Electrochemically controlled hydrogen bonding. Nitrobenzenes as simple redox-dependent receptors for arylureas.
Reduction of nitrobenzene derivatives in the presence of arylureas in aprotic solvents results in large positive shifts in potential of the nitrobenzene(0/)(-) cyclic voltammetry wave with little change in wave shape. This behavior is indicative of reversible hydrogen bonding between nitrobenzene radical anions and arylureas. Computer fitting of the cyclic voltammetry of 4-nitroaniline, NA, plus 1,3-diphenylurea in DMF shows essentially no binding between urea and NA in the oxidized state (K(ox) < 1 M(-)(1)), but very strong binding in the reduced state (K(red) = 8 x 10(4) M(-)(1)), along with very rapid rates of hydrogen bond formation (k(f)'s approximately 10(8)-10(10) M(-)(1) s(-)(1)), making this system a fast on/off redox switch.
Bu
Jingjing
J
Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, USA.
Lilienthal
Ninette D
ND
Woods
Jessica E
JE
Nohrden
Cora E
CE
Hoang
Kimphuong T
KT
Truong
Daniel
D
Smith
Diane K
DK