| 摘要 |
In one embodiment, the present invention is concerned with novel xanthene compounds selected from those of the formulae <IMAGE> and <IMAGE> wherein each R1 the same or different is alkyl, each R2 the same or different is an electron-withdrawing group having a positive sigma value greater than 0.6, X is <IMAGE> wherein R3 is alkyl, Y is an electron-withdrawing group, n is 0 or 1 and A is an anion. In another embodiment, the present invention is concerned with photographic products and processes employing these xanthene compounds, e.g., as photographic light-screening dyes.
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