Colorimetric “naked eye” detection of CN⁻, F⁻, CH₃COO⁻and H₂PO₄⁻ions by highly nonplanar electron deficient perhaloporphyrins

Abstract

Highly nonplanar electron deficient perhaloporphyrins were utilized for the detection of basic anions such as CN−, F−, CH3COO−and H2PO4−viaanion induced deprotonation. These sensors can be reusable without loss of their sensing ability.

Structural Modulation of Chromic Response: Effects of Binding‐Site Blocking in a Conjugated Calix[4]pyrrole Chromophore

“…This is because, notwithstanding their chromism in acidic media (halochromism), they tend to exhibit only small hypso‐ and bathochromic shifts in their absorption maxima in different solvents, leading to only weak variation in hue . Metalloporphyrins can exhibit stronger solvatochromism due to interactions between chelated metal cations and a polar coordinating solvent . Furthermore, structural changes (e.g.…”

“…[23] Metalloporphyrins can exhibit stronger solvatochromismd ue to interactions between chelated metal cations and ap olar coordinating solvent. [24,25] Furthermore, structuralc hanges (e.g. N-confusion) [26,27] have been found to lead to significant solvatochromism, whereas the inherent synthetic flexibility of porphyrins can be used to design more complicated solvatochromic systems.…”

Switchable Optical Probes for Simultaneous Targeting of Multiple Anions

“…It has been observed that multiple anions due to similarity in their basic features and complexation abilities often interact with probe molecules in an identical fashion; producing indistinguishable optical signals (Table S2). [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] Sometimes, even different modes of interaction with anions can result in the formations of identical electronic/optical states of the probe compound. Therefore, in both cases, though the sensor molecules can interact with multiple anions simultaneously; specific identification of the interacting analytes is difficult to achieve.…”

“…Considering this fundamental difference, several groups had achieved simultaneous detection of multiple anions merely varying the polarity of the host medium. Some of the recent examples (53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63)(64) based on this strategy have been shown in Table 1. [135][136][137][138][139][140][141][142][143][144][145][146]…”

Porphyrins in troubled times: a spotlight on porphyrins and their metal complexes for explosives testing and CBRN defense

“…This is due to the unavailability of the porphyrin core (i.e., the amine and imine groups) for small molecule recognition and activation, as they are shielded by the surrounding macrocycle. While there are reports on the use of free base porphyrins for sensing of VOCs, 57 water and ethanol, 136 and gases 43,46,[137][138][139][140][141] based on optical changes resulting from alterations in the microenvironment of the porphyrin, only few cases invoke a specific tailoring of the porphyrin skeleton towards improved substrate binding, anion recognition, 142,143 pH sensing, 95,144,145 or chiral sensors. 146 Similar to sensing, catalysis requires binding of the substrate to the active center; thus, molecular engineering of the tetrapyrrole scaffold can be used to increase selectivity and sensitivity.…”