X‐ray structures,spectroscopic, electrochemical,thermal, antibacterial,and DFT studies of two nickel(II) and cobalt(III) complexes constructed from a new quinazoline‐type ligand

Two two‐dimensional supramolecular Nickel(II) and Cobalt(III) complexes, [Ni( L ² )₂]·2CH₃OH ( 1 ) and [2Co( L ² )₂] ( 2 ) ( HL ²  = 1‐(2‐{[(E)‐3‐bromo‐5‐chloro‐2‐hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of salts acetate with HL ¹ (2‐(3‐bromo‐5‐chloro‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide, H is the deprotonatable hydrogen). During the reaction, the C–N bond in HL ¹ is converted into the C=N–OH group in HL ² . The spectroscopic data of both complexes were compared with the ligand HL ¹ . HL ¹ and both complexes were determined by single‐crystal X‐ray crystallography. The differently geometric features of the obtained complexes 1 and 2 are observed. In the crystal structure, 1 and 2 form an infinite 1‐D chain‐like and 2‐D supramolecular frameworks. EPR spectroscopy of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. In addition, the calculated HOMO and LUMO energies show the character of HL ¹ , complexes 1 and 2 . The electronic transitions and spectral features of HL ¹ and both complexes were discussed by TD‐DFT calculations.     

Co(III)/Zn(II)-catalyzed dearomatization of indoles and coupling with carbenes from ene-yne ketones via intramolecular cyclopropanation

A straightforward and efficient protocol for dearomatizing indoles is described. The reaction, catalyzed by an inexpensive Co(III)/Zn(II) catalyst, starts from easily accessible N-pyrimidinyl indoles and ene-yne ketones. Mild reaction conditions, high diastereoselectivity, a broad substrate scope, effective functional group tolerance, and reasonable to remarkable yields were observed.     

Spin–Spin Coupling Between Two meta-Benzyne Moieties In a Quinolinium Tetraradical Cation Increases Their Reactivities

The reactivity of a carbon-centered σ,σ,σ,σ-type singlet-ground-state tetraradical containing two meta-benzyne moieties was examined in the gas phase. Surprisingly, the tetraradical showed higher reactivity than its individual meta-benzyne counterparts. The reactivity of meta-benzynes is controlled by their (calculated) distortion energy ΔE_2.3, singlet–triplet spitting ΔE_S–T, and electron affinity (EA_2.3) of the meta-benzyne moiety at the transition state geometry for hydrogen-atom abstraction reactions. The addition of a second meta-benzyne moiety to a meta-benzyne does not significantly change EA_2.3. However, ΔE_2.3 is substantially decreased for both meta-benzyne moieties in the tetraradical, and this explains their higher reactivities. The decrease in ΔE_2.3 for each meta-benzyne moiety in the tetraradical is rationalized by stabilizing spin–spin coupling between one radical site in each meta-benzyne moiety. Therefore, spin–spin coupling between the meta-benzyne moieties in this tetraradical increases its reactivity, whereas spin–spin coupling within each meta-benzyne moiety decreases its reactivity.     

Synthesis and characterization of a trefoil-shaped liquid crystal based on 1,3,5-triazine with carbazole groups

A trefoil-shaped liquid crystal containing an aromatic hetero-nucleus has been synthesized by the reaction of cyanuric chloride with 3,6-didecanoyl carbazole (DDC). The molecular structure was characterized by ¹H NMR and ¹³C NMR spectroscopy, mass spectroscopy and elemental analysis. The core consists of 1,3,5-triazine directly linked to three carbazole groups. The trefoil-shaped conformation is suggested by molecular modelling. The mesophase was investigated using DSC, X-ray diffraction and polarizing optical microscopy. The X-ray diffraction pattern of a sample cooled slowly from the isotropic state showed sharp peaks in the small angle and wide angle regions implying the existence of a columnar phase with interand intra-columnar ordering. An unusual reticular texture similar to a cholesteric texture was observed.     

The influence of dielectric layer on the thermal boundary resistance of GaN-on-diamond substrate

The cooling behavior of GaN-on-diamond substrate can be enhanced by reducing the thermal boundary resistance (TBR), which is mainly determined by the nature of interlayer. Although SiN film is considered as the primary candidate of dielectric layer, it is still needed to be optimized. In order to facilitate the understanding of the influence of dielectric layer on the TBR of GaN-on-Diamond substrate, aluminum nitride (AlN), and silicon nitride (SiN) film were compared systematically, both of which are 100 nm. The time-domain thermoreflectance (TDTR) measurements, adhesion evaluation, and microstructural analysis methods were adopted to analyse these two interlayers. The results show the TBR of SiN interlayer is as low as 38.5 ± 2.4 m²K GW⁻¹, comparing with the value of 56.4 ± 5.5 m²K GW⁻¹ for AlN interlayer. The difference of TBR between these two interlayers is elucidated by the diamond nucleation density, and the adhesion between the diamond film and GaN substrate, both of which are affected by the surface charge and chemical groups of the dielectric layer.     

Calculation of the light intensity distribution reflected by a planar corner-cube retroreflector array with the size of centimeter and above

The light intensity distribution (LID) reflected by a planar corner-cube retroreflector array with the size of centimeter and above (PCCRA) is calculated based on the Collins formula, coordinate transformation matrixes and vector algebra. The expression can be used for the PCCRAs with different parameters and different complex optical systems described by ABCD matrix. The expression indicates that the LID of a PCCRA is much different from a single corner-cube retroreflector (CCR) with equivalent aperture. Computer simulations are applied to explain the expression clearly. The results show that the LID of the PCCRA is more homogeneous than the single CCR with equivalent aperture under circumstances of both normal incident light and oblique incident light. In addition, the expression is proved by comparing the simulation result of the PCCRA only comprising a single CCR and the previous experimental result.     

镍-磷/纳米碳管化学复合镀层的研究

采用化学复合镀方法,在基体铜片上进行Ni-P／纳米碳管复合镀．用金相显微镜、扫描电子显微镜、X射线衍射仪和显微硬度计等实验手段研究复合镀层的组织、结构和性能．结果表明:随着镀液中纳米碳管含量的增加,复合镀层表面的颗粒变小且密度增加;复合镀层的硬度随纳米碳管含量的增加而提高;此外,纳米碳管的加入,使镀层由非晶变成了纳米晶,促进了复合镀层的晶化．     

An investigation on dysphotopsia of a sigma-edged intraocular lens

A sigma-edged design of intraocular lens (IOL) is proposed to minimize the reflected glare images associated with the edge. The optimal sigma inverse edge is investigated when pupil diameter is 5.0 mm by the established Escudero-Sanz's wide angle model. The non-sequential ray tracing program of Zemax-EE (Zemax Development Corp., San Diego, USA) is used to investigate the sigma edge of reducing the potential for edge glare phenomena. The results show that sigma-edged design can significantly reduce the reflected glare intensity on retina if the angle of its inverse edge is taken from 20 to 70 degrees.