Synthesis, Reactivity, and Spectroscopic Properties of meso-Triaryl-5-oxaporphyrins

• Published in: Journal of organic chemistry Vol. 77; no. 15; pp. 6510 - 6519
• Main Authors: Kakeya, Kazuhisa, Nakagawa, Aya, Mizutani, Tadashi, Hitomi, Yutaka, Kodera, Masahito
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03-08-2012
• Subjects: Chemical reactivity; Chemistry; Crystallography, X-Ray; Exact sciences and technology; General and physical chemistry; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Kinetics and mechanisms; Models, Molecular; Molecular Structure; Organic chemistry; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Porphyrins - chemistry; Preparations and properties; Quantum Theory; Reactivity and mechanisms; Solubility; Solutions; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Zinc - chemistry; Water; Nitrogen heterocycle; Zinc complex; Fluorescence; Alcohol; Propan-2-ol; Oxygen heterocycle; Pyrrole derivatives; Anions; Methyl sulfoxide; Steric effect; Chlorocarbon; 2-Methyl-propan-2-ol; Ethyl ether; Chemical reactivity; Chemical synthesis; Methanol; Chloroform; Ethanol; Zinc II; Toluene; Solubility; Steric hindrance; Transition metal Complexes; Quantum yield; Reaction rate; Acetic acid ethyl ester; X ray diffraction; Acetic anhydride; Zinc II Compounds; Organic solvent; Zinc Acetate; Fluorescence yield; N,N-Dimethylformamide; Acetonitrile; Spectrophotometry; Porphyrin derivatives; Room temperature; Acetone; Ultraviolet visible spectrometry; Crystalline structure
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo3010342

[meso-Triaryl-21,23-didehydro-23H-5-oxa­porphyrinato](trifluoroacetato)zinc(II) was prepared by the reaction of meso-triarylbilindione with acetic anhydride and zinc acetate, and it was isolated as a trifluoroacetate salt. The X-ray crystallographic study demonstrated that the trifluoroacetate anion was coordinated to the zinc ion. [21,23-Didehydro-10,15,20-tris(4-methoxycarbonylphenyl)-23H-5-oxaporphyrinato](trifluoroacetato)zinc(II) 3a was dissolved in various organic solvents such as toluene, chloroform, diethyl ether, ethyl acetate, acetone, acetonitrile, methanol, DMSO, and DMF, although it readily reacted with alcohols and DMF to yield linear tetrapyrroles. The solubility of 3a in toluene was 4.2 ± 0.1 g dm–3 at room temperature. 3a showed characteristic UV–vis absorption at 649 nm and fluorescence emission at 657 nm in chloroform. The fluorescence quantum yields of 3a, [21,23-didehydro-10,15,20-triphenyl-23H-5-oxaporphyrinato](trifluoroacetato)zinc(II) (3c), and [21,23-didehydro-10,15,20-tris(4-methoxyphenyl)-23H-5-oxaporphyrinato](trifluoroacetato)zinc(II) (3b) were 0.071, 0.071, and 0.050, respectively. Reaction of 3a with EtOH afforded the zinc complex of 19-ethoxybilinone, and it proceeded 2 orders of magnitude faster than that of [β-octaalkyl-21,23-didehydro-23H-5-oxaporphyrinato]zinc(II). The reaction with alcohols was sensitive to steric bulk of the alcohols; the rate of reaction with i-PrOH was 2700 times faster than that of t-BuOH at 303 K. The reaction of [meso-triaryl-21,23-didehydro-23H-5-oxaporphyrinato]zinc(II) with water proceeded 3 orders of magnitude slower than that with EtOH.