Unsymmetric leuco-TAM dyes, (2E, 2鈥?span style='font-style: italic'>E)-2,2鈥?{(E)-4-phenylpent-2-ene-1,5-diylidene}bis(1,3,3-trimethylindoline) derivatives. Part II: X-ray crystal structure
- 作者：Sam-Rok Keum ; keum@korea.ac.kr ; So-Young Ma ; Do-Kyung Kim ; Hyun-Woo Lim ; Se-Jung Roh
- 关键词：Unsymmetrical leuco-TAM ; Unsymmetric three-bladed propeller conformation ; EEE isomers ; Stereoselective formation ; Near-IR dyes ; Cy5 TAM+ dye
- 刊名：Dyes and Pigments
- 出版年：2012
- 期刊代码：31_01437208
- 类别：ms
- 出版时间：September, 2012
- 卷：94
- 期：3
- 页码：490-495
- 文件大小：615 K
摘要
The unequivocal solid-state structure and stereochemistry of the unsymmetric leuco-triarylmethane (Un-LTAM) dye 2,2鈥?{(E)-4-(phenyl)pent-2-ene-1,5-diylidene}bis(1,3,3-trimethylindoline) derivatives were established using X-ray single-crystal analysis. The X-ray analysis showed that the EEE isomers were formed stereoselectively with an unsymmetric three-bladed propeller conformation from the reaction of a Fischer's base and cinnamaldehyde derivatives. The 5,5鈥?dichloro-4鈥?nitro-triarylmethane dye displayed a triclinic crystal structure with the space group P-1. The molecules stack alternately to form a dimer, adopting intermolecular distances of 8.53 and 9.40 脜 for rings B and C, respectively. Unsymmetric triarylmethane cations, the oxidized form of these dyes, have UV absorptions over 680 nm and selected examples absorb close to the near-IR region.