TY - JOUR
T1 - Halogen bonding versus hydrogen bonding in driving self-assembly and performance of light-responsive supramolecular polymers
AU - Priimagi, Arri
AU - Cavallo, Gabriella
AU - Forni, Alessandra
AU - Gorynsztejn-Leben, Mikael
AU - Kaivola, Matti
AU - Metrangolo, Pierangelo
AU - Milani, Roberto
AU - Shishido, Atsushi
AU - Pilati, Tullio
AU - Resnati, Giuseppe
AU - Terraneo, Giancarlo
PY - 2012
Y1 - 2012
N2 - Halogen bonding is arguably the least exploited among the many non‐covalent interactions used in dictating molecular self‐assembly. However, its directionality renders it unique compared to ubiquitous hydrogen bonding. Here, the role of this directionality in controlling the performance of light‐responsive supramolecular polymers is highlighted. In particular, it is shown that light‐induced surface patterning, a unique phenomenon occurring in azobenzene‐containing polymers, is more efficient in halogen‐bonded polymer–azobenzene complexes than in the analogous hydrogen‐bonded complexes. A systematic study is performed on a series of azo dyes containing different halogen or hydrogen bonding donor moieties, complexed to poly(4‐vinylpyridine) backbone. Through single‐atom substitution of the bond‐donor, control of both the strength and the nature of the noncovalent interaction between the azobenzene units and the polymer backbone is achieved. Importantly, such substitution does not significantly alter the electronic properties of the azobenzene units, hence providing us with unique tools in studying the structure–performance relationships in the light‐induced surface deformation process. The results represent the first demonstration of light‐responsive halogen‐bonded polymer systems and also highlight the remarkable potential of halogen bonding in fundamental studies of photoresponsive azobenzene‐containing polymers.
AB - Halogen bonding is arguably the least exploited among the many non‐covalent interactions used in dictating molecular self‐assembly. However, its directionality renders it unique compared to ubiquitous hydrogen bonding. Here, the role of this directionality in controlling the performance of light‐responsive supramolecular polymers is highlighted. In particular, it is shown that light‐induced surface patterning, a unique phenomenon occurring in azobenzene‐containing polymers, is more efficient in halogen‐bonded polymer–azobenzene complexes than in the analogous hydrogen‐bonded complexes. A systematic study is performed on a series of azo dyes containing different halogen or hydrogen bonding donor moieties, complexed to poly(4‐vinylpyridine) backbone. Through single‐atom substitution of the bond‐donor, control of both the strength and the nature of the noncovalent interaction between the azobenzene units and the polymer backbone is achieved. Importantly, such substitution does not significantly alter the electronic properties of the azobenzene units, hence providing us with unique tools in studying the structure–performance relationships in the light‐induced surface deformation process. The results represent the first demonstration of light‐responsive halogen‐bonded polymer systems and also highlight the remarkable potential of halogen bonding in fundamental studies of photoresponsive azobenzene‐containing polymers.
KW - Halogen bonding
KW - self-assembly
KW - surface relief gratings
KW - optically active materials
KW - supramolecular polymers
U2 - 10.1002/adfm.201200135
DO - 10.1002/adfm.201200135
M3 - Article
SN - 1616-301X
VL - 22
SP - 2572
EP - 2579
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 12
ER -