Continuous Symmetry Breaking Induced by Ion Pairing Effect in Heptamethine Cyanine Dyes: Beyond the Cyanine Limit
Continuous Symmetry Breaking Induced by Ion Pairing Effect in Heptamethine Cyanine Dyes: Beyond the Cyanine Limit
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DOI：
10.1021/ja9100886
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发表时间：
2010-03-31
影响因子：
15
通讯作者：
Maury, Olivier
中科院分区：
文献类型：
--
作者：
Bouit, Pierre-Antoine;Aronica, Christophe;Maury, Olivier
实现了七甲川菁阳离子1（+）与各种抗衡离子A（A = Br-，I-，PF 6-，SbF 6-，B（C6 F5）（4）（-），TRISPHAT）的缔合。六种不同的离子对已通过X-射线衍射进行了表征，并研究了它们在极性（DCM）和非极性（甲苯）溶剂中的吸收特性。一个小的，硬的阴离子（Br-）是能够强烈地取代聚甲炔链，导致在晶体中的非对称偶极样结构的稳定和非解离溶剂。相反，在极性更强的溶剂中或当它与大体积软阴离子（TRISPHAT或B（C6 F5）（4）（-））缔合时，相同的花青染料优先采用理想的多甲川态。因此，七甲川染料的固态和溶液吸收性质与其所含的配合物的性质密切相关。
The association of heptamethine cyanine cation 1(+) with various counterions A (A = Br-, I-, PF6-, SbF6-, B(C6F5)(4)(-), TRISPHAT) was realized. The six different ion pairs have been characterized by X-ray diffraction, and their absorption properties were studied in polar (DCM) and apolar (toluene) solvents. A small, hard anion (Br-) is able to strongly polarize the polymethine chain, resulting in the stabilization of an asymmetric dipolar-like structure in the crystal and in nondissociating solvents. On the contrary, in more polar solvents or when it is associated with a bulky soft anion (TRISPHAT or B(C6F5)(4)(-)), the same cyanine dye adopts preferentially the ideal polymethine state. The solid-state and solution absorption properties of heptamethine dyes are therefore strongly correlated to the nature of the counterion.