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Abstract A non-destructive test method of a small defect (a dust particle or an air bubble) in a strongly confined planar waveguide is demonstrated in this work. Based on strong resonances between the small defect and some special incident wavelengths, an accurate reconstruction of the defect parameters can quickly be obtained from our previous numerical method. An example is given to verify the validity of the present measurement method. 相似文献
154.
Dr. Zhenghai Yang Dr. Srinivas Doddipatla Dr. Chao He Vladislav S. Krasnoukhov Prof. Dr. Valeriy N. Azyazov Prof. Dr. Alexander M. Mebel Prof. Dr. Ralf I. Kaiser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13584-13589
The silene molecule (H2SiCH2; X1A1) has been synthesized under single collision conditions via the bimolecular gas phase reaction of ground state methylidyne radicals (CH) with silane (SiH4). Exploiting crossed molecular beams experiments augmented by high-level electronic structure calculations, the elementary reaction commenced on the doublet surface through a barrierless insertion of the methylidyne radical into a silicon-hydrogen bond forming the silylmethyl (CH2SiH3; X2A′) complex followed by hydrogen migration to the methylsilyl radical (SiH2CH3; X2A′). Both silylmethyl and methylsilyl intermediates undergo unimolecular hydrogen loss to silene (H2SiCH2; X1A1). The exploration of the elementary reaction of methylidyne with silane delivers a unique view at the widely uncharted reaction dynamics and isomerization processes of the carbon–silicon system in the gas phase, which are noticeably different from those of the isovalent carbon system thus contributing to our knowledge on carbon silicon bond couplings at the molecular level. 相似文献
155.
Dr. Todor Baramov Bianca Schmid Ho Ryu Jinhoon Jeong Dr. Karlijn Keijzer Dr. Leonard von Eckardstein Prof. Dr. Mu-Hyun Baik Prof. Dr. Roderich D. Süssmuth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(28):6955-6962
The E. coli siderophore enterobactin, the strongest FeIII chelator known to date, forms hexacoordinate complexes with SiIV, GeIV, and TiIV. Synthetic protocols have been developed to prepare non-symmetric enterobactin analogues with varying denticities. Various benzoic acid residues were coupled to the macrocyclic lactone to afford a diverse library of ligands. These enterobactin analogues were bound to SiIV, GeIV, and TiIV, and the complexes were investigated through experimental and computational techniques. The binding behavior of the synthesized chelators enabled assessment of the contribution of each of the phenolic hydroxy groups in enterobactin to metal-ion complexation. It was found that at least four O-donors are needed for enterobactin derivatives to act as metal binders. Density functional theory calculations indicate that the strong binding behavior of enterobactin can be ascribed to a diminished translational entropy penalty, a common feature of the chelate effect, coupled with the structural arrangement of the three catechol moieties, which allows the triseryl base to be installed without distorting the preferred local metal-binding geometry of the catecholate ligands. 相似文献
156.
A method to generate NOON states with three photons by injecting photons in an array of three waveguides is presented. Conditional measurements project the wave function in a given (desired) state. In passing, it is shown how the array of three waveguides, that effectively reproduces the interaction of three fields, may be reduced to the interaction of two fields. 相似文献
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《Mendeleev Communications》2022,32(1):16-18
The synthesis of modified neutral bis-NHI (NHI is N-heterocyclic imine) ligands and their application for the stabilization of tetryliumylidenes are reported. The ligands’ scaffolding consists of either saturated or methylated imidazoline backbones, and the bridge alternated from flexible ethylene to more rigid o-phenylene. Transmetalation reactivity of the cationic SnII compounds was tested towards LiAlH4 and IDipp→SiCl2 [IDipp is 1,3-bis(2,6-diisopropyl- phenyl)imidazol-2-ylidene] affording the respective aluminium and silicon complexes. 相似文献
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Two silylene‐spaced ((E)‐vinylsilyl)anthracene‐dipyrromethane dyads have been designed and synthesized by RhCl(PPh3)3‐catalyzed hydrosilylation reactions of 5‐methyl‐5′‐(ethynylaryl)dipyrromethanes with (9‐Anthryl)‐dimethylsilane. The complexation studies of dyads toward different anions have also been performed, which reveal that dyads exhibit a highly selective response towards fluoride anion attributable to both hydrogen‐bonding and pentacoordination phenomena. This dual‐mode fluoride recognition event is unprecedented and may pave the way for future developments in the areas of porphyrinoids, organosilicon, polymer, and supramolecular chemistry. 相似文献