摘要
本文通过光谱法研究了作为新的光敏剂——亚甲蓝(Methylne Blue,MB)在水溶液中的溶液状态,以及其在不同温度时双分子聚集体的解离平衡.通过差示光谱监测了亚甲蓝在水溶液中,其双分子二聚体在温度30～60℃范围内的构成方式的变化:其单分子倾角(a)为48.3～46.1°,双分子面问距离(γ)为 0.576～0.580nm.监测了亚甲蓝在水溶液中其单体最大吸收波长处吸收值随温度的变化,算得其二聚体的解聚常数为(K)3.42×10^-5～4.47×10^-5mol/L,并进一步求出其离解热为5.4×10~5J/mol.
Dissociation equilibrium of bimolecular associates (dimers) of methylene blue (MB) was studied thermodynamically. At 30-60℃, absorption spectra of aqueous solutions of MB showed only monomer and dimer bands. Spectral change with varying temperature suggested that a simple equilibrium between photosensitizer dimers and monomers existed in these solutions. From the temperature-dependence of monomer absorbance, values of dissociation constants K and dissociation enthalpy ΔH were estimated to be 3. 42×10-5(30℃)-4. 47×10-5(60℃) mol/L and 5. 4×105J/mol, respectively.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1995年第12期1381-1385,共5页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金资助课题
关键词
亚甲蓝
解离平衡
吸收光谱
二聚体
Methylene blue, dissociation equilibrium, photosensitizer
