Why Does <i>trans</i>-Azobenzene Have a Smaller Isomerization Yield for ππ* Excitation Than for nπ* Excitation?

A realistic dynamics simulation study is reported for the photoisomerization of trans-azobenzene. The isomerization follows both nπ* (the HOMO → LUMO) and ππ* (the HOMO−1 → LUMO) excitations. The simulation finds that for the ππ* excitation, the relaxation of the S(ππ*) state is immediately followed by double excitation, (π)2(π*)2. The decay from the S((π)2(π*)2) state to the S0 state can occur at partially twisted structure, which favors the formation of the trans isomer. Multiple decay channels are found at about twisted structure for both nπ* and ππ* excitations. Decay at about twisted geometry leads to the formation of either cis or trans isomer. Opening of the decay channel at partially twisted structure accounts for the smaller isomerization yield for the ππ* excitation

Why Does <i>trans</i>-Azobenzene Have a Smaller Isomerization Yield for ππ* Excitation Than for nπ* Excitation?

A realistic dynamics simulation study is reported for the photoisomerization of trans-azobenzene. The isomerization follows both nπ* (the HOMO → LUMO) and ππ* (the HOMO−1 → LUMO) excitations. The simulation finds that for the ππ* excitation, the relaxation of the S(ππ*) state is immediately followed by double excitation, (π)2(π*)2. The decay from the S((π)2(π*)2) state to the S0 state can occur at partially twisted structure, which favors the formation of the trans isomer. Multiple decay channels are found at about twisted structure for both nπ* and ππ* excitations. Decay at about twisted geometry leads to the formation of either cis or trans isomer. Opening of the decay channel at partially twisted structure accounts for the smaller isomerization yield for the ππ* excitation

Why Does <i>trans</i>-Azobenzene Have a Smaller Isomerization Yield for ππ* Excitation Than for nπ* Excitation?

A realistic dynamics simulation study is reported for the photoisomerization of trans-azobenzene. The isomerization follows both nπ* (the HOMO → LUMO) and ππ* (the HOMO−1 → LUMO) excitations. The simulation finds that for the ππ* excitation, the relaxation of the S(ππ*) state is immediately followed by double excitation, (π)2(π*)2. The decay from the S((π)2(π*)2) state to the S0 state can occur at partially twisted structure, which favors the formation of the trans isomer. Multiple decay channels are found at about twisted structure for both nπ* and ππ* excitations. Decay at about twisted geometry leads to the formation of either cis or trans isomer. Opening of the decay channel at partially twisted structure accounts for the smaller isomerization yield for the ππ* excitation

Why Does <i>trans</i>-Azobenzene Have a Smaller Isomerization Yield for ππ* Excitation Than for nπ* Excitation?

A realistic dynamics simulation study is reported for the photoisomerization of trans-azobenzene. The isomerization follows both nπ* (the HOMO → LUMO) and ππ* (the HOMO−1 → LUMO) excitations. The simulation finds that for the ππ* excitation, the relaxation of the S(ππ*) state is immediately followed by double excitation, (π)2(π*)2. The decay from the S((π)2(π*)2) state to the S0 state can occur at partially twisted structure, which favors the formation of the trans isomer. Multiple decay channels are found at about twisted structure for both nπ* and ππ* excitations. Decay at about twisted geometry leads to the formation of either cis or trans isomer. Opening of the decay channel at partially twisted structure accounts for the smaller isomerization yield for the ππ* excitation

From Two-Dimensional Double Decker Architecture to Three-Dimensional <i>pcu</i> Framework with One-Dimensional Tube: Syntheses, Structures, Luminescence, and Magnetic Studies

