Abstract
Rotacatenanes are exotic molecular compounds that can be visualized as a unique combination of a [2]catenane and a [2]rotaxane, thereby combining both the circumrotation of the ring component (rotary motion) and the shuttling of the dumbbell component (translational motion) in one structure. Herein, we describe a strategy for the synthesis of a new switchable [3]rotacatenane and the investigation of its switching properties, which rely on the formation of tetrathiafulvalene (TTF) radical π-dimer interactions-namely, the mixed-valence state (TTF2)+. and the radical-cation dimer state (TTF+.)2-under ambient conditions. A template-directed approach, based on donor-acceptor interactions, has been developed, resulting in an improved yield of the key precursor [2]catenane, prior to rotacatenation. The nature of the binding between the [2]catenane and selected π-electron-rich templates has been elucidated by using X-ray crystallography and UV/Vis spectroscopy as well as isothermal titration microcalorimetry. The multistate switching mechanism of the [3]rotacatenane has been demonstrated by cyclic voltammetry and EPR spectroscopy. Most notably, the radical-cation dimer state (TTF+.)2 has been shown to enter into an equilibrium by forming the co-conformation in which the two 1,5-dioxynaphthalene (DNP) units co-occupy the cavity of tetracationic cyclophane, thus enforcing the separation of TTF radical-cation dimer (TTF +.)2. The population ratio of this equilibrium state was found to be 1:1. We believe that this research demonstrates the power of constructing complex molecular machines using template-directed protocols, enabling us to make the transition from simple molecular switches to their multistate variants for enhancing information storage in molecular electronic devices.
| Original language | English |
|---|---|
| Pages (from-to) | 213-222 |
| Number of pages | 10 |
| Journal | Chemistry - A European Journal |
| Volume | 17 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 3 2011 |
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Keywords
- molecular switches
- radical dimerization
- rotacatenanes
- template-directed synthesis
- tetrathiafulvalenes
ASJC Scopus subject areas
- Chemistry(all)
Cite this
A multistate switchable [3]rotacatenane. / Barin, Gokhan; Coskun, Ali; Friedman, Douglas C.; Olson, Mark A.; Colvin, Michael T.; Carmielli, Raanan; Dey, Sanjeev K.; Bozdemir, O. Altan; Wasielewski, Michael R; Stoddart, J. Fraser.
In: Chemistry - A European Journal, Vol. 17, No. 1, 03.01.2011, p. 213-222.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A multistate switchable [3]rotacatenane
AU - Barin, Gokhan
AU - Coskun, Ali
AU - Friedman, Douglas C.
AU - Olson, Mark A.
AU - Colvin, Michael T.
AU - Carmielli, Raanan
AU - Dey, Sanjeev K.
AU - Bozdemir, O. Altan
AU - Wasielewski, Michael R
AU - Stoddart, J. Fraser
PY - 2011/1/3
Y1 - 2011/1/3
N2 - Rotacatenanes are exotic molecular compounds that can be visualized as a unique combination of a [2]catenane and a [2]rotaxane, thereby combining both the circumrotation of the ring component (rotary motion) and the shuttling of the dumbbell component (translational motion) in one structure. Herein, we describe a strategy for the synthesis of a new switchable [3]rotacatenane and the investigation of its switching properties, which rely on the formation of tetrathiafulvalene (TTF) radical π-dimer interactions-namely, the mixed-valence state (TTF2)+. and the radical-cation dimer state (TTF+.)2-under ambient conditions. A template-directed approach, based on donor-acceptor interactions, has been developed, resulting in an improved yield of the key precursor [2]catenane, prior to rotacatenation. The nature of the binding between the [2]catenane and selected π-electron-rich templates has been elucidated by using X-ray crystallography and UV/Vis spectroscopy as well as isothermal titration microcalorimetry. The multistate switching mechanism of the [3]rotacatenane has been demonstrated by cyclic voltammetry and EPR spectroscopy. Most notably, the radical-cation dimer state (TTF+.)2 has been shown to enter into an equilibrium by forming the co-conformation in which the two 1,5-dioxynaphthalene (DNP) units co-occupy the cavity of tetracationic cyclophane, thus enforcing the separation of TTF radical-cation dimer (TTF +.)2. The population ratio of this equilibrium state was found to be 1:1. We believe that this research demonstrates the power of constructing complex molecular machines using template-directed protocols, enabling us to make the transition from simple molecular switches to their multistate variants for enhancing information storage in molecular electronic devices.
AB - Rotacatenanes are exotic molecular compounds that can be visualized as a unique combination of a [2]catenane and a [2]rotaxane, thereby combining both the circumrotation of the ring component (rotary motion) and the shuttling of the dumbbell component (translational motion) in one structure. Herein, we describe a strategy for the synthesis of a new switchable [3]rotacatenane and the investigation of its switching properties, which rely on the formation of tetrathiafulvalene (TTF) radical π-dimer interactions-namely, the mixed-valence state (TTF2)+. and the radical-cation dimer state (TTF+.)2-under ambient conditions. A template-directed approach, based on donor-acceptor interactions, has been developed, resulting in an improved yield of the key precursor [2]catenane, prior to rotacatenation. The nature of the binding between the [2]catenane and selected π-electron-rich templates has been elucidated by using X-ray crystallography and UV/Vis spectroscopy as well as isothermal titration microcalorimetry. The multistate switching mechanism of the [3]rotacatenane has been demonstrated by cyclic voltammetry and EPR spectroscopy. Most notably, the radical-cation dimer state (TTF+.)2 has been shown to enter into an equilibrium by forming the co-conformation in which the two 1,5-dioxynaphthalene (DNP) units co-occupy the cavity of tetracationic cyclophane, thus enforcing the separation of TTF radical-cation dimer (TTF +.)2. The population ratio of this equilibrium state was found to be 1:1. We believe that this research demonstrates the power of constructing complex molecular machines using template-directed protocols, enabling us to make the transition from simple molecular switches to their multistate variants for enhancing information storage in molecular electronic devices.
KW - molecular switches
KW - radical dimerization
KW - rotacatenanes
KW - template-directed synthesis
KW - tetrathiafulvalenes
UR - http://www.scopus.com/inward/record.url?scp=78651085711&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78651085711&partnerID=8YFLogxK
U2 - 10.1002/chem.201002152
DO - 10.1002/chem.201002152
M3 - Article
VL - 17
SP - 213
EP - 222
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
SN - 0947-6539
IS - 1
ER -