15-Hydroxybenzomonothia-15-crown-5 with the sulfur atom linked with the benzene ring and the derived sulfoxide: synthesis, structure, and complexation with the metal cations

Abstract

Novel 15 hydroxybenzomonothia 15 crown 5 containing the sulfur atom linked with the benzene ring and its S oxide were synthesized. The stability constants for the complexes of the obtained benzocrown ethers and a reference 15 hydroxybenzo 15 crown 5 with Na, Ca, Ag I , Cd, Hg II , and Pb II perchlorates were determined by 1 H NMR titration. In MeCN-d 3 , the benzothiacrown ether demonstrates a high selectivity towards the thio and oxothiophilic Hg 2+ (logK 1 = 7.1) and Pb 2+ ions (logK 1 = 7.4). In MeCN d 3 -D 2 O mixtures, the stabilities of the most of complexes decrease sharply due to competitive hydration of the metal cations except for the "soft" Ag + and Hg 2+ ions having low affinity for the "hard" oxygen atoms and, on the contrary, very high affinity for the "soft" S II atoms. This results in the change in selectivity of complexation: at the water content in solution of 20%, the benzothiacrown ether binds prefer ably the Hg 2+ (logK 1 = 5.0) and Ag + ions (logK 1 = 2.7). In MeCN d 3 , the benzothiacrown derived sulfoxide is a weak and non selective complexing agent towards all the metal cations under study; the reference 15 hydroxybenzo 15 crown 5 forms more stable complexes with the oxophilic sodium, calcium, and lead(II) cations. The conformational features of the benzocrown ethers and their metal complexes established by NMR spectroscopy and X ray diffraction are discussed. The found characteristics of the complexing ability of benzomonothia 15 crown 5 where the sulfur atom is in conjugation with the benzene ring reveal that the macrocyclic ligands with such a structure are promising as high selective and efficient complexing agents for the "soft" mercury(II) and silver(I) cations in acetonitrile-water mixtures.

Organic Semiconductor Based on N, S‐Containing Crown Ether Enabling Efficient and Stable Perovskite Solar Cells

“…The difference between the two molecules lies in the structure of crown ether: the crown ether ring of CDT-S contains both S and N heteroatoms, while that of CDT-N only contains N heteroatom. According to previous reports, S or N atoms in crown ether could enhance the interaction between crown ether and Pb 2 + , [26,28] which may result in more effective Pb 2 + passivating ability. Results demonstrate that CDT-S could more effectively passivate defects and meanwhile improve the crystal quality of perovskite films.…”