- Molecular structure, UV/vis spectra, and cyclic voltammograms of Mn(II), Co(II), and Zn(II) 5,10,15,20-tetraphenyl-21-oxaporphyrins
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The 5,10,15,20-tetraphenyl-21-oxaporphyrin complexes of Mn(II), Co(II), and Zn(II) have been crystallized and studied by X-ray diffraction, NMR and UV/vis spectroscopy, and mass spectrometry as well as cyclic voltammetry. The X-ray structure of the earlier described Cu(II) complex is also reported. All complex structures possess a five-coordinate, approximately square-pyramidal geometry with a slight deviation of the heteroaromatic moieties from planarity. The packing structures are characterized by parallel strands of complex molecules interacting by weak hydrogen bonds. In the case of Zn(II) an octahedral complex has also been isolated using a side-chain hydroxy functionalized oxaporphyrin ligand; the structure was verified by NMR and EXAFS spectroscopy. Cyclic voltammetry studies reveal that the reduction of the complex bound Mn(II), Co(II), and Zn(II) ions is a ligand-centered process whereas the first oxidation step depends on the metal ion present.
- Gloe, Karsten,Stute, Silvio,G?tzke, Linda,Meyer, Dirk,Merroun, Mohamed L.,Rapta, Peter,Kataeva, Olga,Seichter, Wilhelm,Gloe, Kerstin,Dunsch, Lothar
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p. 1515 - 1524
(2013/04/10)
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- Continuous preparation of arylmagnesium reagents in flow with inline IR monitoring
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A newly developed microscale ReactIR flow cell was used as a convenient and versatile inline analytical tool for Grignard formation in continuous flow chemical processing. The LiCl-mediated halogen/Mg exchange reaction was used for the preparation of functionalized arylmagnesium compounds from aryl iodides or bromides. Furthermore, inline IR monitoring was used for the analysis of conversion and possible byproduct formation, as well as a potential tool for elucidation of mechanistic details. The results described herein indicate that the continuous flow systems are effective for highly exothermic reactions such as the Grignard exchange reaction due to fast mixing and efficient heat transfer.
- Brodmann, Tobias,Koos, Peter,Metzger, Albrecht,Knochel, Paul,Ley, Steven V.
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experimental part
p. 1102 - 1113
(2012/08/27)
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- One-flask synthesis of mono- and trifunctionalized 21-thia and 21-oxaporphyrin building blocks and their application in the synthesis of covalent and noncovalent unsymmetrical porphyrin arrays
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A rapid synthetic route has been developed to synthesize mono- and trifunctionalized 21-thia and 21-oxaporphyrin systems using simple precursors such as 2[α-(aryl)-α-hydroxvmethyl] thiophene (thiophene mono-ol) and 2[α-(aryl)-α-hydroxvmethyl] furan (furan mono-ol), respectively. Condensation of one equivalent of thiophene or furan mono-ol with two equivalents of aryl aldehyde and three equivalents of pyrrole under porphyrin forming conditions followed by column chromatography resulted in functionalized 21-thia or 21-oxaporphyrins. To synthesize monofunctionalized porphyrins, the mono-ol containing the functionalized aryl group was used. The functionalized aldehydes were used to synthesize trifunctionalized porphyrins. The mono-ol method is versatile and applicable to synthesize mono- and trifunctionalized 21-thia and 21-oxaporphyrins containing functional groups such as iodophenyl, ethynylphenyl, hydroxyphenyl, bromophenyl, and pyridyl groups. The monofunctionalized porphyrin building blocks containing iodophenyl and ethynylphenyl groups were used further to synthesize four unsymmetrical covalent porphyrin dimers containing two different porphyrin cores such as N 3S-N4, N3O-N4, and N 3S-N3O bridged via diaryl ethyne group and one symmetrical phenylethyne bridged dimer containing two N3S cores. A preliminary photophysical study on these dimers indicated a possibility of energy transfer from one subunit to another. We also demonstrated the use of trifunctionalized porphyrins in the synthesis of two noncovalent unsymmetrical porphyrin tetramers containing one N3S and three N4 porphyrin subunits.
- Gupta, Iti,Ravikanth, Mangalampalli
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p. 6796 - 6811
(2007/10/03)
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- Rational Synthesis of Trans-Substituted Porphyrin Building Blocks Containing One Sulfur or Oxygen Atom in Place of Nitrogen at a Designated Site
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The use of heteroatom-substituted porphyrins in bioorganic and materials chemistry requires the ability to position a variety of substituents in a controlled manner about the porphyrin periphery. We describe a rational route to trans-AB2C-type
- Cho, Won-Seob,Kim, Han-Je,Littler, Benjamin J.,Miller, Mark A.,Lee, Chang-Hee,Lindsey, Jonathan S.
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p. 7890 - 7901
(2007/10/03)
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