Spectroscopic Studies on Dyes. I. The Association of Indigo Dyes in the Solid Phase1
Spectroscopic Studies on Dyes. I. The Association of Indigo Dyes in the Solid Phase1
复制标题
染料的光谱研究。
DOI：
10.1021/ja01592a012
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发表时间：
1956
影响因子：
15
通讯作者：
G. Wyman
中科院分区：
文献类型：
--
作者：
J. Weinstein;G. Wyman
靛蓝及其7个烷基和卤素取代的衍生物的可见光谱测定在固相颗粒在溴化钾和水悬浮液。将固体光谱与溶液光谱进行比较，发现靛蓝的第一吸收带发生了强烈的红移。在4-和7-位引入甲基或氯取代基被发现降低这种位移的幅度。在5，5 ′，7，7 ′-四溴靛中没有观察到这种位移。根据这些观察，可以得出结论，在固态下，靛蓝染料可能通过氢键结合。在4，4 ′-或7，7 ′-位上的大取代基阻止了相邻分子的-CO-和-NH-基团的接近，从而干扰了分子聚集体的形成。这些染料在-CO-和-NH-伸缩区域的红外光谱的研究也支持这一解释。用靛蓝染色的玻璃纸和明胶薄膜的吸收光谱表明，在这些条件下靛蓝也以缔合形式存在。
The visible spectra of indigo and seven of its alkyl-and halogen-substituted derivatives were determined in the solid phase as pellets in potassium bromide and also as aqueous suspensions. The first absorption band of indigo was found to ex-hibit a strong bathochromic shift when the solid spectrum was compared with that obtained in solution. The introduction of methyl or chlorine substituents in the 4-and 7-positions was found to decrease the magnitude of this shift. No such shift was observed in 5, 5', 7, 7'-tetrabromoindigo. On the basis of these observations it was concluded that, in the solid state, indigo dyes are associated, probably by means of hydrogen-bonding. Bulky substituents in the 4, 4'-or 7, 7'-positions prevent the close approach of the-CO-and-NH-groups of neighboring molecules and thusinterfere with the formation of molecular aggregates. A study of the infrared spectra of these dyes in the-CO-and-NH-stretching regions also supports this explanation. The absorption spectra of cellophane and gelatin films dyed with indigo indicate that under these conditions indigo is also present in the associated form.