Photochemical Reaction of Benzoin Caged Compound： Time-Resolved Fourier Transform Infrared Spectroscopy Study

The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.

Parameters identification of the compound cage rotor induction machine based on linearized Kalman filtering

A mathematical model has been built up for compound cage rotor induction machine with the rotor resistance and leakage inductance in the model identified through Kalman filtering method. Using the identified parameters, simulation studies are performed, and simulation results are compared with testing results.

Synthesis of two new cage molecules containing trinitromethyl group

Two new cage compounds,4-trinitroethyl-10-nitro-2,6,8,12-tetraacetylhexaazaisowurtzitane（3） and 4-trinitroethyl- 2,6,8,10,12-pentanitrohexaazaisowurtzitane（4）,containing trinitromethyl group were synthesized by a novel method,and their structures were confirmed by IR,;H NMR,MS and single crystal X-ray.DSC result shows that compound 4 has surprising thermal stability and could be a potential energetic compound.

A Photocaged Azidosugar for Light-Controlled Metabolic Labeling of Cell-Surface Sialoglycans

The photocaging strategy has been widely used for activating biomolecules and hence regulating the underlying biological processes with high temporal and spatial resolution.Herein,we integrate this strategy into metabolic glycan labeling,which enables optical-ly-controlled metabolic labeling of cell-surface sialoglycans with azides.N-Azidoacetylmannosamine(ManNAz)is caged with a 4,5-dimethoxy-2-nitrobenzyl(DMNB)group at the anomeric hydroxyl group to block its cellular metabolism.After feeding to the cells,irradiation with 365 nm UV light or 405 nm visible light cleaves the photocage and generates ManNAz within the cells.ManNAz is metabolically converted to azido sialic acid,which is then incorporated into cell-surface sialoglycans.We demonstrated spatial and temporal control of this strategy by specifically labeling sialoglycans on a single cell and tracking the metabolism of ManNAz based on light-triggered pulse-chase labeling,respectively.The light-controlled metabolic glycan labeling strategy should facilitate probing of glycosylation in complex biological systems with high spatiotemporal precision.

A New Polynitrogen-Heterocyclic Scaffold 2,4,6,8-Tetraazanoradamantane Skeleton:Synthesis and Conversion of Its Functionalities

Comprehensive Summary 2,4,6,8-Tetraazanoradamantane skeleton is a unique rigid cage-like organic structure that has not been established.In this article,a facile protocol to build all-bridge-position-functionalized 2,4,6,8-tetraazanoradamantane skeleton by condensation of glyoxal,primary amines and disubstituted malondialdehydes,which were in situ generated from 2,2-dipropenyl-1,3-dioxolane or 4,4-dimethoxyhepta-2,5-diene via ozonation,is reported for the first time.A variety of primary amines are compatible with this process,and the corresponding 2,4,6,8-tetraalkyl-2,4,6,8-tetraazanoradamantane-9-one ethylene or methyl ketals were achieved in 16%—58%yields.N-Benzyl group could be converted to other functionalities such as acetyl and nitro,which indicates the structural diversity of this scaffold.

A stable biocompatible porous coordination cage promotes in vivo liver tumor inhibition

Many emerging strategies in chemo-,gene-,and immunotherapy require the accumulation of reagents in the cell nucleus.However,their delivery into the nucleus is often limited.Nuclear delivery could be enhanced with a rationally designed cargo-delivery scaffold,but this approach has rarely been successfully implemented.Herein,a stable,biocompatible molecular capsule that encapsulates and delivers camptothecin,a DNA topoisomerase I inhibitor,into the nucleus of living cells was reported.Nuclear delivery is facilitated by the ultra-small diameter,zero net charge,and hydrophobicity of the capsule.The encapsulated drug complex displays superior toxicity towards multiple cancer cells over the free drug,the Food and Drug Administration(FDA)approved drugs,as well as conventionally reported drug vectors.Additionally,it inhibits liver cancer tumor growth in a xenograft mouse model.Modification of the properties of such molecular capsules may make it possible to design therapeutic strategies that target specific cell organelles.

Intra-Ring Bridging:A Strategy for Molecular Design of Highly Energetic Nitramines

Main observation and conclusion Important progress has been made in the development of energetic molecules with high performance by computer-aided molecular design in recent years,but structural novelty of organic scaffolds is insufficient.In this work,we propose an intra-ring bridging strategy inspired by the known energetic nitramines to design novel polycyclic and cage energetic molecules.More than 100 energetic structures were designed by introducing the C—C bridges and increasing the ring size.The synthesis difficulty is considered besides the two most concerned properties of EMs,energy and safety.After a comprehensive estimation,a symmetric cage molecule labeled as 8U-30 was finally selected because of its relatively high detonation performance,and comparable impact sensitivity as well as synthetic accessibility with CL-20.Hopefully,the proposed strategy could be utilized in further molecular design to gain various scaffolds,especially cage structures,for different demands.

