摘要
本文用吸收光谱研究了3,3′-二(γ-磺酸丙基)-9-乙基-4,5,4′,5′-二苯并噻碳菁三乙胺盐(Ⅰ)在DMF-水混合溶剂中存在的状态,求得室温下该染料只存在二聚平衡的浓度范围。用本实验室研制的半导体精密量热系统,测量了25℃染料溶液的稀释热。在含45％ DMF的水中,生成1摩尔二聚体的△H_(298)、△G_(298)及△S_(298)分别为—(49.6±1.3)×10~3J、—(13.1±0.1)×10~3J和—(122.7±3.2)J·K~(-1);在含35％ DMF的水中分别为—(36.0±1.0)×10~3J、—(19.1±0.1)×10~3J和—(54.0±1.5)J·K~(-1)。
The absorption spectra of 3, 3'-di-(γ-sulfopropyl) -9-ethyl-4,5,4',5'-dibenzothia-carbocyani ne triethylamine salt (I) in DMF-H2O mixed solvvents of various compositions showed dimer-mo-nomer equilibrium at room temperature within a certain concentration range. For these solutions, the dilution heat effects were measured with the home-made Versatile Precision Semiconductor Calorimetric System made in this laboratory. Dimerization enthalpy AH, AG and △S, which for 1 mole dimer formation at25℃ in solvents of 45% and 35% DMF (by volume), were found to be: -(49.6±1.3), -(36.0±1.0)kJ;- (13.1±0.1),-(19.9±0.1) kJ and-(122.7±3.2),-(54.0±1.5)J ?K-1 respectively.
出处
《感光科学与光化学》
CSCD
1989年第4期25-30,共6页
Photographic Science and Photochemistry
关键词
菁染料
自缔合
热力学
聚集体
cyanine, photographic spectral sensitizing dye, enthalpy of dimerization, self association
