CHARGE-TRANSFER INTERACTIONS OF AMINES WITH TETRAHALOMETHANES - X-RAY CRYSTAL-STRUCTURES OF THE DONOR-ACCEPTOR COMPLEXES OF QUINUCLIDINE AND DIAZABICYCLO[2.2.2]OCTANE WITH CARBON TETRABROMIDE
CHARGE-TRANSFER INTERACTIONS OF AMINES WITH TETRAHALOMETHANES - X-RAY CRYSTAL-STRUCTURES OF THE DONOR-ACCEPTOR COMPLEXES OF QUINUCLIDINE AND DIAZABICYCLO[2.2.2]OCTANE WITH CARBON TETRABROMIDE
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DOI：
10.1021/jo00384a013
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发表时间：
1987-04-17
影响因子：
3.6
通讯作者：
KOCHI, JK
中科院分区：
文献类型：
--
作者：
BLACKSTOCK, SC;LORAND, JP;KOCHI, JK
通过观察电荷转移（CT）吸收带，用光谱法检查了各种胺与四氯化碳、四溴化物和四碘化物的分子缔合。在胺中，奎宁环和二氮杂双环[2.2. 2]正辛烷（Dabco）为形成电子给体受体或EDA络合物提供了最明确的证据。通过Benesi-Hildebrand方法对形成常数K= 3.2M-12的定量评估表明Dabco和CBr 4的适度弱的1：1 EDA络合物。然而，络合物在氯仿中的不溶性允许生长适合于X射线晶体学的单晶。晶体Dabco复合物的分子结构由二胺和CBr 4的交替平面组成，其中每个受体与两个供体单元结合以形成一系列并列的无限链。相比之下，奎宁复合物由离散的供体-受体相互作用对组成，其中每个CBr 4仅与单个供体结合，晶胞由四个这样的对组成，每个对位于不同的三重轴上。Dabco-CBr 4复合物的链状结构和奎宁环-CBr 4复合物的成对结构之间的差异表现在它们的固态CT光谱中。通过紫外-可见光谱、红外光谱和~（13）C NMR等多种光谱技术，比较了Dabco的EDA晶体与溶液中1：1配合物的CT相互作用。本文还对Dabco-CBr_4配合物的电荷转移光化学进行了简要的研究。
The molecular association of various amines with carbon tetrachloride, tetrabromide, and tetraiodide is examined spectroscopically by observing the charge-transfer (CT) absorption bands. Among the amines, quinuclidine and diazabicyclo [2.2. 2] octane (Dabco) afford the most cleancut evidence for the formation of electron-donor-acceptor or EDA complexes. Quantitative evaluation of the formation constant K= 3.2 M" 1 2by the Benesi-Hildebrand method indicates a moderately weak 1: 1 EDA complex of Dabco and CBr4. However, the insolubility of the complexes in chloroform allowssingle crystals suitable for X-ray crystallography to be grown. The molecular structure of the crystalline Dabco complex consists of alternating planes of the diamine and CBr4 in which each acceptor is bound to two donor units to form a series of juxtaposed, infinite chains. In contrast, the quinuclidine complex consists of discrete pairs of donor-acceptor interactions in which every CBr4 is bound to only a single donor, the unit cell consisting of four such pairs each residing on a different three-fold axis. The difference between the catenated structure of the Dabco-CBr4 complex and the pairwise structure of the quinuclidine-CBr4 complex is manifested in their solid-state CT spectra. The CT interaction in the EDA crystal of Dabco is compared with that of the 1: 1 complex in solution by a variety of spectral techniques including UV-vis, infrared, and and 13C NMR. The charge-transfer photochemistry of the Dabco-CBr4complex is also examined briefly.