Structures of the NH tautomers of tetraethylporphyrin and its isocyclic derivative
Vibronic spectra with detailed structure have been recorded in the fluorescence of the NH tautomers of 2,3,12,13-tetraethylporphyrin (TEP), 13',15'-cyclo-13'-methyl-2,3,12-triethylporphyrin (TEPC), and derivatives of these deuterated at the center, which has involved the use of selective laser excitation at 4.2 K. The degrees of polarization have been measured for the individual phonon-free lines. The vibrational structures and /sup 1/H NMR data (two independent methods) have given the structures of the NH tautomers. The short-wave (main) tautomer of TEP has the imine protons on the pyrrole rings containing ethyl substituents, while the long-wave one has them on the pyrrole rings containing protons in the ..beta.. positions. The intensities of the lines relating mainly to vibrations of the ethyl groups are sensitive to the positions of the central protons. A difference from the tetraalkylporphyrins is that the main TEPC tautomer has the central protons positioned on opposite pyrrole rings not linked to the isocycle as being more favored by energy considerations.
- Research Organization:
- Physics Institute, Minsk, USSR
- OSTI ID:
- 5845218
- Journal Information:
- Theor. Exp. Chem. (Engl. Transl.); (United States), Journal Name: Theor. Exp. Chem. (Engl. Transl.); (United States) Vol. 23:2; ISSN TEXCA
- Country of Publication:
- United States
- Language:
- English
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74 ATOMIC AND MOLECULAR PHYSICS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COUPLING
COUPLING CONSTANTS
DEUTERATION
DEUTERIUM
DEUTERIUM COMPOUNDS
EMISSION SPECTROSCOPY
ENERGY LEVELS
EXCITED STATES
FLUORESCENCE SPECTROSCOPY
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN 1
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYPERFINE STRUCTURE
INTERMEDIATE COUPLING
ISOMERS
ISOTOPE EFFECTS
ISOTOPES
ISOTOPIC EXCHANGE
J-J COUPLING
LASER SPECTROSCOPY
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORIENTATION
PORPHYRINS
SPECTRA
SPECTROSCOPY
SPIN ORIENTATION
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
VIBRATIONAL STATES