Unveiling the photophysical and morphological properties of an acidochromic thiophene flanked dipyrrolopyrazine-based chromophore for optoelectronic application

Abstract

A series of dipyrrolopyrazine (DPP) based chromophores featuring thiophene and varied donor (N,Ndimethylamine, NH 2 , OMe) and acceptor (CF 3 , CN, NO 2 ) appendages have been synthesized. The structures and properties of the chromophores were investigated by absorption spectroscopy, electrochemistry, differential scanning calorimetry, and thermogravimetric analysis. X-ray crystallographic analysis indicates a planar geometry for the molecule 7g. Surface morphological studies reveal the formation of microrods and nanorods. The acidochromic behavior of the chromophore which shows a prominent red-shift in the absorption spectra owing to the protonation of the pyrazine segment provides a valuable opportunity to assess the sensory response. Acid dependent spectral changes could be successfully applied to detect pH in biological fluids and acid impurities in solvents.

Efficient Synthesis of Dipyrrolobenzenes and Dipyrrolopyrazines via Bidirectional Gold Catalysis: a Combined Synthetic and Photophysical Study

“…The employed synthesis strategy consists of an eight-step sequence with partly difficult workup procedures, resulting in low overall yields. However, initial studies of DPPs as donor–acceptor–donor molecules, self-assembled organic micro- and nano-fibers or dye-sensitized solar cells (DSSCs) showed their potential uses in optoelectronical devices. − We therefore decided to extend the scope of our methodology to para -dipyrrolopyrazines ( p DPP ). Due to lack of accessibility of a halogenated diaminopyrazine precursor, first, we focused on Buchwald–Hartwig amination followed by Sonogashira cross-coupling of readily available 2,5-dibromo-3,6-dichloropyrazine 7 (Scheme ).…”

Design and development of a fluorometric and colorimetric sensor for toxic cyanide detection by pyridinium scaffolds: live cell imaging and real sample analysis

“…3 Most importantly, the aromatic amine group is responsible for tuning the optical properties by perturbing the D-A nature of the fluorophore. 4 The alkalinity of the pyridine ring is the binding site for various stimuli responses, such as intramolecular hydrogen bonding 5 and interaction with multiple metal cations.…”