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J . Phys. Chem. 1990, 94, 3376-3379
in all X H bonds. The increase in basis set size from 6-31G* to 6-31 IG** leads to a decrease in all bond lengths.
Conclusion These calculations support the experimental values of Adams, McIntosh, and Smith6 for the proton affinities of PN, PO, PS,
and HCP. Protonation is not favored at the P atom. In order to get theoretical values close to the experimental values, a large basis set. the inclusion of basis set superposition error corrections, and zero-point vibrational energies are necessary. Acknowledgment. I acknowledge the exchange of correspondence with Professor David Smith which stimulated this study.
Photochemical Hole Burning of Porphine in Amorphous Matrices In-Ja Lee, Gerald J . Small, and John M. Hayes* Ames Laboratory, US.Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 5001 I (Receiced: January 9 , 1990)
Polarized hole and antihole spectra for tetraphenylporphine in a polystyrene matrix are presented. It is shown that, consistent with the photochemical nature of the hole, the antihole is polarized oppositely to the hole and is distributed throughout the inhomogeneous distribution of absorbers. However, there is also a pronounced asymmetry of the antihole which is interpreted as being due to the amorphous nature of the lattice. A correlation between the site energy distribution functions for the Q, and Q, states is also demonstrated
Introduction It is well-known from N M R studies of porphine solutions that these molecules undergo facile tautomerization involving a double proton transfer.1,2 Although the dark ground-state processes monitored by N M R cease at cryogenic temperatures, the tautomerization can still occur photochemically, even at temperatures
