TY - JOUR
T1 - Twisted, two-faced porphyrins as hosts for bispyridyl fullerenes
T2 - Construction and photophysical properties
AU - Xie, Yongshu
AU - Hill, Jonathan P.
AU - Schumacher, Amy Lea
AU - Sandanayaka, Atula S.D.
AU - Araki, Yasuyuki
AU - Karr, Paul A.
AU - Labuta, Jan
AU - D'Souza, Francis
AU - Ito, Osamu
AU - Anson, Christopher E.
AU - Powell, Annie K.
AU - Ariga, Katsuhiko
PY - 2008/7/17
Y1 - 2008/7/17
N2 - A new class of multichromophoric host compounds capable of binding guest species through two-point coordinative interaction is reported. The hosts contain appended zinc porphyrin (ZnP) moieties connected covalently by acetylene linkages to a central oxoporphyrinogen (OxP) unit through its central macrocyclic nitrogen atoms. Orientation of the ZnP groups was controlled to some extent by variation of the substitution pattern at the OxP N-substituent. Up to four porphyrin appendages are accommodated, and two cofacial bis-porphyrin interaction sites can be created in orthogonal geometry within the same molecule. The multiporphyrin hosts, termed "twisted, two-faced porphyrins", abbreviated as OxP-(MPx)n where M = 2H or Zn, n = 2 or 4, and x = meta (m) or para (p), and their complexes with a bis-4-pyridyl-substituted fullerene derivative were investigated using spectroscopic, electrochemical, and photochemical methods. Porphyrin fluorescence emission of the OxP-(ZnPx)n compounds is quenched substantially compared to that of pristine ZnP with this quenching being more significant for OxP-(ZnPx)2 than for the OxP-(ZnPx)4. The electrochemically determined highest occupied molecular orbital to lowest unoccupied molecular orbital (HOMO-LUMO) gap for the OxP-(ZnPx)n series is ∼1.65 eV. For the OxP-(ZnPx)n series, charge separation from the singlet excited ZnP to OxP occurs, while, for their complexes with the bis-pyridyl fullerene derivative, charge separation appears to occur predominantly from the singlet excited porphyrin to fullerene.
AB - A new class of multichromophoric host compounds capable of binding guest species through two-point coordinative interaction is reported. The hosts contain appended zinc porphyrin (ZnP) moieties connected covalently by acetylene linkages to a central oxoporphyrinogen (OxP) unit through its central macrocyclic nitrogen atoms. Orientation of the ZnP groups was controlled to some extent by variation of the substitution pattern at the OxP N-substituent. Up to four porphyrin appendages are accommodated, and two cofacial bis-porphyrin interaction sites can be created in orthogonal geometry within the same molecule. The multiporphyrin hosts, termed "twisted, two-faced porphyrins", abbreviated as OxP-(MPx)n where M = 2H or Zn, n = 2 or 4, and x = meta (m) or para (p), and their complexes with a bis-4-pyridyl-substituted fullerene derivative were investigated using spectroscopic, electrochemical, and photochemical methods. Porphyrin fluorescence emission of the OxP-(ZnPx)n compounds is quenched substantially compared to that of pristine ZnP with this quenching being more significant for OxP-(ZnPx)2 than for the OxP-(ZnPx)4. The electrochemically determined highest occupied molecular orbital to lowest unoccupied molecular orbital (HOMO-LUMO) gap for the OxP-(ZnPx)n series is ∼1.65 eV. For the OxP-(ZnPx)n series, charge separation from the singlet excited ZnP to OxP occurs, while, for their complexes with the bis-pyridyl fullerene derivative, charge separation appears to occur predominantly from the singlet excited porphyrin to fullerene.
UR - http://www.scopus.com/inward/record.url?scp=50249087952&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=50249087952&partnerID=8YFLogxK
U2 - 10.1021/jp8028209
DO - 10.1021/jp8028209
M3 - Article
AN - SCOPUS:50249087952
SN - 1932-7447
VL - 112
SP - 10559
EP - 10572
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 28
ER -