Electron momentum spectroscopy of CF2Cl2: experimental and theoretical momentum profiles for outer valence orbitals

Electron momentum distributions for outer valence orbitals of CF2Cl2 have been obtained by (e,2e) electron momentum spectroscopy at an incident energy of 1200 eV + binding energy. The experimental electron momentum profiles are compared with Hartree-Fock and density functional theory (DFT) calculations using B3LYP hybrid functional with the 6-31G and 6-311+G* basis sets. Generally, the shapes of the experimental momentum profiles are well reproduced by DFT calculations using larger basis sets 6-311 + G*. An attempt has been made to clarify the ordering of the outer valence orbitals, which have been in controversy, by comparing experimental results with B3LYP/6-311 + G* calculations.     

On perturbation bounds for orthogonal projections

In this paper, we present some new perturbation bounds for the orthogonal projections onto the column and row spaces of a matrix, which improve some existing results. Numerical examples are presented to illustrate our results.     

One-pot ligation strategy for atypical ubiquitin chains synthesis by using the trifluoroacetamidomethyl-protected isopeptide-linked Ub (Tfacm-isoUb) unit

Protein chemical synthesis can provide the homogeneous atypical ubiquitin chains that are usually difficult to obtain by other methods. Herein, we report a new one-pot ligation approach for the synthesis of atypical Ub chains based on the Tfacm-protected isoUb building block with operational simplicity and high efficiency. The key intermediate, the Tfacm-protected isoUb building block can be readily prepared by Fmoc SPPS. The practicality and efficiency of the new method is demonstrated by the successful preparation of K11-linked di-Ub.     

Observation of capillary discharge Ne-like Ar 46.9?nm laser with pre-pulse and main-pulse delay time in the domain of 2–130?μs

We demonstrated the lasing of Ne-like Ar 46.9?nm pumped by capillary discharge with the delay time between pre-pulse and main-pulse ranging from 2 to 130???s. Results show that the laser output reduced significantly when the delay time is much longer than 12???s. The temporal evolution of spontaneous radiation emitted from pre-ionized plasma implies that the observed reduction of the laser output is caused by the axial non-uniformity of pre-ionized plasma density and the decrease of pre-ionized plasma density.     

A 3D Luminescent Metal‐organic Framework Constructed from Cu4I4 Cubane Clusters and Triangular Imidazole Ligand

Abstract . The solvothermal reaction between cuprous iodide and the rigid triangular imidazole ligand in mixed N,N′‐dimethylacetamide (DMA)‐acetonitrile solvent leads to the isolation of the 3D metal‐organic framework [(Cu₄I₄)₃(TIPA)₄] · 7DMA ( 1 ) [TIPA = tri(4‐imidazolylphenyl) amine], which was characterized by elemental analysis, IR spectroscopy, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Topologically, the structure of 1 is an unprecedented 3,3,4,4‐connected net with a point symbol of {4.8.10}₂{4.8²}₂{4².8².10²}₂{8⁴.12²}. Compound 1 exhibits orange‐red photoluminescence with an emission maximum at 622 nm at room temperature.