| Autor: |
Stulz, Eugen, Maue, Michael, Scott, Sonya M., Mann, Brian E., Sanders, Jeremy K. M. |
| Zdroj: |
New Journal of Chemistry; 2004, Vol. 28 Issue: 8 p1066-1072, 7p |
| Abstrakt: |
Primary alkynyl phosphine porphyrins were prepared by AlHCl2reduction of the corresponding alkynyl phosphonates. Dephosphorylation of the alkyne proved to be a major side reaction. Using LiAlH4as reducing agent, the alkyne was found to be partially reduced to give the trans-alkenyl phosphine selectively. The primary phosphines coordinate to both rutheniumii and rhodiumiii porphyrins and readily form bis-phosphine complexes. The 1H and 31P NMR spectra for the ruthenium complexes show a pattern characteristic of an AX22spin system with an unusually large 2JPPcoupling constant of 620.6 Hz. The IR spectrum of the complex PAPH2RuCOporphyrin PAPH2 phenylacetylenephosphine indicates weak σ-donor properties of the ligand. In contrast to the corresponding tertiary phosphine complexes, the bis-phosphine complexes with both rutheniumii and rhodiumiii porphyrins are more stable than the mono-phosphine complexes, as judged by NMR spectroscopy, and they can also be detected in the gas phase by LDI-TOF MS. In all cases the complexes could not be isolated and they degrade within hours at ambient temperatures when kept in solution. These compounds may therefore not be suitable for the construction of larger multiporphyrin systems, but their accessibility makes it possible to study their coordination behaviour with other transition metals. |
| Databáze: |
Supplemental Index |
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