title: Synthesis and spectroscopic and electrochemical studies of pyrazine- or pyridine-ring-fused tetraazachlorins, bacteriochlorins, and isobacteriochlorins.
abstract: Mixed condensation of tetramethylsuccinonitrile and either 2,3-dicyano-5,6-diethylpyrazine, 2,3-dicyanopyridine, or 3,4-pyridinedicarboximide in the presence of nickel chloride forms novel pyrazine-, 2,3-pyridine-, or 3,4-pyridine-ring-fused tetraazachlorin (TAC), tetraazabacteriochlorin (TABC), and tetraazaisobacteriochlorin (TAiBC) derivatives. All possible structural isomers were separated using repeated thin-layer chromatography and have been investigated by absorption and magnetic circular dichroism spectroscopy. Similarly to previously reported TAC analogues, the TAC and TABC derivatives show large splitting of the Q band, while a single, intense absorption band is observed for the TAiBC derivatives. Although the absorption spectra are practically identical in shape for the separated structural isomers of TACs and TABCs, the Q-band maxima of the TAiBCs depend significantly on their structures. The observed spectroscopic properties were interpreted on the basis of electrochemical data and the results of (time-dependent) DFT calculations.
authors.affiliation: Organic Intermediates and Dyes Institute, B. Sadovaya 1/4, Moscow 123995, Russia.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Makarova
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Dzyuina
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Fukuda
authors.forename: Hironori
authors.initials: H
authors.lastname: Kaneko
authors.forename: Naoaki
authors.initials: N
authors.lastname: Hashimoto
authors.forename: Yuu
authors.initials: Y
authors.lastname: Kikukawa
authors.forename: Nagao
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Evgeny A
authors.initials: EA
authors.lastname: Lukyanets
mesh_terms: D000042:Absorption; D001372:Aza Compounds / Q000737:chemistry*; D002942:Circular Dichroism; D004563:Electrochemistry; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D009584:Nitrogen / Q000737:chemistry; D017319:Photosensitizing Agents / Q000737:chemistry / Q000302:isolation & purification; D011166:Porphyrins / Q000737:chemistry* / Q000302:isolation & purification; D011719:Pyrazines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
chemical_list: D001372:Aza Compounds; D017319:Photosensitizing Agents; D011166:Porphyrins; D011719:Pyrazines; D011725:Pyridines; C452433:bacteriochlorin; C452434:isobacteriochlorin; D009584:Nitrogen; C023666:pyridine