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We have demonstrated a single‐crystal‐to‐single‐crystal (SCSC) transformation from a two‐dimensional noninterpenetrated layer to a microporous three‐dimensional fourfold interpenetrated MOF. The centrosymmetric [Co2(μ2‐OH)(EIBA)3]n (SNUT‐25) transforms into a microporous [Co(EIBA)2]n (SNUT‐26), which is triggered by the reaction time with DMF that acts as a structure‐directing agent (HEIBA = 4‐(2‐ethyl‐1H‐imidazol‐1‐yl)benzoic acid; DMF = N,N′‐dimethylformamide). Despite the distinct structure and coordination arrangements of SNUT‐25 in contrast to SNUT‐26, both Co‐MOFs were synthesized using the same ligand. Fascinatingly, upon introducing a specific quantity of DMF combined with a negligible proportion of nitric acid, SNUT‐25 will progressively and completely transform into SNUT‐26. Under the synergistic induction of solvent molecules and temperature, SNUT‐25 changed from the original two‐dimensional layered structure to the three‐dimensional pore structure of SNUT‐26. In addition, SNUT‐25 and SNUT‐26 are efficient photocatalysts for the degradation of organic dye methyl blue (MB) under visible light irradiation. Surprisingly, the degradation rates of both SNUT‐25 and SNUT‐26 can reach over 96%. In addition, SNUT‐25 and SNUT‐26 also exhibited high electrocatalytic oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

C28H31N8O8Co, monoclinic, P21/c (no. 14), a = 14.8071(17) Å, b = 19.676(2) Å, c = 10.8580(13) Å, V = 3066.7(6) Å3, Z = 4, Rgt(F) = 0.0377, wRref(F2) = 0.1228, T = 293(2) K.

To develop efficient sensitizers, five novel metal‐free dyes were designed based on one of the best dyes W05 by inserting auxiliary electron acceptors. The photovoltaic performance of new dyes was studied by density functional theory (DFT) and time‐dependent DFT (TDDFT) calculations in order to shed light on how the auxiliary electron acceptor influences on the photovoltaic performances. Results illustrated that the insertion of auxiliary electron acceptors can narrow the HOMO‐LUMO gap, red‐shift the light absorption band, and enhance the sunlight harvesting. By estimating three important photovoltaic parameters, the photoelectric conversion efficiency (PCE) of W05 was estimated to be about 8.96%, in good agreement with its experimental value of 9.22%, indicating that the scheme calculated the photovoltaic parameters is reliable. Interestingly, the estimated PCE values for designed dyes are superior to that of W05, suggesting that the molecular design is reasonable. Especially 5, its PCE was predicted to be as high as 14.07%, indicating that 5 is a promising sensitizer candidate for DSSC applications. [ABSTRACT FROM AUTHOR]

A nitro substituted azo-chalcone derivative 3-(4-(dimethylamino) phenyl) diazenyl)phenyl)-1-(4-nitrophenyl) prop-2-en-1-one (AZOC-4N) and a reference compound 3-(4-(dimethylamino) phenyl) diazenyl) phenyl)-1-phenylprop-2-en-1-one (AZOC-H) were synthesized by Claisen Schmidt reaction. Thermogravimetry, UV-vis and cyclic voltammetry were used to study the influence of the introduction of nitro in the conjugated molecule AZOC-4N on the photoelectric properties. The active layer was further prepared by solution spin coating, and the morphology of the film was characterized by AFM. The electrical memory performance of the device is studied. It is found that the device has the nonvolatile binary write once read many (WORM) memory performances, and the threshold voltage of the device prepared by introducing nitro group into the molecule is lower—1.4 V. Finally, the electrical memory performance of the device is analyzed by theoretical calculation. [ABSTRACT FROM AUTHOR]

C28H31N8O8Co, monoclinic, P21/c (no. 14), a = 14.8071(17) Å, b = 19.676(2) Å, c = 10.8580(13) Å, V = 3066.7(6) Å3, Z = 4, Rgt(F) = 0.0377, wRref(F2) = 0.1228, T = 293(2) K. [ABSTRACT FROM AUTHOR]

In the current work, dependent density functional theory and time-dependent density functional theory calculations coupled with the inherent charge hopping model and some visualization techniques have been used to systematically investigate the photovoltaic properties of PC61BM-PDPP5T system. Calculations show that PC61BM-PDPP5T system possesses the relatively large open-circuit voltage 0.82 V the middle-sized exciton binding energy (0.690 eV), the small internal reorganization energy (0.159 eV) in the exciton-dissociation process, but the relatively large one (0.396 eV) in the case of charge-recombination. With a simplified molecular model, the exciton-dissociation rate constant, kdis, is estimated to be as large as 1.156 × 1010 s−1 in PC61BM-PDPP5T phase interface, while the charge-recombination one, krec, is only 1.018 × 107 s−1 under the same condition, which indicates a rapid and efficient photoinduced exciton-dissociation process. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]