plane distortion but significant in-plane distortion, especially for the configuration around C m atom, to zinc porphyrin. The assignment of experimental vibrational spectra was proposed mainly on the basis of calculation. Different shifting tendency upon meso-phenyl substitution is observed for different structure-sensitive bands, such as the shifting of ν 2, ν 3, ν 6, and ν 8 modes toward higher frequencies and ν 4 and ν 28 modes toward lower frequencies, upon meso-phenyl substitution. This is attributed primarily to in-plane nuclear reorganization effect (IPNR), though the contribution from out-of-plane distortion cannot be excluded completely. Analysis on vibrational structure reveals that asymmetric meso-phenyl substitution, especially the 5,15-diphenyl substitution of ZnDPP, brings about asymmetric vibrational displacement, or even splitting of vibrational structure to normal modes involving mainly the motion of meso-C m. This is ascribed to the reduction of symmetry of porphyrin skeleton caused by asymmetric meso-phenyl substitution. [Copyright &y& Elsevier]

Raman and IR spectra of the free base p-sulfonatophenyl and phenyl meso-substituted porphyrins [5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS4); 5,10,15-tris(4-sulfonatophenyl)-20-phenyl-porphyrin (TPPS3); 5,10-bis(4-sulfonatophenyl)-15,20-diphenylporphyrin (TPPS2A); 5,15-bis(4-sulfonatophenyl)-10,20-diphenylporphyrin (TPPS2O); and 5-(4-sulfonatophenyl)-10, 15,20-trisphenylporphyrin (TPPS1)] and their N-diprotonated derivatives (porphyrin diacids) were studied. The Raman spectra of the deuterated analogues of these porphyrins, in which the central hydrogen atoms were substituted with deuterium, were also measured. The observed vibrational bands were assigned on the basis of the deuteration shifts and compared with the structural analogues of these compounds. In IR spectra of the free-base porphyrins, the p-sulfonation of phenyl groups results in evident alteration for the phenyl modes and the porphyrin skeleton modes that are strongly coupled with phenyl vibrations. While the p-sulfonation of phenyl groups causes only slight changes for the high-frequency Raman bands (>850 cm−1), dramatic shifts and band splitting were observed in the low-frequency region (<500 cm−1) of Raman spectra. The observed differences of low-frequency Raman spectra were attributed to the alteration of the structure of the porphyrin ring, especially the CαCmCα bond-angles, by different meso-sulfonatophenyl substitutions. In addition, different packing style of TPPSn molecules in the aggregates is also responsible for the alteration of the vibrational spectra of the aggregated TPPSn. [Copyright &y& Elsevier]

Abstract: A new receptor based on a dibenzo-18-crown-6 derivative is successfully synthesized and characterized. This receptor reveals selective recognition toward Al3+ ion, along with colorimetric and fluorometric dual-signaling responses based on internal charge transfer (ICT). Also, it can serve as a highly selective chemodosimeter for Al3+ with naked-eye detection. [Copyright &y& Elsevier]

• A benzodiimidazole-COF exhibits tunable adsorption selectivity toward ionic organic dyes. • Selective adsorption of small negative dyes in acidic condition (pH = 3). • Selective adsorption of small positive dyes in basic conditions (pH = 11). • A uniform size endows the COFs with size-excluded adsorption selectivity. Covalent organic frameworks (COFs) have attracted increasing interest during the past decade owing to its potential application in many fields. Herein we report a COF involving both benzodiimidazole and hydroxyphenyl moieties synthesied through Schiff base condensation, in order to trigger their ionization response both under acid and basic conditions. As expected, the benzodiimidazole-COF exhibited pH-induced amphiphilic selective adsorption toward ionic organic dyes, evidenced by selective adsorption of negative methyl orange (256 mg/g) in acidic condition (pH = 3) and positive methyl blue (185 mg/g) in basic conditions (pH = 11), respelctively. This was reasonably ascribed to the elctrostatic interaction between ionic dyes and the ionized COF induced through the protonation of benzodiimidazole ring or the deprotonation of hydroxyphenyl unit. Meanwhile, the ordered micropore of the COF with a uniform size (1.45 nm) endows it with size-excluded adsorption selectivity. This work paves a facile way to construct COFs of amphiphilic selectivity in asdorbing ionic organic dye molecules from waste water. [ABSTRACT FROM AUTHOR]

Highlights: [•] DFT calculations on porphine/C60 bisadducts were carried out. [•] Pyrrolidine ring appended on C60 has influence on its interaction with porphine. [•] Interaction was found between pyrrolidine ring appended on C60 and porphyrin. [•] Charger transfer between pyrrolidine ring and porphine was observed. [•] The red shift of absorption was predicted for fullerene/porphine complexes. [ABSTRACT FROM AUTHOR]