TY - JOUR
T1 - Synthesis and electrochemical properties of cavitands functionalized with 4,4′-bipyridinium units
AU - Román, Esteban
AU - Chas, Marcos
AU - María Quintela, José
AU - Peinador, Carlos
AU - Kaifer, Angel E.
N1 - Funding Information:
The authors are grateful to the US National Science Foundation (to AEK, CHE-9982014), Xunta de Galicia (to JMQ and CP, PGIDT00PXI 10306PR) and the Ministerio de Educación y Cultura (to JMQ and CP, BQU2000-0237) for the support of this research work. E. R. acknowledges a Maytag graduate fellowship from the University of Miami. M. C. thanks the Fundación Areces for a predoctoral fellowship.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/1/21
Y1 - 2002/1/21
N2 - Four new brominated resorcinarene cavitand derivatives (3-6) and the already known tetrakis(bromomethyl)cavitand 2 have been synthesized, starting from the tetramethylcavitand 1. These brominated cavitands constitute excellent building blocks for the covalent assembly of new structures containing one (8), two (9 and 10), three (11) and four (7) monoquaternized bipyridine units attached to the upper rim of the cavitand bowl. The free terminal nitrogens in these structures can be methylated to yield compounds with one to four 4,4′-bipyridinium (viologen) units attached to the cavitand (12-16), or treated with monobromocavitand 3 to produce oligomeric structures containing from two to five cavitand units connected by viologen residues (17-21). Compounds 8-16, 18 and 20 show the electrochemical reactivity anticipated from their reducible units (mono- or diquaternized bipyridines) with no detectable level of electronic communication between them. Surprisingly, compounds 17, 19 and 21 exhibit more complicated electrochemical behavior, which simplifies and becomes more reversible as the temperature increases.
AB - Four new brominated resorcinarene cavitand derivatives (3-6) and the already known tetrakis(bromomethyl)cavitand 2 have been synthesized, starting from the tetramethylcavitand 1. These brominated cavitands constitute excellent building blocks for the covalent assembly of new structures containing one (8), two (9 and 10), three (11) and four (7) monoquaternized bipyridine units attached to the upper rim of the cavitand bowl. The free terminal nitrogens in these structures can be methylated to yield compounds with one to four 4,4′-bipyridinium (viologen) units attached to the cavitand (12-16), or treated with monobromocavitand 3 to produce oligomeric structures containing from two to five cavitand units connected by viologen residues (17-21). Compounds 8-16, 18 and 20 show the electrochemical reactivity anticipated from their reducible units (mono- or diquaternized bipyridines) with no detectable level of electronic communication between them. Surprisingly, compounds 17, 19 and 21 exhibit more complicated electrochemical behavior, which simplifies and becomes more reversible as the temperature increases.
KW - 4,4′-bipyridinium units
KW - Cavitands
KW - Electrochemical properties
KW - Synthesis
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U2 - 10.1016/S0040-4020(01)01109-7
DO - 10.1016/S0040-4020(01)01109-7
M3 - Article
AN - SCOPUS:0037147927
VL - 58
SP - 699
EP - 709
JO - Tetrahedron
JF - Tetrahedron
SN - 0040-4020
IS - 4
ER -