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Spectral properties of protonated schiff base porphyrins and chlorins indo ci calculations and resonance raman studies

, : Spectral properties of protonated schiff base porphyrins and chlorins indo ci calculations and resonance raman studies. Journal of the American Chemical Society 106(14): 3950-3958

INDO-CI calculations successfully reproduce the striking changes in optical spectra that occur on protonation of mono- and disubstituted porphyrin, chlorin and bacteriochlorin Schiff base complexes. They ascribe the changes to Schiff base C.dbd.N .pi.* orbitals which drop in energy upon protonation and mix with and perturb the .pi.* orbitals of the macrocycle, a result consistent with resonance Raman data. The perturbation is predicted to affect not only transition energies and intensities but also dipole moment directions. The symmetry of the porphyrin and the substitution site of the chlorin are shown to play an important role, especially in governing whether the lowest energy transition will red shift or blue shift. Blue shifts are calculated for protonation of ketimine and enamine isomers of pyrochlorophyll a (PChl). Comparison with reported optical spectra suggests that PChl .alpha. Schiff base may undergo isomerization upon protonation. Resonance Raman data on CHO, CHNR, CHNHR+ .pi. system, intramolecular H bonding and selective enhancement of .nu.C.dbd.N for those species with a split Soret band. .nu.C.dbd.N is observed with 488.0-nm excitation into the lower-energy Soret and absent for 406.7-nm excitation into the higher-energy Soret, a result predicted by the calculations.

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Briggs, J. A., 1979: The development of irrigated agriculture in Sudan. An account is presented on the climatic conditions in the Sudan, traditional farming in semi-arid conditions, the irrigation potential of the country, and the progress made with irrigation development since the turn of this century.

Floyd, F. X., 1979: A water treatment and reuse program in Riyadh, Saudi Arabia. The water reuse program used at the King Faisal Medical City is described. The King Faisal Medical City is a 250 bed specialist hospital and research center. It is located on a 100 acre campus on the outskirts of Riyadh. As a small city, it has it...

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Gu Y.; Et Al, 1981: The significance of saber sheath trachea in diagnosis of cor pulmonale. Saber-sheath trachea means marked coronal narrowing associated with sagittal widening of intrathoracic trachea (saber-sheath configuration). Clinical and radiographic indices were compared in 60 cor pulmonale patients with saber-sheath tracheal co...

Lemke, A. E., 1977: Optimum temperature for growth of juvenile bluegills. Juvenile bluegills, Lepomis macrochirus (initial wt, 1.8-8.0 g), were individually marked and fed to excess during a 30 day constant temperature test; day length was 16 h. Fish were tested a temperature intervals of from 20 to

Peterson Vern L., 1995: Consequences and risks of postulated atmospheric releases of radionuclides from Rocky Flats. Eos, Transactions, American Geophysical Union: 7, Suppl., Pages 312. 1995.

Wingate Hill, R.; Davis, G. R.; Bowditch, H. G., 1978: Wear of hardfacing treatments applied to shares of tined tillage implements. The wear resistance of six treatments claimed to increase wear life of scarifier shares was measured in a number of field tests. Four of the treatments were hardfacings, two applied by manual electric arc welding and two using an oxy-acetylene wel...

Gardner, V. R., 1944: A new material for blossom thinning, to serve as a sticker, and to reduce transpiration. The Michigan Agric. Expt. Station has developed a new oil-wax emulsion, using vegetable oils with paraffin wax and an emulsifying agent that, when applied to apple and cherry trees in a dilution of 1:100, is non-toxic to foliage and blossoms. Appl...

Sangster J.F.; Craig R.J.; Waddy J.L.; Hetzel P.S.; Mc Phie J.M., 1972: Endo cardial pacing in heart block due to acute myo cardial infarction. Australian & New Zealand Journal of Medicine 2(2): 128-133

Cohen, G., 1968: L' 'isthme' de Bering et ses vicissitudes. Paleogeographie et migrations Sci Prog Paris, 241-248