Hydroxyl Radical as a Probe of the Charge Distribution in Aromatics: Phenol
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- 作者：Guadalupe Albarran ; Robert H. Schuler
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：April 5, 2007
- 年：2007
- 卷：111
- 期：13
- 页码：2507 - 2510
- 全文大小：170K
- 年卷期：v.111,no.13(April 5, 2007)
- ISSN：1520-5215
文摘
Initial radiation chemical yields of 1.48 (2), 0.24 (2), and 2.01 molecules per 100 eV of absorbed energy arereported for addition of 
OH radical to each of the ortho, meta, and para positions of phenol. These yieldsrepresent 91% of the yield of 5.96 expected for OH addition to 5 mM phenol and are in general agreementwith other previous measurements. Pulse radiolysis experiments show that phenoxy radical is produced in ayield of ~0.42 as a result of addition of OH at phenol's ipso position. The total of these yields (5.84) accountsfor the addition of virtually all of the expected OH radicals. The relative yields for addition to the ortho,meta, and para positions provide a measure of the charge distribution in phenol that correlates quite well withthe unpaired spin distribution in phenoxyl radical. This correlation indicates that the OH substituent similarlyaffects the charge distribution on the aromatic ring of phenol and the unpaired spin distribution in the phenoxylradical.
OH radical to each of the ortho, meta, and para positions of phenol. These yieldsrepresent 91% of the yield of 5.96 expected for OH addition to 5 mM phenol and are in general agreementwith other previous measurements. Pulse radiolysis experiments show that phenoxy radical is produced in ayield of ~0.42 as a result of addition of OH at phenol's ipso position. The total of these yields (5.84) accountsfor the addition of virtually all of the expected OH radicals. The relative yields for addition to the ortho,meta, and para positions provide a measure of the charge distribution in phenol that correlates quite well withthe unpaired spin distribution in phenoxyl radical. This correlation indicates that the OH substituent similarlyaffects the charge distribution on the aromatic ring of phenol and the unpaired spin distribution in the phenoxylradical.