title: Photoaktivierungsfähige Rhodamine als Bio-Calcium-Sensoren und Markierungen für Tetracystein-Tags in Proteinen
abstract: New xanthenes with differently located azacrown ether residues were conceived and synthesized, and their spectral as well as calcium-binding properties evaluated. Three derivatives with an azacrown ether ring fused with a rhodol fluorophore were prepared (one with a secondary amino group and the other two with tertiary amino groups additionally bearing an ethyl group and an acetic acid residue). Also one derivative with the azacrown ether ring connected to the fluorophore was prepared. It was fo