[{Na+(thf)2}4(rubrene4−)]: Crystallization and Structure Determination of a Contact-Ion Quintuple for the First π-Hydrocarbon Tetraanion†‡
[{Na+(thf)2}4(rubrene4−)]: Crystallization and Structure Determination of a Contact-Ion Quintuple for the First π-Hydrocarbon Tetraanion†‡
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[{Na+(thf)2}4(红荧烯4−)]：第一个π-烃四阴离子的接触离子五元组的结晶和结构测定†‡
DOI：
10.1002/anie.199606311
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发表时间：
1996
影响因子：
--
通讯作者：
Z. Havlas
中科院分区：
文献类型：
--
作者：
H. Bock;K. Gharagozloo‐Hubmann;C. Näther;N. Nagel;Z. Havlas
电子插入x-烃类C，H，释放的能量小于电子排出所需的能量，在分子态的总能量范围内，与分子阳离子[C，H，]"+相比，所产生的分子阴离子[C，H，]"-位于不带电分子的基态之下。单电子还原生成自由基阴离子盐，其可以是溶剂分离的[Met：，，][C，H，N '-或溶剂共享的接触离子对[Met+（C，H，N'-]，相反，两个电子还原成溶剂分离的或溶剂共享的接触离子三元组[Met-1，]、[C，H，] 2-或[Met：（C，H，2-）] 2-通常引起严重的结构畸变。“例如，在乙烯衍生物R，C= CR，在中性分子还原成二价阴离子时，双键被拉伸成一个单键，两个分子半部围绕该单键扭转;在它们的中心C中心处折叠并质子化;和六元苯环可以变形成”船”构象。虽然在循环伏安法研究中观察到多达四个连续的可逆单电子氧化，但苯的单电子还原只能在极非质子条件下在电位范围限制下实现。延长-
The insertion of electrons into x-hydrocarbons C, H, releases less energy than is needed for electron expulsion, and within the total energy scale for the molecular states, the resulting molecu-lar anions [C, H,]"-are located below the ground state of the uncharged molecule,[''in contrast to the molecular cations [C, H,]"+. Single-electron reductions generate radical anion salts, which can be either solvent-separated [Met:,,][C, H,]'-or solvent-shared contact ion pairs [Met+(C, H,)'-],,,,, and the structural changes upon transition from the neutral molecule to the radical anion are only small.['3 21 In contrast, two electron reductions to either solvent-separated or solvent-shared contact ion triples [Met~ i,],[C, H,] 2-or [Met:(C, HJ2-IFoIv usually cause severe structural distortions."'For instance, in ethylene derivatives R, C= CR,, on reduction of the neutral molecule to the dianion the double bond is stretched to a single one, around which the two molecular halves twist;['] allenes R, C= C= CR, are folded at their central C center and protonated;"] and sixmembered benzene rings can be deformed into a" boat" conformati~ n.'~'Although up to four consecutive reversible one-electron oxidations are observed in cyclic voltammetric studies,"] a single-electron reduction of benzene can be achieved only under extremely aprotic conditions at the potential range limit. Exten-