TY - JOUR
T1 - Effect of central metal substitution on linear dichroism of porphyrins
T2 - Evidence of out-of-plane transition moments
AU - Gryczynski, Zygmunt
AU - Paolesse, Roberto
AU - Smith, Kevin M.
AU - Bucci, Enrico
N1 - Funding Information:
This work was supported in part by PHS NIH * “rant POI-HL-485 17. HL-X25:! and RR-08 I 19 to the Center for Fluorescence Spectroscopy. Computer time and facilities were supported in part by the computer network of the University of Maryland at Baltimore. and College Park. MD.
PY - 1997/11
Y1 - 1997/11
N2 - Absorption anisotropy and emission anisotropy measurements in poly(vinyl) alcohol (PVA) films of different porphyrin derivatives are reported. Wavelength dependent absorption anisotropy in oriented PVA films, and wavelength dependent excitation spectrum of emission anisotropy of fluorescent porphyrin derivatives in isotropic PVA films indicate the presence of multiple transition moments with different well-defined orientation. Comparison of linear dichroism and orientation behavior in stretched PVA films of deuteroporphyrin III (C(2V) symmetry) and its iron derivative reveals significant out-of-plane transition moment components. A considerable participation of out-of-plane polarized absorption components is also observed for metal derivatives of non-symmetrical protoporphyrin IX. It appears that central metal substitutions in porphyrin rings do not produce 'circular' degeneration of electronic transition moments. Instead, the presence of metal induces absorption components orthogonal to the porphyrin plane.
AB - Absorption anisotropy and emission anisotropy measurements in poly(vinyl) alcohol (PVA) films of different porphyrin derivatives are reported. Wavelength dependent absorption anisotropy in oriented PVA films, and wavelength dependent excitation spectrum of emission anisotropy of fluorescent porphyrin derivatives in isotropic PVA films indicate the presence of multiple transition moments with different well-defined orientation. Comparison of linear dichroism and orientation behavior in stretched PVA films of deuteroporphyrin III (C(2V) symmetry) and its iron derivative reveals significant out-of-plane transition moment components. A considerable participation of out-of-plane polarized absorption components is also observed for metal derivatives of non-symmetrical protoporphyrin IX. It appears that central metal substitutions in porphyrin rings do not produce 'circular' degeneration of electronic transition moments. Instead, the presence of metal induces absorption components orthogonal to the porphyrin plane.
UR - http://www.scopus.com/inward/record.url?scp=0031449416&partnerID=8YFLogxK
U2 - 10.1016/S0301-4622(97)00077-X
DO - 10.1016/S0301-4622(97)00077-X
M3 - Article
C2 - 9440210
AN - SCOPUS:0031449416
SN - 0301-4622
VL - 69
SP - 71
EP - 84
JO - Biophysical Chemistry
JF - Biophysical Chemistry
IS - 1
ER -