A radically configurable six-state compound.
Most organic radicals possess short lifetimes and quickly undergo dimerization or oxidation. Here, we report on the synthesis by radical templation of a class of air- and water-stable organic radicals, trapped within a homo[2]catenane composed of two rigid and fixed cyclobis(paraquat-p-phenylene) rings. The highly energetic octacationic homo[2]catenane, which is capable of accepting up to eight electrons, can be configured reversibly, both chemically and electrochemically, between each one of six experimentally accessible redox states (0, 2+, 4+, 6+, 7+, and 8+) from within the total of nine states evaluated by quantum mechanical methods. All six of the observable redox states have been identified by electrochemical techniques, three (4+, 6+, and 7+) have been characterized by x-ray crystallography, four (4+, 6+, 7+, and 8+) by electron paramagnetic resonance spectroscopy, one (7+) by superconducting quantum interference device magnetometry, and one (8+) by nuclear magnetic resonance spectroscopy.
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
Jonathan C
JC
Barnes
Albert C
AC
Fahrenbach
Dennis
D
Cao
Scott M
SM
Dyar
Marco
M
Frasconi
Marc A
MA
Giesener
Diego
D
Benítez
Ekaterina
E
Tkatchouk
Oleksandr
O
Chernyashevskyy
Weon Ho
WH
Shin
Hao
H
Li
Srinivasan
S
Sampath
Charlotte L
CL
Stern
Amy A
AA
Sarjeant
Karel J
KJ
Hartlieb
Zhichang
Z
Liu
Raanan
R
Carmieli
Youssry Y
YY
Botros
Jang Wook
JW
Choi
Alexandra M Z
AM
Slawin
John B
JB
Ketterson
Michael R
MR
Wasielewski
William A
WA
Goddard
J Fraser
JF
Stoddart