Synthesis, optical spectral studies of photoemmitive benzopyranone crown ether and its application for metal ion extraction

Abstract

<span style="color:black;mso-bidi-language:HI">Synthesi<span style="color: #151515;mso-bidi-language:HI">s <span style="color:black;mso-bidi-language: HI">of a new photoemmitive<span style="color:#151515;mso-bidi-language: HI">, <span style="color:black;mso-bidi-language:HI">benzop<span style="color:#151515;mso-bidi-language:HI">y<span style="color:black; mso-bidi-language:HI">ranone 15-crown-5 (<b>1</b>) has been reported starting from 2-formyl ben<span style="color:#151515;mso-bidi-language:HI">z<span style="color:black;mso-bidi-language:HI">o-15- crown-5 by u<span style="color:#151515;mso-bidi-language:HI">s<span style="color:black; mso-bidi-language:HI">ing a straightforward protocol. Metal ion extracti<span style="color:#151515;mso-bidi-language:HI">o<span style="color:black; mso-bidi-language:HI">n profil<span style="color:#151515;mso-bidi-language: HI">e <span style="color:black;mso-bidi-language:HI">revealed <b>1</b> to ex<span style="color:#151515;mso-bidi-language:HI">t<span style="color:black;mso-bidi-language:HI">ract K⁺ more selectivel<span style="color:#151515;mso-bidi-language:HI">y ov<span style="color:black; mso-bidi-language:HI">er N<span style="color:#151515;mso-bidi-language: HI">a^{<span style="color:black;mso-bidi-language:HI">+</span>}<span style="color:black;mso-bidi-language:HI"> and Li⁺ compared to the known benz<span style="color:#151515;mso-bidi-language:HI">o<span style="color:black;mso-bidi-language:HI">-15-crown-5. However, <span style="color:#151515;mso-bidi-language:HI">e<span style="color:black; mso-bidi-language:HI">xcept f<span style="color:#151515;mso-bidi-language: HI">o<span style="color:black;mso-bidi-language:HI">r slight enhancements (8 t<span style="color:#151515;mso-bidi-language:HI">o <span style="color:black;mso-bidi-language:HI">27<span style="color:#151515; mso-bidi-language:HI">%) <span style="color:black;mso-bidi-language: HI">in the emission inten<span style="color:#151515;mso-bidi-language: HI">s<span style="color:black;mso-bidi-language:HI">ities, no appreciable changes either in the absorption or emission spectra of 1 were noticeable in the presen<span style="color:#151515;mso-bidi-language: HI">c<span style="color:black;mso-bidi-language:HI">e of s<span style="color:#151515;mso-bidi-language:HI">e<span style="color:black; mso-bidi-language:HI">lected group <b>I</b> and <b>II </b>metal ions. The absence of significant optical perturbations <span style="color:#151515; mso-bidi-language:HI">s<span style="color:black;mso-bidi-language:HI">uggests at best <span style="color:#151515;mso-bidi-language:HI">o<span style="color:black;mso-bidi-language:HI">nly weak interaction between the metal ions and the benzopyranone chromophore<span style="color:#151515; mso-bidi-language:HI">.

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