Novel azacrown ether-containing spiro[indoline-2,3′-naphthoxazines]: design, synthesis and cation-dependent photochromism
Abstract
Novel spironaphthoxazine compounds with an aza-15-crown-5 ether fragment at position 5′ or 9′ of the naphthalene ring were synthesised. Spectrokinetic measurements showed the occurrence of two competing formation processes for complexation with alkaline earth or