Abstract
Molecular packing in light harvesting 2D assemblies of photocatalytic materials is a critical factor for solar-to-fuel conversion efficiency. However, structure-function correlations have yet to be fully established. This is partly due to the difficulties in extracting the molecular arrangements from the complex 3D powder averaged diffraction patterns of 2D lattices, obtained via in situ wide-angle X-ray scattering. Here, we develop a scattering theory formalism and couple it with a simple geometrical model for the molecular shape of chromophore 9-methoxy-N-(sodium hexanoate)perylene-3,4-dicarboximide (MeO-PMI) used in our study. This generally applicable method fully reproduces the measured diffraction pattern including the asymmetric line shapes for the Bragg reflections and yields the molecular packing arrangement within a 2D crystal structure with a remarkable degree of detail. We find an approximate edge-centered herringbone structure for the PMI fused aromatic rings and ordering of the carboxypentyl chains above and below the nanosheets. Such a packing arrangement differs from the more symmetric face-to-face orientation of the unsubstituted PMI rings. This structural difference is correlated to our measurement of the reduced catalytic performance of MeO-PMI nanosheets as compared to the mesoscopically similar unsubstituted PMI assemblies.
| Original language | English |
|---|---|
| Pages (from-to) | 1047-1054 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry C |
| Volume | 121 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jan 19 2017 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Surfaces, Coatings and Films
- Physical and Theoretical Chemistry
Cite this
Molecular Packing of Amphiphilic Nanosheets Resolved by X-ray Scattering. / Harutyunyan, Boris; Dannenhoffer, Adam; Kewalramani, Sumit; Aytun, Taner; Fairfield, Daniel J.; Stupp, Samuel I; Bedzyk, Michael J.
In: Journal of Physical Chemistry C, Vol. 121, No. 2, 19.01.2017, p. 1047-1054.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Molecular Packing of Amphiphilic Nanosheets Resolved by X-ray Scattering
AU - Harutyunyan, Boris
AU - Dannenhoffer, Adam
AU - Kewalramani, Sumit
AU - Aytun, Taner
AU - Fairfield, Daniel J.
AU - Stupp, Samuel I
AU - Bedzyk, Michael J.
PY - 2017/1/19
Y1 - 2017/1/19
N2 - Molecular packing in light harvesting 2D assemblies of photocatalytic materials is a critical factor for solar-to-fuel conversion efficiency. However, structure-function correlations have yet to be fully established. This is partly due to the difficulties in extracting the molecular arrangements from the complex 3D powder averaged diffraction patterns of 2D lattices, obtained via in situ wide-angle X-ray scattering. Here, we develop a scattering theory formalism and couple it with a simple geometrical model for the molecular shape of chromophore 9-methoxy-N-(sodium hexanoate)perylene-3,4-dicarboximide (MeO-PMI) used in our study. This generally applicable method fully reproduces the measured diffraction pattern including the asymmetric line shapes for the Bragg reflections and yields the molecular packing arrangement within a 2D crystal structure with a remarkable degree of detail. We find an approximate edge-centered herringbone structure for the PMI fused aromatic rings and ordering of the carboxypentyl chains above and below the nanosheets. Such a packing arrangement differs from the more symmetric face-to-face orientation of the unsubstituted PMI rings. This structural difference is correlated to our measurement of the reduced catalytic performance of MeO-PMI nanosheets as compared to the mesoscopically similar unsubstituted PMI assemblies.
AB - Molecular packing in light harvesting 2D assemblies of photocatalytic materials is a critical factor for solar-to-fuel conversion efficiency. However, structure-function correlations have yet to be fully established. This is partly due to the difficulties in extracting the molecular arrangements from the complex 3D powder averaged diffraction patterns of 2D lattices, obtained via in situ wide-angle X-ray scattering. Here, we develop a scattering theory formalism and couple it with a simple geometrical model for the molecular shape of chromophore 9-methoxy-N-(sodium hexanoate)perylene-3,4-dicarboximide (MeO-PMI) used in our study. This generally applicable method fully reproduces the measured diffraction pattern including the asymmetric line shapes for the Bragg reflections and yields the molecular packing arrangement within a 2D crystal structure with a remarkable degree of detail. We find an approximate edge-centered herringbone structure for the PMI fused aromatic rings and ordering of the carboxypentyl chains above and below the nanosheets. Such a packing arrangement differs from the more symmetric face-to-face orientation of the unsubstituted PMI rings. This structural difference is correlated to our measurement of the reduced catalytic performance of MeO-PMI nanosheets as compared to the mesoscopically similar unsubstituted PMI assemblies.
UR - http://www.scopus.com/inward/record.url?scp=85020022545&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020022545&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.6b11391
DO - 10.1021/acs.jpcc.6b11391
M3 - Article
AN - SCOPUS:85020022545
VL - 121
SP - 1047
EP - 1054
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 2
ER -