Arbuzov Institute of Organic and Physical Chemistry, FRC Kazan Scientific Center, Russian Academy of Sciences, Arbuzov str. 8, 420088 Kazan, Russia.
Butlerov Institute of Chemistry, Kazan Federal University, Kremlevskaya str. 18, 420008 Kazan, Russia.
Int J Mol Sci. 2020 Sep 21;21(18):6916. doi: 10.3390/ijms21186916.
Achieving high thermal stability and control of supramolecular organization of functional dyes in sensors and nonlinear optics remains a demanding task. This study was aimed at the evaluation of thermal behavior and Langmuir monolayer characteristics of topologically varied nitrothiacalixarene multichromophores and phenol monomers. A nitration/azo coupling alkylation synthetic route towards partially O-substituted nitrothiacalixarenes and 4-nitrophenylazo-thiacalixarenes was proposed and realized. Nuclear magnetic resonance (NMR) spectroscopy and X-ray diffractometry of disubstituted nitrothiacalix[4]arene revealed a rare conformation. A synchronous thermal analysis indicated higher decomposition temperatures of nitrothiacalixarene macrocycles as compared with monomers. Through surface pressure/potential-molecular area measurements, nitrothiacalixarenes were shown to form Langmuir monolayers at the air-water interface and, through atomic force microscopy (AFM) technique, Langmuir-Blodgett (LB) films on solid substrates. Reflection-absorption spectroscopy of monolayers and electronic absorption spectroscopy of LB films of nitrothiacalixarenes recorded a red-shifted band (290 nm) with a transition from chloroform, indicative of solvatochromism. Additionally, shoulder band at 360 nm was attributed to aggregation and supported by gas-phase density functional theory (DFT) calculations and dynamic light scattering (DLS) analysis in chloroform-methanol solvent in the case of monoalkylated calixarene . Excellent thermal stability and monolayer formation of nitrothiacalixarenes suggest their potential as functional dyes.
实现功能染料在传感器和非线性光学中的高热稳定性和超分子组织控制仍然是一项具有挑战性的任务。本研究旨在评估拓扑变化的硝基硫杂杯芳烃多生色团和苯酚单体的热行为和 Langmuir 单层特性。提出并实现了一种部分 O-取代的硝基硫杂杯芳烃和 4-硝基苯偶氮硫杂杯芳烃的硝化/偶合烷基化合成路线。核磁共振（NMR）光谱和二取代硝基硫杂杯[4]芳烃的 X 射线衍射表明存在罕见的构象。同步热分析表明，与单体相比，硝基硫杂杯芳烃大环的分解温度更高。通过表面压力/电位-分子面积测量，表明硝基硫杂杯芳烃可以在空气-水界面形成 Langmuir 单层，并通过原子力显微镜（AFM）技术在固体基底上形成 Langmuir-Blodgett（LB）膜。单层的反射吸收光谱和硝基硫杂杯芳烃的 LB 膜的电子吸收光谱记录到一个红移带（290nm），从氯仿中跃迁，表明溶剂化变色。此外，在氯仿-甲醇溶剂中，对于单烷基化杯芳烃，360nm 的肩带归因于聚集，并得到气相密度泛函理论（DFT）计算和动态光散射（DLS）分析的支持。硝基硫杂杯芳烃具有优异的热稳定性和单层形成能力，表明它们有可能成为功能染料。
