TY - JOUR
T1 - Light-harvesting and ultrafast energy migration in porphyrin-based metal-organic frameworks
AU - Son, Ho Jin
AU - Jin, Shengye
AU - Patwardhan, Sameer
AU - Wezenberg, Sander J.
AU - Jeong, Nak Cheon
AU - So, Monica
AU - Wilmer, Christopher E.
AU - Sarjeant, Amy A.
AU - Schatz, George C.
AU - Snurr, Randall Q.
AU - Farha, Omar K.
AU - Wiederrecht, Gary P.
AU - Hupp, Joseph T.
PY - 2013/1/16
Y1 - 2013/1/16
N2 - Given that energy (exciton) migration in natural photosynthesis primarily occurs in highly ordered porphyrin-like pigments (chlorophylls), equally highly ordered porphyrin-based metal-organic frameworks (MOFs) might be expected to exhibit similar behavior, thereby facilitating antenna-like light-harvesting and positioning such materials for use in solar energy conversion schemes. Herein, we report the first example of directional, long-distance energy migration within a MOF. Two MOFs, namely F-MOF and DA-MOF that are composed of two Zn(II) porphyrin struts [5,15-dipyridyl-10,20-bis(pentafluorophenyl)porphinato]zinc(II) and [5,15-bis[4-(pyridyl)ethynyl]-10,20-diphenylporphinato]zinc(II), respectively, were investigated. From fluorescence quenching experiments and theoretical calculations, we find that the photogenerated exciton migrates over a net distance of up to ∼45 porphyrin struts within its lifetime in DA-MOF (but only ∼3 in F-MOF), with a high anisotropy along a specific direction. The remarkably efficient exciton migration in DA-MOF is attributed to enhanced π-conjugation through the addition of two acetylene moieties in the porphyrin molecule, which leads to greater Q-band absorption intensity and much faster exciton-hopping (energy transfer between adjacent porphyrin struts). The long distance and directional energy migration in DA-MOF suggests promising applications of this compound or related compounds in solar energy conversion schemes as an efficient light-harvesting and energy-transport component.
AB - Given that energy (exciton) migration in natural photosynthesis primarily occurs in highly ordered porphyrin-like pigments (chlorophylls), equally highly ordered porphyrin-based metal-organic frameworks (MOFs) might be expected to exhibit similar behavior, thereby facilitating antenna-like light-harvesting and positioning such materials for use in solar energy conversion schemes. Herein, we report the first example of directional, long-distance energy migration within a MOF. Two MOFs, namely F-MOF and DA-MOF that are composed of two Zn(II) porphyrin struts [5,15-dipyridyl-10,20-bis(pentafluorophenyl)porphinato]zinc(II) and [5,15-bis[4-(pyridyl)ethynyl]-10,20-diphenylporphinato]zinc(II), respectively, were investigated. From fluorescence quenching experiments and theoretical calculations, we find that the photogenerated exciton migrates over a net distance of up to ∼45 porphyrin struts within its lifetime in DA-MOF (but only ∼3 in F-MOF), with a high anisotropy along a specific direction. The remarkably efficient exciton migration in DA-MOF is attributed to enhanced π-conjugation through the addition of two acetylene moieties in the porphyrin molecule, which leads to greater Q-band absorption intensity and much faster exciton-hopping (energy transfer between adjacent porphyrin struts). The long distance and directional energy migration in DA-MOF suggests promising applications of this compound or related compounds in solar energy conversion schemes as an efficient light-harvesting and energy-transport component.
UR - http://www.scopus.com/inward/record.url?scp=84872537814&partnerID=8YFLogxK
U2 - 10.1021/ja310596a
DO - 10.1021/ja310596a
M3 - Article
C2 - 23249338
AN - SCOPUS:84872537814
SN - 0002-7863
VL - 135
SP - 862
EP - 869
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 2
ER -