TY  - JOUR
A1  - Bock, Hans
A1  - Arad, Claudia
A1  - Näther, Christian
A1  - Göbel, Ilka
A1  - John, Andreas
A1  - Baur, Rüdiger
T1  - Elektronentransfer und Kontaktionen-Bildung, 45 [1, 2] Strukturänderungen bei der Einelektronen-Reduktion von Tetraphenylbutatrien zum Radikalanion und bei der Zweifach-Deprotonierung von Tetraphenyl-butin-2 zum Tetraphenylbutatrien-Dianion
T1  - Electron Transfer and Contact Ion Pair Formation, 45 [1,2] Structural Changes on Single Electron Reduction of Tetraphenylbutatriene to its Radical Anion and on Twofold Deprotonation of Tetraphenylbutyne-2 to the Tetraphenylbutatriene Dianion
T2  - Zeitschrift für Naturforschung, B
N2  - Tetraphenylbutatriene is reduced under aprotic conditions to its ESR/ENDOR-spectroscopically characterized radical anion and to its dianion, with both electron transfers quasireversible according to cyclovoltammetric measurements. The alkali cation salts, the red contact ion pair [(H5C6)4C4·⊖][Na⊕ (H3COCH2CH2OCH3)3] and the dark violet contact ion triple [(H5C6)4C4⊖⊖][Li⊕(H3COCH2CH2OCH3)3]2 can be prepared by single electron reduction at a sodium metal mirror or by twofold de-protonation of 1,1,4,4-tetraphenylbutyne-2 using lithium-n-butyl. Their single crystal structures as well as that of the parent acetylene have been determined at low temperatures. The essential structural changes observed are the twisting of both molecular halves (H5C6)2CC relative to each other with increasing negative charge. The simultaneously resulting bond alternancy >C = C = C = C< → >C⊖ - C ≡ C⊖ - C < within the cumulene chain is discussed based on MNDO calculations for the structures determined.
KW  - Tetraphenylbutatriene Radical Anion and Dianion Salts
KW  - Cyclovoltammetry
KW  - ESR/ENDOR Spectra
KW  - Single Crystal Structures
Y1  - 2014
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/69864
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-698648
SN  - 1865-7117
SN  - 0932-0776
VL  - 51
IS  - 10
SP  - 1381
EP  - 1390
PB  - Verlag der Zeitschrift für Naturforschung
CY  - Tübingen
ER  -