TY - JOUR
T1 - Investigation of the photoinduced axial ligation process in the excited state of nickel(II) phthalocyanine
AU - Hong, Jiyun
AU - Fauvell, Thomas J.
AU - Helweh, Waleed
AU - Zhang, Xiaoyi
AU - Chen, Lin X.
N1 - Funding Information:
We acknowledge support for this work from the Solar Energy Photochemistry program of the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences , through Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Use of the Advanced Photon Source (APS) at Argonne National Laboratory is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.
Publisher Copyright:
© 2018
PY - 2019/3/1
Y1 - 2019/3/1
N2 - Photoinduced axial ligation process in the excited state of nickel(II) octabutoxyphthalocyanine (NiPcOBu8) in pyridine solvent has been investigated by ultrafast optical transient absorption and X-ray transient absorption spectroscopies. Although Ni phthalocyanine complexes have been reported to have no tendency to form six-coordinate structure, the (dz2,dx2-y2) state of NiPcOBu8 generated by photoexcitation of Q-band was discovered to axially ligate with the pyridine molecule very rapidly, on a timescale of ˜100 ps. Although the presence of an excited unligated (d,d) state cannot be confirmed due to the time resolution limit of the synchrotron X-ray probe pulse with ˜80 ps FWHM, the biexponential kinetics of the ground state recovery detected by the 1s → 4pz feature suggests the decay of the unligated (d,d) species with an 82 ps time constant, while that of the ligated NiPcOBu8 species is 3–5 ns. The photoinduced ligation dynamics of NiPcOBu8 is vastly different compared to that of Ni porphyrin complexes. This study provides a structural basis on the ligation chemistry in both the ground and excited states of nickel complexes based on their electronic and nuclear structures.
AB - Photoinduced axial ligation process in the excited state of nickel(II) octabutoxyphthalocyanine (NiPcOBu8) in pyridine solvent has been investigated by ultrafast optical transient absorption and X-ray transient absorption spectroscopies. Although Ni phthalocyanine complexes have been reported to have no tendency to form six-coordinate structure, the (dz2,dx2-y2) state of NiPcOBu8 generated by photoexcitation of Q-band was discovered to axially ligate with the pyridine molecule very rapidly, on a timescale of ˜100 ps. Although the presence of an excited unligated (d,d) state cannot be confirmed due to the time resolution limit of the synchrotron X-ray probe pulse with ˜80 ps FWHM, the biexponential kinetics of the ground state recovery detected by the 1s → 4pz feature suggests the decay of the unligated (d,d) species with an 82 ps time constant, while that of the ligated NiPcOBu8 species is 3–5 ns. The photoinduced ligation dynamics of NiPcOBu8 is vastly different compared to that of Ni porphyrin complexes. This study provides a structural basis on the ligation chemistry in both the ground and excited states of nickel complexes based on their electronic and nuclear structures.
KW - Excited state structural dynamics
KW - Photochemistry
KW - Phthalocyanines
KW - Ultrafast optical transient absorption
KW - X-ray transient absorption spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85059194871&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85059194871&partnerID=8YFLogxK
U2 - 10.1016/j.jphotochem.2018.12.026
DO - 10.1016/j.jphotochem.2018.12.026
M3 - Article
AN - SCOPUS:85059194871
SN - 1010-6030
VL - 372
SP - 270
EP - 278
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
ER -