研究目的
To synthesize and study the photochromic and chiroptical properties of new azobenzene-derived glycomacrolactones for reversible photocontrol of glycoconjugates.
研究成果
The synthesized glycomacrolactones exhibit excellent reversible photoisomerization, high thermal stability, and significant conformational and chiroptical changes. They enable convergent synthesis of diastereomers and have potential applications in light-controlled glycobiology.
研究不足
The macrocyclization was challenging and required specific conditions; esterification approaches failed. Z→E photoisomerization was partial due to overlapping absorptions. The study is limited to synthesized compounds and may not generalize to other glycoconjugates.
1：Experimental Design and Method Selection:
The synthesis involved a one-pot O-alkylation mediated macrocyclization approach using di-O-bromoacetyl thioglycosides and 2,2'-dihydroxyazobenzene, with optimization of conditions (e.g., solvent, base, crown ether) for macrocycle formation. Photochromic properties were studied using UV-Vis and NMR spectroscopy, and chiroptical properties via CD and optical rotation measurements. DFT and TD-DFT calculations were used for geometry optimization and spectral simulation.
2：Sample Selection and Data Sources:
Thioglycosides (5-7) were used as starting materials, synthesized from known compounds. Azobenzene derivatives were commercially available or prepared as described.
3：List of Experimental Equipment and Materials:
Instruments included a JEOL ECS-400 NMR spectrometer, Q-TOF mass spectrometer, JASCO P-2000 polarimeter, Cary-5000 spectrophotometer, Hamamatsu LC6 Lightningcure lamp with filters, Ophir photodiode, Jobin Yvon CD 6 spectropolarimeter, and Gaussian09 software for DFT calculations. Materials included solvents (e.g., acetone, DMF), reagents (e.g., bromoacetyl bromide, 2,2'-dihydroxyazobenzene), and bases (e.g., Cs2CO3, K2CO3).
4：3). Experimental Procedures and Operational Workflow:
4. Experimental Procedures and Operational Workflow: Synthesis of O-bromoacetyl thioglycosides (8-10) via reaction with bromoacetyl bromide and pyridine. Macrocyclization with 2,2'-dihydroxyazobenzene under various conditions (e.g., in acetone or DMF with carbonate and crown ether). Purification by column chromatography. Photoisomerization studies with irradiation at 365 nm and 435 nm, monitored by UV-Vis and NMR. Thermal stability measurements at 40°C and 60°C. CD and optical rotation measurements. DFT geometry optimization and TD-DFT calculations for CD spectra.
5：Data Analysis Methods:
NMR data analysis for conformational changes, UV-Vis spectroscopy for photoisomerization kinetics, CD spectroscopy for chiroptical properties, and DFT calculations for theoretical predictions.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容-
NMR Spectrometer
ECS-400
JEOL
Recording 1H and 13C-NMR spectra for structural analysis and monitoring photoisomerization.
-
Polarimeter
P-2000
JASCO
Measuring optical rotation [α]D for chiroptical properties.
-
Spectrophotometer
Cary-5000
Agilent Technologies
Recording absorption spectra for photochromic studies.
-
Lamp
LC6 Lightningcure
Hamamatsu
Providing irradiation at specific wavelengths (365 nm and 435 nm) for photoisomerization.
-
Photodiode
PD300-UV
Ophir
Measuring irradiation power.
-
Mass Spectrometer
Q-TOF
Recording HRMS (ESI) spectra for molecular weight confirmation.
-
Spectropolarimeter
CD 6
Jobin Yvon
Performing circular dichroism spectra for chiroptical analysis.
-
Software
Gaussian09
Gaussian
Performing DFT and TD-DFT calculations for geometry optimization and spectral simulation.
-
登录查看剩余6件设备及参数对照表
查看全部
