| 摘要 |
A compound is represented by Formula (1):
wherein, each X is independently oxygen, sulfur, or selenium; m is 0 or 1; each n is independently 0 or 1; R 1 - R 3 are each independently, for example, hydrogen or alkyl having 1 to 20 carbons;
wherein
(i) in the case of m = 0, it is excluded that all of R 1 - R 3 are hydrogen at the same time;
(ii) in the case of m = 0, n = 0 and in the case that m is 0, one of n is 0 and the other is 1, it is excluded that "both of X are sulfur and all R 3 s are the same atoms or groups at the same time";
(iii) in the case of m = 0, n = 1, it is excluded that all R 3 s are the same atoms or groups at the same time, and at least one of R 3 s is hydrogen. |
