| 摘要 |
<p>Benzo- 2 -pyrans New cpds. which are sensitive to irradiation and used to eradiate signals in data-storage assemblies. The spiro-cpds (I) where Ar and/or Ar' are opt substd aromatic, and R and/or R' are opt satd opt branched opt substd. alkyl, H or opt substd aromatic. are more stable than cpds previously used and the decolorisation produced is irreversible.</p> |
