In this Full Paper by Corradini et al. the legend of Figure 2 should read as follows: Portions of the ROESY 400 MHz spectra (D 2 O, pH 7.0) of a) 4, b) 3, showing cross-peaks between aromatic and aliphatic protons. A-G refer to different glucose rings. The authors apologize for this error.

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Protonation and the Cu II complexation constants of the dansylated polyamines N-dansylethylenediamine (1), N-dansyldiethylenetriamine (2), N-dansyltriethylenetetramine (3), N'-[2-(dansylamino)ethyl]diethylenetriamine (4), and tris(2-dansylaminoethyl)amine (5) were determined by glass-electrode potentiometry in MeOH/H 2 O 9 :1 (v/v) solution. For ligands 3 and 4, the determinations were also performed in aqueous solution. The complexes formed by these ligands in neutral form correspond to those observed for the analogous unsubstituted monoprotonated amines, whereas, when the ligands are deprotonated at the sulfonamide moiety, the species parallel those of the corresponding amines. The molecular structures of the complexes were deduced from the VIS absorption spectra. The crystal structure of the [CuL 2 H À2 ] complex 6 of ligand 1 (L) was determined by X-ray diffraction. The study of the photophysical properties of the ligands 3 ± 5 showed that they are good fluorescent sensors for copper(II), which induced fluorescence quenching. Time-resolved fluorescence measurements allowed us to clarify the sensing mechanism. The pH dependence of the quenching effect demonstrated that it occurs for all Cu 2 complexes, even for species in which the sulfonamide moiety is not deprotonated. Sensing of Cu 2 was compared with that of other metal ions (Co 2 , Ni 2 , Zn 2 , Cd 2 , Hg 2 ), and selectivity was studied as a function of pH. Ligands 3 and 4 were found to be selective chemosensors for Cu 2 in weakly acidic solution (pH ca. 4 ± 5).1. Introduction. ± The need of sensors for different target analytes is wellrecognized and has already stimulated considerable research devoted to the preparation of sensitive and selective sensory devices. Fluorescent chemosensors are of particular interest because of their high sensitivity and selectivity [1] in the detection of metal ions [2], anions [3], and organic bioactive molecules [4].The increasing awareness of the detrimental role that certain transition-metal ions play in human health (see, e.g., [5]) has stimulated the development of transition metal ion sensors for applications in environmental sciences, medical diagnostics, and food technology. For these reasons, many fluorescent sensors for these metal ions have been lately synthesized and characterized [1] [2] [6].In this context, we used N-dansylethylenediamine 1 ) (1) and N-dansyldiethylenetriamine 1 ) (2) ( Fig. 1; dansyl [5-(dimethylamino)naphthalen-1-yl]sulfonyl) as compo-

Sensor 1 signals the simultaneous presence of sodium and phosphate with an increased fluorescence signal in the manner of a photoionic AND logic gate.

Fluorescent monofunctionalized beta-cyclodextrins bearing a copper(II) binding side arm and a dansyl group (CD-NH-AA-CH(2)CH(2)NH-DNS) were designed as enantioselective sensors for unmodified alpha-amino acids. The side arm was derived from amino acid synthons (AA = L- and D-phenylalanine (1 and 2), L- and D-phenylglycine (3 and 4), L-proline (5), and L-cyclohexylglycine (6)) and was chosen in order to contain an amide, an amine, and a sulphonamide group. Enantioselectivity was evaluated by addition of copper(II) complexes of D- or L-valine and D- or L-proline. Chiral discrimination in the fluorescence response was observed in all cases, due to a ligand exchange process. The best conditions for these experiments were found to be the use of an excess (10:1) of the copper complex. The cyclodextrin 4 containing a D-phenylglycine unit was found to be poorly enantioselective, as found for 2, suggesting that the best design can be obtained by using L-amino acids. All L-amino acid containing cyclodextrins showed good enantioselectivities, some of which were higher than those already reported for 1. Other analytes related to amino acids were studied using cyclodextrins 1 and 3. Enantiomers of alpha,alpha-disubstituted amino acids, N-methylamino acids, and amino acid amides were found to be discriminated, while beta-phenylalanine and other molecules bearing a poor anchoring group at the alpha-carbon gave poor enantioselectivity. On the basis of the present data a model for the recognition process, based on the formation of ternary diastereomeric complexes, is proposed.

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Modified cyclodextrins bearing a metal binding site and a dansyl fluorophore 6-deoxy-6-N-(N a -[(5-dimethylamino-1-naphthalenesulfonyl)aminoethyl]-aminocylamino-b-cyclodextrin, containing L-Phe (S-1), L-PhGly (S-2) or L-Pro (S-3) moieties, were used as enantioselective fluorescence sensors for the discrimination of enantiomers of the amino acids valine and proline, according to a ligand exchange mechanism. The best conditions to perform enantiomeric analyses were studied and a fast protocol using fluorescence quenching by the copper(II)/amino acid complexes in a fluorescence microplate reader was developed, allowing the detection of samples with high enantiomeric excess. Calibration of the fluorescence response as a function of enantiomeric composition was obtained using the Stern-Volmer model; the calibration curves showed good linearity, allowing fast evaluation of enantiomeric excess within 6% error. Two calibration curves and triplicate analyses of six valine samples were performed in two minutes.

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