三联吡啶化合物的溶剂致荧光变色及丁醇异构体鉴别

在三联吡啶分子中引入N,N-二甲基官能团, 实现了三联吡啶分子的局部激发态发光. 研究发现, 溶剂的极性诱导三联吡啶的偶极矩发生变化, 实现了从深蓝光(λ_max=384 nm)到黄光(λ_max=558 nm)的溶剂致荧光变色. 由于三联吡啶的荧光易受醇溶剂中—OH基团振荡猝灭, 不同空间位阻的正丁醇、 异丁醇、 仲丁醇及叔丁醇溶剂使得三联吡啶发光光色相近, 但发光强度的差异较大. 三联吡啶进一步与ZnCl₂配位得到了三联吡啶-Zn(Ⅱ)配合物, 金属离子Zn(Ⅱ)的配位作用促进了三联吡啶分子内电荷转移. 由于电子给体N,N-二甲基官能团可发生平面扭曲, 丁醇异构体可调节三联吡啶-Zn(Ⅱ)的局部激发态和扭曲分子内电荷转移发光, 进而实现其在丁醇异构体溶剂中发光光色的调节. 因此, 三联吡啶和三联吡啶-Zn(Ⅱ)具有良好的溶剂致荧光变色性能, 可应用于4种丁醇异构体的鉴别.

Highly Solvatochromic Terpyridine Compounds for Identification of Butanol Isomers

N，N-Dimethyl functional group was introduced into the terpyridine molecule to realize the locally excited state luminescence of the terpyridine molecule. It was found that the polarity of the solvent induced a change in the dipole moment of terpyridine， achieving solvent-induced fluorescence discoloration from deep blue light（λ_max=384 nm） to yellow light（λ_max=558 nm）. As the fluorescence of terpyridine is easily quenched by the oscillation of —OH group in alcohol solvent， the n-butanol， iso-butanol， sec-butanol and tert-butanol solvents with different steric hindrances make the light color of terpyridine close， while the luminous intensity difference is greater. The terpyridine is further coordinated with ZnCl₂ to obtain the terpyridine-Zn（Ⅱ） complex. The coordination of the metal ion Zn（Ⅱ） promotes the charge transfer within the terpyridine molecule. Since the N，N-dimethyl functional group， as the electron donor can undergo plane distortion， the butanol isomers can adjust the locally excited and twisted intramolecular charge transfer of terpyridine-Zn（Ⅱ）， and then realize the adjustment of its light color in butanol isomer solvent. Terpyridine and terpyridine-Zn（Ⅱ） have good solvent-induced fluorescence discoloration properties， and can be used to identify four butanol isomers.