Polyaromatic Hydrocarbon (PAH) Porphodimethene Conjugates: Conformational Features and Acid‐Anion Binding Properties

Abstract

A series of trans substituted porphodimethenes carrying varied PAH (polyaromatic hydrocarbon) substituents from phenyl to hexabenzocoronene have been synthesized. Spectroscopic and DFT (Density Functional Theory) studies clearly show that PDMs (Porphodimethenes) exhibit distortion from rooftop structure and approach planarity with increase in size of PAH units. The diacid form H2(PDM).2X− upon addition of several acids to PDMs have been characterized where X denotes Cl−, Br−, CH3SO3−, CF3COO− accompanied by an exceptional chromogenic color change from yellow to dark pink initiating with higher aromatics. The unique conformational changes with distinct color changes were monitored by UV visible, 1H NMR spectroscopy, DFT computations.