Crystalline-State Solvent:Metal-Organic Frameworks as a Platform for Intercepting Aggregation-Caused Quenching

The sequestration of organic luminescent molecules(OLMs)within cage-based metal-organic frameworks(MOFs)as a dispersion platform has been developed to impede aggregation-caused quenching(ACQ).The homogenous encapsulation of distinct luminescent guests of different sizes and emissive behaviors in the cage structure of a MOF resulted in high fluorescent quantum yields of 44.8%for DAPI@NKU-110(DAPI=4',6-diamidino-2-phenylindole),65.4%for TPPA@NKU-110(TPPA=tris(4-(pyridin-4-yl)phenyl)amine),31.3%for R6G@NKU-110(R6G=Rhodamine 6G),and 58.3%for PY@NKU-110(PY=Pyronin Y),attributable to the confinement effect caused by the rigid cages of NKU-110.More significantly,a positive correlation of the encapsulated quantity of OLMs with their concentration in the in-situ solvothermal reaction was unveiled by spectral analysis and utilized to facilely fabricate a white-light-emitting crystal material TPPA+R6G@NKU-110.This material features a large crystal size on the millimeter-scale,broadband white emission,ideal CIE coordinates(0.33,0.34),and a high quantum yield(49.1%)when excited at 365 nm.Moreover,such a strategy can be easily generalized to an abundance of other cage-based MOFs and a plentiful volume of OLMs for the future development of colorful,high performance luminescent materials.

High Fluorescence Porous Organic Cage for Sensing Divalent Palladium Ion and Encapsulating Fine Palladium Nanoparticles

Porous organic cages(POCs)as an innovative type of porous molecular materials enable multifunctional applications.Herein,a fluorescence POC(denoted as 1)has been constructed by means of 5/5'-((2/5-dimethoxy-l/4-phenylene)bis(ethyne-2/1-diyl))diiso-phthalaldehyde condensing with cyclohexanediamine enantiomer with the aid of trifluoroacetic acid.1 exhibits the permanent void and prominent fluorescence with relative quantum yield of 73%confirmed by gas sorption and emission experiments,respectively.Moreover,this organic cage is capable of sensing diavalent Pd2+according to the fluorescence response to the addition of various metal ions.The dispersion of 1 in methanol containing palladium acetate was stirred at 25℃and then 80℃to reduce Pd2+ions into nanoparticles(NPs),leading to the composite(Pd@l)composed of fine Pd NPs with the size of co.1.8 nm.The catalytic nature of Pd@l over NaBH4 promoted the degeneration of nitrobenzene and congo red.This work introduces one new case of POCs with versatile properties and functions,including ion fluorescence recognition,fine Pd NPs stabilizer,and gas adsorption,enriching the family of POC-based materials.

On Desilylation of 13-Vertex Carborane 1,2-Me_(2)Si(CH_(2))_(2)-1,2-C_(2)B_(11)H_(11)

The reasons for facile double desilylation of 13-vertex carborane 1,2-Me_(2)Si(CH_(2))_(2)-1,2-C_(2)B_(11)H_(11)(2)are discussed in this article.New 13-and 14-vertex ruthenacarboranes bearing the same-CH_(2)SiMe_(2)CH_(2)-linkage have been prepared and structurally characterized for comparison.Structural analyses of 13-and 14-vertex heteroboranes as well as control experiments suggest that the facile double desilylation of 2 on silica gel can be attributed to the joint actions of several factors involving the high ring-strain of exo five-membered C_(4)Si ring,Lewis acidity of Si atom and Brønsted acidity of silica surface.

Cage-Ligand Strategy for the Construction of Zr_(4)(embonate)6-Based MOFs with Third-Order Nonlinear-Optical Properties

Herein,we demonstrate a very useful strategy to construct cage-based metal-organic frameworks(MOFs)with third-order nonlinear-optical properties.More specifically,by employing the Zr_(4)L_(6)(L=embonate)cages to assembly with N-contained ligands and Mn^(2+)/Zn^(2+) ions,four Zr_(4)L_(6)-cage-based MOFs have been synthesized and structurally characterized.Among them,a 3D framework with strong aromatic π−πstacking force exhibits a good optical limiting effect.

Oxidation of N-benzyl groups

The additive reactivity of 2,6,8,12-tetraacetyl-4, 10-dibenzyl-2,4,6,8,10,12-hexazatetracyclo [5.5.0.05.9. 03.11] dodecane (3) in several conditions was studied. It was found that the N-benzyl groups in compound 3 could be oxidized to benzoyl groups by Cr(VI) reagents, and could be removed by cerium ammonium nitrate (CAN), meanwhile nitroamine products were given.

Oxidation of hexabenzylhexaazaisowurtzitane

Oxidation of hexabenzylhexaazaisowurtzitane by different Cr(VI) reagents has been studied, and a very stable amide product, hexabenzoylhexaazaisowurtzitane, has been obtained.