Investigation of the Photoinduced axial ligation process in the excited state of nickel (II) phthalocyanine
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 sixcoordinate structure, the (d(z2),d(x2-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 (similar to)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 (similar to)80 ps FWHM, the biexponential kinetics of the ground state recovery detected by the is 1s -> 4pz feature suggests the decay of the unligated (d,d) species with an 82ps 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.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science - Office of Basic Energy Sciences - Chemical Sciences, Geosciences, and Biosciences Division
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1641748
- Journal Information:
- Journal of Photochemistry and Photobiology. A, Chemistry, Vol. 372
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photodynamics of nickel porphyrins in noncoordinating solvents: characterization of d-d excited states using transient raman spectroscopy
Laser-induced excited-state ligation changes for nickel tetraphenylporphine monitored by Raman spectroscopy