DOI: 10.1002/zaac.200700164 Exploring the Interaction of Anthracene-Containing Macrocyclic Chemosensors with Silver(I) and Cadmium(II) Ions  Photophysical and Structural Studies Abel Tamayo a,b , Elisabete Oliveira a , Berta Covelo a,c , Jaume Casabo ´ b , Lluı ´s Escriche b, *, and Carlos Lodeiro a, * a Monte de Caparica / Portugal, Universidade Nova de Lisboa, Faculdade de Cie ˆncias e Tecnologia, Departamento de Quı ´mica, REQUIMTE b Bellaterra / Spain, Universitat Auto ` noma de Barcelona, Departament de Quı ´mica c Vigo / Spain, Universidade de Vigo, Centro de Apoio Cientı ´fico e Tecnolo ´gico a ´ Investigacio ´ n, Unidade Determinacio ´ n Estructural e Proteo ´ mica Received March 31st, 2007. Dedicated to Professor Alfonso Castin ˜eiras on the Occasion of his 65 th Birthday Abstract. The four anthracene-containing macrocycles 7-(9- anthracenylmethyl)-3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca- 1(17),13,15-triene (L1), 7-(10-methyl-9-anthracenylmethyl)-3,11- dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L2), 7,7'-[9,10-anthracenediylbis(methylene)]bis-3,11-dithia-7,17-diaza- bicyclo[11.3.1]heptadeca-1(17),13,15-triene (L3), and 11,-(anthra- cen-9-ylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L4), have been explored as fluorescent chemosensors for the sensing of the Introduction During the last few years, great efforts have been made to design more effective devices for detecting d 10 transition metal ions. Among these ions, Zn II is probably the most studied due to its implication in many biological processes, since it is the second most abundant transition metal in the human body [1]. Cd II and Hg II , which are potentially car- cinogenic and mutagenic ions, have also been extensively studied due to their toxicity and environmental importance, and several compounds have been recently reported as Cd II * Dr. Lluı ´s Escriche Departament de Quı ´mica Universitat Auto ` noma de Barcelona E-08193 Bellaterra / Spain Fax: + 34 93/581-2497. e-mail address: lluis.escriche@uab.es * Dr. Carlos Lodeiro REQUIMTE, Departamento de Quı ´mica Faculdade de Cie ˆncias e Tecnologia Universidade Nova de Lisboa 2829-516 Monte de Caparica / Portugal Fax: + 351 21 2948550 e-mail address: lodeiro@dq.fct.unl.pt Supporting information for this article is available on the WWW under http://www.wiley-vch.de/home/zaac or from the author Z. Anorg. Allg. Chem. 2007, 633, 1809-1814  2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1809 d 10 metal ions Ag I and Cd II . The compositions of the formed spe- cies have been determined from absorption and fluorescence titra- tions. The binding properties of L1 were also studied in the solid state. The synthesis and crystallographic characterization of com- plex [Cd(NO 3 ) 2 (L1)] are discussed. Keywords: Silver; Cadmium; Chemosensors; Anthracene; Thia- macrocycles [2] and Hg II [3] sensors. However, less attention has been paid to selective detection of monovalent d 10 metal ions such as Ag I , in spite of their applications in coordination, organometallic and supramolecular chemistry [4]. Scheme 1 A fluorescent chemosensor is an organic compound con- taining a binding site and a fluorophore unit, covalently connected through a mechanism which permits chemical communication between them [5]. Such devices are capable of signaling the presence of trace amounts of a particular analyte, and therefore are commonly used for metal ion de- tection [6]. Up to now, we have been working on various types of fluorescent chemosensors containing polyaza [7], aza-oxa [8], and aza-thia binding sites [9]. It has been shown that these aza-thia ligands form stable complexes with soft