Reversible Transformation and Distribution Determination of Diverse Pt Single-Atom Species.

In single-atom catalysts (SACs), the complexity of the support anchoring sites creates a vast diversity of single-atom species with varied coordination environments. To date, the quantitative distribution of these diverse single-atom species in a given SAC has remained elusive. Recently, CeO2-supported metal SACs have been extensively studied by modulating their local environments via numerous synthetic strategies. However, owing to the absence of a quantitative description, unraveling the site-specific reactivity and regulating their transformation remain challenging. Here, we show that two distinct Pt/CeO2 SACs can be reversibly generated by oxidative and nonoxidative dispersions, which contain varied Pt1On-Ceδ+ single-atom species despite similar Pt charge states and coordination numbers. By means of Raman spectroscopy and computational studies, we semiquantitatively reveal the distribution of diverse Pt1On-Ceδ+ species in each specific SACs. Remarkably, the minority species of Pt1O4-Ce3+-Ov accounting for only 14.2% affords the highest site-specific reactivity for low-temperature CO oxidation among the other abundant counterparts, i.e., Pt1O4-Ce4+ and Pt1O6-Ce4+. The second nearest oxygen vacancy (Ov) not only acts synergistically with the nearby active metal sites to lower the reaction barrier but also facilitates the dynamic transformation from six-coordinated to four-coordinated sites during cyclic nonoxidative and oxidative dispersions. This work elucidates the quantitative distribution and dynamic transformation of varied single-atom species in a given SAC, offering a more intrinsic descriptor and quantitative measure to depict the inhomogeneity of SACs.

1-Chloro-methyl-1H-1,2,3-benzotriazole.

In the title compound, C(7)H(6)ClN(3), the benzotriazole ring is essentially planar with a maximum deviation of 0.0110 (15)Å, and makes a dihedral angle of 0.46 (8)° with the benzene ring. In the crystal, mol-ecules are linked through inter-molecular C-H⋯N hydrogen bonds, forming chains along the c axis.

[µ-1,1'-(Butane-1,4-di-yl)di-1H-benz-imidazole-κN:N]bis-{[N,N'-bis(car-boxy-meth-yl)ethyl-enediamine-N,N'-di-acetato-κO,O',O'',N,N']mercury(II)} methanol disolvate.

The binuclear title complex, [Hg(2)(C(10)H(14)N(2)O(8))(2)(C(18)H(18)N(4))]·2CH(3)OH, lies on an inversion center with the unique Hg(II) ion coordinated in a disorted octa-hedral environment with one Hg-N bond significantly shorter than the other two. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link complex and solvent mol-ecules into a three-dimensional network.

{4-Bromo-2-[2-(piperidin-1-ium-1yl)ethyl-iminometh-yl]phenolato}diiodido-zinc(II).

In the title complex, [ZnI(2)(C(14)H(19)BrN(2)O)], the Zn(II) atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetra-hedral coordination. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains running along the b axis.

Diiodido[N'-(2-methoxy-benzyl-idene)-N,N-dimethyl-ethane-1,2-diamine]zinc(II).

In the title complex, [Zn(C(12)H(18)N(2)O)I(2)], the Zn(II) ion is four-coordinated by the imine N and amine N atoms of the Schiff base ligand and by two iodide ions in a distorted tetra-hedral coordination.

{4-Bromo-2-[3-(diethyl-ammonio)propyl-imino-meth-yl]phenolato}diiodidozinc(II) methanol solvate.

In the title complex, [ZnI(2)(C(14)H(21)BrN(2)O)]·CH(3)OH, the asymmetric unit consists of a mononuclear zinc(II) complex mol-ecule and a methanol solvent mol-ecule. The compound was derived from the zwitterionic form of the Schiff base 4-bromo-2-[3-(diethyl-amino)propyl-imino-meth-yl]phenol. The Zn(II) atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand and by two iodide ions in a distorted tetra-hedral coordination. In the crystal structure, the methanol mol-ecules are linked to the Schiff base mol-ecules through N-H⋯O and O-H⋯O hydrogen bonds. One I atom is disordered over two positions in a 0.702 (19):0.298 (19) ratio.

Diiodido{4-nitro-2-[2-(piperidin-1-yl)ethyl-imino-meth-yl]phenolato}zinc(II).

In the title complex, [ZnI(2)(C(14)H(19)N(3)O(3))], the Zn(II) atom is four-coordinated by the imine N and phenolate O atoms of the Schiff base ligand, and by two iodide ions in a distorted tetra-hedral coordination. In the crystal structure, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming dimers.

[Determination of solubility parameter for dicationic ionic liquid by inverse gas chromatography].

An inverse gas chromatographic method has been used to measure the solubility parameter of the dicationic ionic liquid, 1,10-bis(3-methylimidazolium-1-yl) decane hexafluorophosphate [C10(MIM)2][PF6]2, at the absolute temperatures from 343.15 K to 363.15 K. The test probe solvents were n-octane, n-dodecane, n-tetradecane, and n-hexadecane. The specific retention volumes of the solvents (Vg(0)), the molar enthalpy of sorption (DeltaH1(S)), the partial molar enthalpy of mixing at infinite dilution (DeltaH1(infinity)), the molar enthalpy of vaporization (DeltaHv), the activity coefficients at infinite dilution (gamma12(infinity)), Flory-Huggins interaction parameters (chi12(infinity)) between [C10(MIM)][PF6]2 and probe solvents were obtained. parameter (delta2) of [C10(MIM)2][PF6]2 was determined as 15.01 (J x cm(-3))(1/2), which was of great importance to the study of the solution behavior and application for ionic liquid.