Adv Polym Sci (2013) 261: 271–294
DOI: 10.1007/12_2013_245
© Springer-Verlag Berlin Heidelberg 2013
Published online: 20 October 2013
Mechanically Interlaced and Interlocked
Donor–Acceptor Foldamers
Carson J. Bruns and J. Fraser Stoddart
Abstract The emergence of a class of organic oligomers and polymers that lie at
the intersection of the fields of mechanically interlocked molecules (MIMs) and
synthetic foldamers is described in this review. These macromolecules are based on
4,4
0 -bipyridinium (BIPY
2+ ) and 1,5-dioxynaphthalene (DNP) recognition units
incorporated into linear oligo- or polymeric chains (threads) and macrocycles
(rings), where the threads fold their way through a series of rings in a serpentinelike fashion. The well-defined geometries of these polyelectrolytes are rendered by
the [C–H Á Á Á O] hydrogen bonding interactions that transpire between the
polyether chains appended to DNP and the acidic protons of BIPY
2+ , as well as
the π–π and donor–acceptor (D–A) charge transfer interactions that cause DNP and
BIPY
2+ units to pack into extended mixed stacks. The unique folding motif of these
pseudorotaxanes and rotaxanes makes them attractive candidates for novel
multiferroic and mechanically tunable materials.
Keywords [C–H Á Á Á O]·interactions Á Donor–acceptor Á Foldamers Á Mechanostereochemistry Á Polyelectrolytes Á Rotaxanes Á π–π interactions
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
2 D–A Pseudorotaxane Foldamers in the Solid State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
2.1 Early Signs of Extended D–A Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
2.2 Infinite-Chain Lattice of D–A Oligo-Pseudorotaxanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
C.J. Bruns and J.F. Stoddart (*)
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston,
IL 60208, USA
e-mail: stoddart@northwestern.edu
DOI: 10.1007/12_2013_245
© Springer-Verlag Berlin Heidelberg 2013
Published online: 20 October 2013
Mechanically Interlaced and Interlocked
Donor–Acceptor Foldamers
Carson J. Bruns and J. Fraser Stoddart
Abstract The emergence of a class of organic oligomers and polymers that lie at
the intersection of the fields of mechanically interlocked molecules (MIMs) and
synthetic foldamers is described in this review. These macromolecules are based on
4,4
0 -bipyridinium (BIPY
2+ ) and 1,5-dioxynaphthalene (DNP) recognition units
incorporated into linear oligo- or polymeric chains (threads) and macrocycles
(rings), where the threads fold their way through a series of rings in a serpentinelike fashion. The well-defined geometries of these polyelectrolytes are rendered by
the [C–H Á Á Á O] hydrogen bonding interactions that transpire between the
polyether chains appended to DNP and the acidic protons of BIPY
2+ , as well as
the π–π and donor–acceptor (D–A) charge transfer interactions that cause DNP and
BIPY
2+ units to pack into extended mixed stacks. The unique folding motif of these
pseudorotaxanes and rotaxanes makes them attractive candidates for novel
multiferroic and mechanically tunable materials.
Keywords [C–H Á Á Á O]·interactions Á Donor–acceptor Á Foldamers Á Mechanostereochemistry Á Polyelectrolytes Á Rotaxanes Á π–π interactions
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
2 D–A Pseudorotaxane Foldamers in the Solid State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
2.1 Early Signs of Extended D–A Stacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
2.2 Infinite-Chain Lattice of D–A Oligo-Pseudorotaxanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
C.J. Bruns and J.F. Stoddart (*)
Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston,
IL 60208, USA
e-mail: stoddart@northwestern.edu