The hydrothermal reactions of lanthanide salts with substituted imidazole-4,5-dicarboxylic acids in the presence of aliphatic carboxylates afforded a new family of lanthanide metal–organic frameworks formulated as {Y₃[(Heimda)₄(μ₂-HCOO)·3H₂O]·H₂O}_<i>n</i> (<b>1</b>Y), {[Gd₃(Heimda)₄(μ₂-HCOO)·4H₂O]·2H₂O}_<i>n</i> (<b>2</b>Gd), {[Tb₃(Heimda)₄(μ₂-HCOO)·4H₂O]·2H₂O}_<i>n</i> (<b>3</b>Tb) and {[Nd₃(Hpimda)₂(μ₂-HCOO) (μ₂ -C₂O₄)₂·6H₂O]·4H₂O}_<i>n</i> (<b>4</b>Nd), (H₃eimda = 2-ethyl-1<i>H</i>-imidazole-4,5-dicarboxylic acid, while H₃pimda = 2-propyl-1<i>H</i>-imidazole-4,5-dicarboxylic acid). The structural diversity and photophysical and magnetic properties have been investigated. The polymer <b>3</b> triggers intense characteristic lanthanide-centered green luminescence under UV excitation, and it exhibits gradually increasing luminescence intensities when dispersed in water, ethanol, and DMSO as suspensions. After water molecules are liberated from the condensed frameworks of <b>4</b>, the evacuated product (<b>4a</b>) exhibits nitrogen sorption properties at 77 K with a hysteresis, as well as strong characteristic emissions of the Nd­(III) ion in the near-infrared (NIR) region. Polymer <b>2</b> displays very weak but significant ferromagnetic couplings between adjacent Gd­(III) ions through the carboxylate bridging, whereas the depopulation of the Stark levels or possible antiferromagnetic interactions within both polymers <b>4</b> and <b>4a</b> leads to a continuous decrease of χ_M<i>T</i> when the samples are cooled from 300 to 2 K

Table_1_The value of CT radiomic in differentiating mycoplasma pneumoniae pneumonia from streptococcus pneumoniae pneumonia with similar consolidation in children under 5 years.docx

ObjectiveTo investigate the value of CT radiomics in the differentiation of mycoplasma pneumoniae pneumonia (MPP) from streptococcus pneumoniae pneumonia (SPP) with similar CT manifestations in children under 5 years.MethodsA total of 102 children with MPP (n = 52) or SPP (n = 50) with similar consolidation and surrounding halo on CT images in Qilu Hospital and Qilu Children’s Hospital between January 2017 and March 2022 were enrolled in the retrospective study. Radiomic features of the both lesions on plain CT images were extracted including the consolidation part of the pneumonia or both consolidation and surrounding halo area which were respectively delineated at region of interest (ROI) areas on the maximum axial image. The training cohort (n = 71) and the validation cohort (n = 31) were established by stratified random sampling at a ratio of 7:3. By means of variance threshold, the effective radiomics features, SelectKBest and least absolute shrinkage and selection operator (LASSO) regression method were employed for feature selection and combined to calculate the radiomics score (Rad-score). Six classifiers, including k-nearest neighbor (KNN), support vector machine (SVM), extreme gradient boosting (XGBoost), random forest (RF), logistic regression (LR), and decision tree (DT) were used to construct the models based on radiomic features. The diagnostic performance of these models and the radiomic nomogram was estimated and compared using the area under the receiver operating characteristic (ROC) curve (AUC), and the decision curve analysis (DCA) was used to evaluate which model achieved the most net benefit.ResultsRF outperformed other classifiers and was selected as the backbone in the classifier with the consolidation + the surrounding halo was taken as ROI to differentiate MPP from SPP in validation cohort. The AUC value of MPP in validation cohort was 0.822, the sensitivity and specificity were 0.81 and 0.81, respectively.ConclusionThe RF model has the best classification efficiency in the identification of MPP from SPP in children, and the ROI with both consolidation and surrounding halo is most suitable for the delineation.</p

A Series of Lanthanide−Organic Frameworks Based on 2-Propyl-1H-imidazole-4,5-dicarboxylate and Oxalate: Syntheses, Structures, Luminescence, and Magnetic Properties

A family of self-assembly lanthanide−organic coordination polymers with both rigid and flexible ligands formulated as {[Ln2(Hpimda)2(μ4-C2O4)·2H2O]·4H2O}n (Ln = Sm (1), Eu (2), Tb (3), Dy (4), Ho (5), Er (6), H3pimda = 2-propyl-1H-imidazole-4,5-dicarboxylic acid) has been synthesized from the reactions of H3pimda with trivalent lanthanide salts in the presence of oxalate as coligand. X-ray diffraction analysis reveals that these complexes are isomorphous and isostructural, and each forms a novel three-dimensional (3D) frameworks structure, in which the metalloligands' two-dimensional (2D) networks were constructed from the lanthanide ion, 2-propyl-imidazole-dicarboxylate as well as oxalate ligands, and the oxalate further acts as a pillar to link the [Ln(Pimda)(oxo)] 2D grids to generate the 3D open frameworks, leaving one-dimensional channels, which are occupied by water clusters displaying an intricate array. The luminescence emission spectra of the complexes vary depending on which lanthanide ion is present. In addition, compounds 3, 4, and 5 exhibited weak but significant ferromagnetic couplings within the two adjacent magnetic centers bridged through oxalato, whereas dominant antiferromagnetic interaction was observed in the erbium compound of 6, respectively