Smart materials displaying changes in color and optical properties in response to acid stimuli are known as acidochromic materials. The recent progress and emerging trends in the field of smart organic materials with acidochromic properties, reported in the last seven years, are presented herein. The molecular design of acidochromic organic materials, the origin of the chromic and fluorochromic response to acid stimuli, and related mechanisms are also discussed. Materials and systems covered in the review are divided according to the presence of basic moiety undergoing reversible protonation/ deprotonation, such as pyridine, quinoline, quinoxaline, azole, amine derivatives, etc., in the molecules. Many donor-acceptor molecules displaying acidochromic behavior are cited. Alterations in visual color change and optical properties supporting acidochromism are discussed for each example. Mechanistic studies based on the theoretical calculations, single crystal X-ray diffraction analysis, and powder pattern diffraction analysis are also discussed here. The application of these acidochromic molecules as acid-base switches, sensor films, self-erasable and rewritable media, data security inks, data encryption, molecular logic gates, etc., are also reported. Thus, this review article aims at giving an insight into the design, characterization, mechanism, and applications of organic acidochromic materials, which will guide the researchers in designing and fine-tuning new acidochromic materials for desired applications.

响应于酸刺激而显示出颜色和光学性质变化的智能材料被称为酸性变色材料。本文介绍了最近七年来报道的具有酸致变色特性的智能有机材料领域的最新进展和新兴趋势。还讨论了酸性变色有机材料的分子设计，铬和荧光变色对酸刺激的响应的起源以及相关的机理。综述中涵盖的材料和系统是根据分子中存在可逆质子化/去质子化的碱性部分（例如吡啶，喹啉，喹喔啉，唑，胺衍生物等）而划分的。引用了许多显示酸性变色行为的供体-受体分子。每个示例都讨论了视觉颜色变化和支持酸致变色的光学特性的变化。本文还讨论了基于理论计算，单晶X射线衍射分析和粉末图案衍射分析的机理研究。还报道了这些酸性变色分子作为酸碱开关，传感器膜，自擦除和可擦写介质，数据安全墨水，数据加密，分子逻辑门等的应用。因此，这篇综述文章旨在深入了解有机酸性变色材料的设计，表征，机理和应用，这将指导研究人员设计和微调用于所需应用的新型酸性变色材料。本文还将讨论单晶X射线衍射分析和粉末图案衍射分析。还报道了这些酸致变色分子作为酸碱开关，传感器膜，自擦除和可擦写介质，数据安全墨水，数据加密，分子逻辑门等的应用。因此，这篇综述文章旨在深入了解有机酸性变色材料的设计，表征，机理和应用，这将指导研究人员设计和微调用于所需应用的新型酸性变色材料。本文还将讨论单晶X射线衍射分析和粉末图案衍射分析。还报道了这些酸性变色分子作为酸碱开关，传感器膜，自擦除和可擦写介质，数据安全墨水，数据加密，分子逻辑门等的应用。因此，这篇综述文章旨在深入了解有机酸性变色材料的设计，表征，机理和应用，这将指导研究人员设计和微调用于所需应用的新型酸性变色材料。等，也有报道。因此，这篇综述文章旨在深入了解有机酸性变色材料的设计，表征，机理和应用，这将指导研究人员设计和微调用于所需应用的新型酸性变色材料。等，也有报道。因此，这篇综述文章旨在深入了解有机酸性变色材料的设计，表征，机理和应用，这将指导研究人员设计和微调用于所需应用的新型酸性变色材料。