Chirality is one of the most fundamental issues of Nature and plays a profound role in many natural and various artificial systems making it of paramount importance not only for fundamental science but also for different practical applications including pharmaceuticals, agriculture, fragrances, cosmetics, food and bio additives, catalysis, functional materials, nonlinear optics, etc. Therefore, the process of chirality sensing is of prime interest of modern research endeavors. Amongst the known methods, circular dichroism (CD) spectroscopy using porphyrin chromophores as chiroptical probes to detect chirality of various optically active compounds is the most challenging and prospective approach. Porphyrin based supramolecular chirogenic structures so far attracted much attention for chirality-sensing purposes, owing to their appropriate chemical, physico-chemical, and spectral properties, easy handling and versatile modification, direct relation to many biological processes, and wide applicability. This prompted us to apply porphyrin-based supramolecular systems for designing and development of smart chirality sensors. 

Several years ago, we have discovered that a simple ethane-bridged bis-porphyrin and bis-chlorin structural motifs can be effectively served for different application purposes owing to the specific molecular and supramolecular functionalities. In particular, the unique functional property of this bis-porphyrin host is based upon the structural semi-flexibility of covalent linkage between two porphyrin units resulting in the environmentally assisted syn-anti conformational switching and tweezer formation depending upon the guest structure, which can be effectively detected by CD and other spectroscopic methods and employed in different sensing areas, such as chirogenic probes, chiral recognitions, and chemical sensors.  

Further developments and prospects toward new chiral and achiral bis- and multi porphyrin systems on the basis of heterometallic bis- and multi-porphyrin structures will be also discussed.