CHARGE-TRANSFER STRUCTURES OF AROMATIC EDA COMPLEXES WITH NORMAL-HETEROATOM-SUBSTITUTED PYRIDINIUM CATIONS
CHARGE-TRANSFER STRUCTURES OF AROMATIC EDA COMPLEXES WITH NORMAL-HETEROATOM-SUBSTITUTED PYRIDINIUM CATIONS
复制标题
DOI：
10.1039/p29920001011
复制
发表时间：
1992-07-01
期刊：
影响因子：
--
通讯作者：
KOCHI, JK
中科院分区：
文献类型：
--
作者：
LEE, KY;KOCHI, JK
具有N-杂原子取代基如X =卤素、硝基、烷氧基和酰氧基的X-吡啶鎓阳离子（即，X-NC_5 H_5 ~+）与N-烷基吡啶阳离子一样，与苯、萘和蒽等不同的给体（ArH）自发地相互作用，生成一系列1：1的电荷转移配合物，在可见光区显示出特征吸收光谱。X-Py ~+电子受体性质的定量评价（通过电化学还原电位E（p）c）表明，N-硝基吡啶（Ec = +0.10 V），N-氟吡啶鎓（E（p）c = -0.66 V），N-乙酰氧基吡啶鎓（E（p）c = -0.81 V），和N-甲氧基吡啶鎓（E（p）c =-1.02V）阳离子在它们与芳族供体的电荷转移相互作用中是强亲电体以产生共面受体-供体对[X-Py+，ArH]，其在结构上与更常见的N-甲基吡啶鎓（E（p）c = -1.32 V）类似物相关。
X-Pyridinium cations with N-heteroatomic substituents such as X = halogen, nitro, alkoxy and acyloxy (i.e., X-NC5H5+), in common with the ubiquitous N-alkylpyridinium cations, interact spontaneously with different benzene, naphthalene and anthracene donors (ArH) to afford a series of 1 :1 charge-transfer complexes showing characteristic absorption spectra in the visible region. Quantitative evaluation of the electron-acceptor properties of X-Py+ (via an electrochemical reduction potential E(p)c) indicates that the N-nitropyridinium (Ec = +0.10 V), N-fluoropyridinium (E(p)c = -0.66 V), N-acetoxypyridinium (E(p)c = -0.81 V), and N-methoxypyridinium (E(p)c = -1.02 V) cations are strong electrophiles in their charge-transfer interaction with aromatic donors to produce cofacial acceptor-donor pairs [X-Py+, ArH] that are structurally related to the more common N-methylpyridinium (E(p)c = -1.32 V) analogues.