Protonation of some non-transition metal phthalocyanines — spectral and photophysicochemical consequences

The photophysics and photochemistry of phthalocyanine complexes of magnesium (MgPc), aluminum chloride (ClAlPc) and zinc (ZnPc) are studied in N,N′-dimethylformamide (DMF). The values obtained for the photophysical and photochemical parameters are normal for simple metallophthalocyanine (MPc) complexes. Protonation of the azomethine bridges reduced the photoactivities of the complexes considerably; however the excited triplet states of the protonated species are more stable towards ground state oxygen. The interaction of the non-protonated MPcs with ground state oxygen is shown to be diffusion-assisted, with bimolecular rate constant values of the order of 1010 M-1.s-1. MgPc could not be protonated; it was easily demetalated by the protonating acid. The kinetics of the demetalation yielded the rate equation: Rate = 0.1[MgPc][H+]2/3

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ChemInform Abstract: Electron Transfer from Ground-State Triethylamine to the Second and Lowest Excited Triplet States of Haloanthraquinones (1-Chloro, 2- Chloro, 1,5-Dichloro, 1,8-Dichloro, and 1,8-Dibromo Compounds) in Acetonitrile at Room Temperature S

ChemInform ◽

10.1002/chin.199233101 ◽

2010 ◽

Vol 23 (33) ◽

pp. no-no

Author(s):

K. HAMANOUE ◽

T. NAKAYAMA ◽

S. ASADA ◽

K. IBUKI

Keyword(s):

Electron Transfer ◽

Ground State ◽

Room Temperature ◽

Triplet States ◽

Excited Triplet ◽

Excited Triplet States

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Electron transfer from ground-state triethylamine to the second and lowest excited triplet states of haloanthraquinones (1-chloro, 2-chloro, 1,5-dichloro, 1,8-dichloro, and 1,8-dibromo compounds) in acetonitrile at room temperature studied by picosecond and nanosecond laser spectroscopy

The Journal of Physical Chemistry ◽

10.1021/j100188a033 ◽

1992 ◽

Vol 96 (9) ◽

pp. 3736-3741 ◽

Cited By ~ 13

Author(s):

Kumao Hamanoue ◽

Toshihiro Nakayama ◽

Satoshi Asada ◽

Kazuyasu Ibuki

Keyword(s):

Electron Transfer ◽

Laser Spectroscopy ◽

Ground State ◽

Room Temperature ◽

Nanosecond Laser ◽

Triplet States ◽

Excited Triplet ◽

Excited Triplet States

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Monitoring the Formation and Decay of Transient Photosensitized Intermediates Using Pump-Probe UV Resonance Raman Spectroscopy. I: Self-Modeling Curve Resolution

Applied Spectroscopy ◽

10.1366/00037020360625989 ◽

2003 ◽

Vol 57 (4) ◽

pp. 439-447 ◽

Cited By ~ 4

Author(s):

James A. Kleimeyer ◽

Joel M. Harris

Keyword(s):

Factor Analysis ◽

Excited State ◽

Ground State ◽

Pure Component ◽

Triplet States ◽

Time Resolved ◽

Pump Probe ◽

Excited Triplet ◽

Curve Resolution ◽

Excited Triplet States

Resolution of transient excited-state Raman scattering from ground-state and solvent bands is a challenging spectroscopic measurement since excited-state spectral features are often of low intensity, overlapping the dominant ground-state and solvent bands. The Raman spectra of these intermediates can be resolved, however, by acquiring time-resolved data and using multidimensional data analysis methods. In the absence of a physical model describing the kinetic behavior of a reaction, resolution of the pure-component spectra from these data can be accomplished using self-modeling curve resolution, a factor analysis technique that relies on the correlation in the data along a changing composition dimension to resolve the component spectra. A two-laser UV pump-probe resonance-enhanced Raman instrument was utilized to monitor the kinetics of amine quenching of excited-triplet states of benzophenone. The formation and decay of transient intermediates were monitored over time, from 15 ns to 100 μs. Factor analysis of the time-resolved spectral data identified three significant components in the data. The time-resolved intensities at each Raman wavenumber shift were projected onto the three significant eigenvectors, and least-squares criteria were developed to find the common plane in the space of the eigenvectors that includes the observed data. Within that plane, the three pure-component spectra were resolved using geometric criteria of convex hull analysis. The resolved spectra were found to arise from benzophenone excited-triplet states, diphenylketyl radicals, and the solvent and ground-state benzophenone.

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Electron transfer from ground-state triethylamine to the lowest excited triplet states of chloroanthraquinones (the 1-chloro, 2-chloro, 1,5-dichloro and 1,8-dichloro compounds) in ethanol and toluene at room temperature

Journal of the Chemical Society Faraday Transactions ◽

10.1039/ft9918703731 ◽

1991 ◽

Vol 87 (23) ◽

pp. 3731 ◽

Cited By ~ 10

Author(s):

Kumao Hamanoue ◽

Toshihiro Nakayama ◽

Kazuyasu Ibuki ◽

Akira Otani

Keyword(s):

Electron Transfer ◽

Ground State ◽

Room Temperature ◽

Triplet States ◽

Excited Triplet ◽

Excited Triplet States

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Geometries of the ground and first excited triplet states of thioformaldehyde

Canadian Journal of Chemistry ◽

10.1139/v81-468 ◽

1981 ◽

Vol 59 (22) ◽

pp. 3200-3203 ◽

Cited By ~ 10

Author(s):

John D. Goddard

Keyword(s):

Ground State ◽

Reasonable Agreement ◽

Basis Sets ◽

Triplet States ◽

Gaussian Basis Sets ◽

Excited Triplet ◽

Polarization Functions ◽

Scf Calculations ◽

Split Valence ◽

Excited Triplet States

The geometries of the S0 and T1 states of thioformaldehyde are determined by ab initio SCF calculations with Gaussian basis sets ranging from minimal to double ζ plus both diffuse and polarization functions. The ground state geometries are all in reasonable agreement with experiment but for the n → π* triplet state split valence or double ζ basis sets yield unreasonably long CS bond distances.

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