New polyaminocarboxylate macrocycles containing phenolate binding units: synthesis, luminescent and relaxometric properties of their lanthanide complexes.
The synthesis of two new polyaminocarboxylate macrocycles incorporating one or two intracyclic phenol units (H4L1and H8L2, respectively) is described. The 12-membered H4L1macrocycle leads to soluble and stable mononuclear LnIIIcomplexes of [(L1)Ln(H2O)2]-composition (Ln = Eu, Tb and Gd) in aqueous solutions. In Tris buffer (pH 7.4), the [(L1)Tb(H2O)2]-complex displays a suitable efficiency for sensitized emission (ηsens= 48%) and a high luminescence quantum yield (Φ = 22%), which is worthy of note for a bis-hydrated terbium complex. Besides, luminescence experiments show that bidentate endogenous anions (citrate, carbonate, and phosphate) do not displace the two inner-sphere water molecules of this complex. In contrast, the possible presence of LMCT states causes the europium complex to be weakly luminescent. The [(L1)Gd(H2O)2]-complex is characterized by high relaxivity (r = 7.2 s-1mM-1at 20 MHz) and a very short water residence time of the coordinated water molecules (τ = 9 ns), promising values for the realisation of macromolecular systems with high relaxivities. Thus, the Tb and Gd complexes of the H4L1macrocycle exhibit several improvements in terms of luminescent (lower excitation energy, higher brightness) and relaxometric (shorter τM) properties compared to the corresponding LnPCTA complexes, where a phenol moiety substitutes a pyridine ring. On the other hand, the 24-membered H8L2macrocycle including two phenol units in its structure leads to dinuclear complexes of [(L2)Ln2]2-composition. Its terbium complex shows a long luminescence lifetime (2 ms) and a high quantum yield (43%) in aqueous solutions, making this compound a new promising candidate for time-resolved applications.
CNRS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, UMR-5068, 118 Route de Narbonne, F-31062 Toulouse cedex 9, France. picard@chimie.ups-tlse.fr galaup@chimie.ups-tlse.fr and Université de Toulouse, UPS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
Morgane
http://orcid.org/0000-0003-4144-5789
M
Enel
CNRS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, UMR-5068, 118 Route de Narbonne, F-31062 Toulouse cedex 9, France. picard@chimie.ups-tlse.fr galaup@chimie.ups-tlse.fr and Université de Toulouse, UPS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
Nadine
N
Leygue
CNRS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, UMR-5068, 118 Route de Narbonne, F-31062 Toulouse cedex 9, France. picard@chimie.ups-tlse.fr galaup@chimie.ups-tlse.fr and Université de Toulouse, UPS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
Stéphane
S
Balayssac
NMR and Molecular Imaging Laboratory, Department of General, Organic and Biomedical Chemistry, University of Mons, 23 Place du Parc, B-7000 Mons, Belgium. luce.vanderelst@umons.ac.be and Center for Microscopy and Molecular Imaging (CMMI), Rue Adrienne Bolland, 8, B-6041 Gosselies, Belgium.
Sophie
S
Laurent
CNRS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, UMR-5068, 118 Route de Narbonne, F-31062 Toulouse cedex 9, France. picard@chimie.ups-tlse.fr galaup@chimie.ups-tlse.fr and Université de Toulouse, UPS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
Chantal
C
Galaup
NMR and Molecular Imaging Laboratory, Department of General, Organic and Biomedical Chemistry, University of Mons, 23 Place du Parc, B-7000 Mons, Belgium. luce.vanderelst@umons.ac.be and Center for Microscopy and Molecular Imaging (CMMI), Rue Adrienne Bolland, 8, B-6041 Gosselies, Belgium.
Luce
L
Vander Elst
CNRS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, UMR-5068, 118 Route de Narbonne, F-31062 Toulouse cedex 9, France. picard@chimie.ups-tlse.fr galaup@chimie.ups-tlse.fr and Université de Toulouse, UPS, Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique, SPCMIB, 118 route de Narbonne, F-31062 Toulouse cedex 9, France.
Claude
http://orcid.org/0000-0002-8770-7732
C
Picard