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This review focuses on classifying different types of long wavelength absorbing BODIPY dyes based on the wide range of structural modification methods that have been adopted, and on tabulating their spectral and photophysical properties. The structure-property relationships are analyzed in depth with reference to molecular modeling calculations, so that the effectiveness of the different structural modification strategies for shifting the main BODIPY spectral bands to longer wavelengths can be readily compared, along with their effects on the fluorescence quantum yield (ΦF) values. This should facilitate the future rational design of red/NIR region BODIPY dyes for a wide range of different applications.

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The first magnetic circular dichroism (MCD) spectra are reported for tetraphenyltetraacenaphthoporphyrin (TPTANP). The impact on the electronic structure of steric interactions between the fused acenaphthalene rings and the meso-tetraphenyl substituents is explored based on an analysis of the optical spectra of the Zn(II) complex (ZnTPTANP) and the free base dication species ([H4TPTANP]2+). In the case of ZnTPTANP, significant folding of the porphyrinoid ligand induces a highly unusual MCD-sign reversal providing the first direct spectroscopic evidence of ligand nonplanarity. Density functional theory (DFT) geometry optimizations for a wide range of Zn(II) porphyrinoids based on the B3LYP functional and TD-DFT calculations of the associated UV-visible absorption spectra are reported, allowing a complete assessment of the MCD data. TPTANP complexes are found to fall into a class of cyclic polyenes, termed as soft MCD chromophores by Michl (J. Pure Appl. Chem. 1980, 52, 1549.), since the signs of the Faraday A1 terms observed in the MCD spectrum are highly sensitive to slight structural changes. The origin of an unusually large red shift of the main B (or Soret) band of MTPTANP (the most red shifted ever reported for fused-ring-expanded metal porphines) and of similar red shifts observed in the spectra of other peripherally crowded porphyrinoid complexes is also explored and explained on this basis.

The synthesis and spectroscopic properties of a series of boron-free meso-aryl-substituted [14]triphyrin(2.1.1) compounds containing either peripheral bicyclo[2.2.2]octadiene (BCOD) (2a−c) or benzene rings (3a−c) (aryl = phenyl a, 4-fluorophenyl b, and 4-methylbenzoatephenyl c) are reported. These compounds represent the first examples of free-base contracted porphyrinoids with 14 π-electron aromatic systems containing only the standard pyrrole and isoindoline moieties of the porphyrins and tetrabenzoporphyrins.

The application of the UV/H 2 O 2 process to the degradation of methyl tert-butyl ether (MTBE) in dilute aqueous solution resulted in the generation of tert-butyl formate (TBF), 2-methoxy-2-methyl propionaldehyde (MMP), formaldehyde, acetone, tert-butyl alcohol (TBA), and methyl acetate as primary byproducts. Other intermediates, such as carbonyl compounds (hydroxy-iso-butyraldehyde, hydroxyacetone, pyruvaldehyde) and organic acids (hydroxy-iso-butyric, formic, pyruvic, acetic, oxalic) were also detected and quantified during the irradiation. A good organic carbon balance is obtained throughout the treatment, indicating that almost all of the intermediates have been detected. The TOC pattern shows that eventually all the organic compounds are mineralized. Various analytical techniques, such as GC/MS, GC, IC, HPLC, and TOC analysis, were employed in order to identify and quantify the organic products. The detailed reaction mechanism proposed in this study for the degradation of MTBE by • OHdriven oxidation processes accounts for all observed intermediates and the high oxygen demand required for their complete mineralization.

The approach developed previously to assign the major π → π* and π* → π* bands in the optical spectra of metallophthalocyanine radical species [ MPc (−n)](n−2)− (n = 1–6), which was based on spectral band deconvolution analyses of the UV-vis absorption and magnetic circular dichroism (MCD) spectra and ZINDO calculations, is reviewed in this paper and extended to the major bands observed in the spectrum of the zinc tetraphenylporphyrin radical anion [ ZnTPP (−3)]−. The magnetic circular dichroism spectrum is dominated by an intense pseudo A term associated with the B (or Soret) transition with bands at 445 and 465 nm. Weaker bands associated with the π* → π* transition out of the partially filled LUMO give rise to two widely separated, oppositely signed, coupled B terms in the MCD spectrum at 538 and 910 nm. The Q transition is assigned to a weak absorption band at 750 nm and a shoulder slightly to the blue at 728 nm.