The variations in the cyclometalating ligand structure give rise to rich photophysics of the complexes obtained. It was found that the orbitals of both N^C and N^N ligands make a major contribution to the formation of emissive excited states and a delicate balance between the energy of the ligands' frontier orbitals determines the emission character.As a prototype for the catalytic oxidation of organic contaminants, photocatalytic methanol dissociation on rutile TiO2(110) has drawn much attention, but its reaction mechanism remains elusive. While polarons are ubiquitous in photovoltaics and heterogeneous catalysis, how surface polarons influence adsorption remains unclear. In this paper, density functional theory is used to study the effect of excess electrons and holes on methanol dissociation on rutile TiO2(110). The effect of excess carriers for three types of methanol dissociation on the metal oxides are compared. The results show that the excess electron and hole play different roles in the dissociation reactions even though they present similar adsorption behaviors. The excess electron is easily trapped in the lattice Ti atom, and it decreases the dissociation barrier of methanol to 0.13 eV. Furthermore, the excess hole prefers to stick with the hydroxyl radical, which increases the energy barrier of methanol dissociation up to 0.43 eV. It was found that the height of the dissociation barrier is dependent on the orientation of the methanol molecules, not on the distance to the modified electron. This study identifies the essential roles of excess electrons and holes for promoting O-H dissociation. Our findings contribute considerably to broadening the understanding of photocatalytic chemistry.A near-infrared two-photon fluorescent probe (TAN) was synthesized for selective detection and deep-depth imaging of NO in lipid droplets. All results demonstrated that NO production in lipid droplets is closely correlated with the resistance to anti-tumor drugs, and NO inhibitors can effectively improve the efficacy of chemotherapeutic agents.A fluorinated, thulium(iii) complex (Tm-PFZ-1) serves as an off-on 19F magnetic resonance probe for Zn(ii). Rapid exchange among different conformations combined with paramagnetic relaxation and chemical shift effects of Tm(iii) effectively eliminate the 19F NMR/MRI signal in Tm-PFZ-1. Chelation of Zn(ii) induces increased structural rigidity and reduces exchange rate, affording a robust 19F NMR/MRI signal. Tm-PFZ-1 represents a first-in-class paramagnetic 19F MR agent that exploits a novel sensing mechanism for Zn(ii) and is the first 19F MR-based scaffold to provide an "off-on" response to Zn(ii) in aqueous solution.Single particle imaging of upconversion nanoparticles (UCNPs) has typically been realized using hexagonal (β) phase lanthanide-doped sodium yttrium fluoride (NaYF4) materials, the upconversion luminescence (UCL) of which saturates at power densities (P) of several hundred W cm-2 under 980 nm near-infrared (NIR) excitation. Cubic (α) phase UCNPs have been mostly neglected because of their commonly observed lower UCL efficiency at comparable P in ensemble level studies. https://www.selleckchem.com/products/cc-885.html Here, we describe a set of sub-15 nm ytterbium-enriched α-NaYbF4Er3+@CaF2 core/shell UCNPs doped with varying Er3+ concentrations (5-25%), studied over a wide P range of ∼8-105 W cm-2, which emit intense UCL even at a low P of 10 W cm-2 and also saturate at relatively low P. The highest upconversion quantum yield (ΦUC) and the highest particle brightness were obtained for an Er3+ dopant concentration of 12%, reaching the highest ΦUC of 0.77% at a saturation power density (Psat) of 110 W cm-2. These 12%Er3+-doped core/shell UCNPs were also the brightest UCNPs among this series under microscopic conditions at high P of ∼102-105 W cm-2 as demonstrated by imaging studies at the single particle level. Our results underline the potential applicability of the described sub-15 nm cubic-phase core/shell UCNPs for ensemble- and single particle-level bioimaging.This paper proposes microfluidic particle separation by sheath-free deterministic lateral displacement (DLD) with inertial focusing in a single straight input channel. Unlike conventional DLD devices for size-based particle separation, in which sheath streams are used to focus the particles before the solution containing them reaches the DLD arrays, the proposed method uses inertial focusing to align the particles along the middle or the sidewalls of the straight rectangular input channel. The two-stage model of inertial focusing is applied to reduce the length of the side-focusing channel. The proposed method is demonstrated by using it to separate fluorescent polymer particles of diameters 13 and 7 μm, in the process of which the effect of the particle focusing regime on the separation performance is also investigated. Through middle focusing, the method is further used to separate MCF-7 cells (a model of circulating tumor cells (CTCs)) and blood cells, with ∼99.0% capture efficiency achieved.Switchable trans-cis isomerization of azobenzene (AB) and its derivatives on metallic surfaces have offered rich possibilities to functionalize molecular devices. However, the lack of a good understanding of the isomerization pathway has severely limited our ability for rational design. One of the long-debated issues is the cis configuration of the parental AB on the Au(111) surface, for which the experimentally inferred structure differs from the theoretically predicted global minimum. Here, we theoretically identify a new in situ metastable configuration for cis-AB on Au(111) that can reproduce all the observations reported in the scanning tunneling microscopy experiments. It reveals that the bistability of AB on the Au(111) surface is attributed to the significantly increased kinetic stability of the newly discovered cis-AB isomer. A fascinating tumbling pathway that overcomes two energy barriers stimulated by tunneling electrons for the trans-cis AB isomerization on Au(111) has been verified, suggesting a new type of molecular motion based on the AB systems.Wetting state transition regulated by surface roughness has increasing importance for its wide applications. Molecular dynamics simulations have been performed to study the wetting state transition induced by surface roughness in the gallium-carbon system. There is a transition from the Wenzel state to the Cassie state when the roughness is changed. When the surface roughness is more than 1.8, the gallium droplet is in a Cassie state, but when it is less than 1.6, it is in the Wenzel state. The substrate composed of irregular pillars has a similar effect on the wetting state transition. Besides, distinctive variations occur in the interface tension, the mean-squared displacement, the wetted surface and the interaction energy as the wetting state changes, which are further explained by the proposed model. This study would provide significant guidance for designing superhydrophobic surfaces in the future.