Filling Tricompartmental Ligands with GdIII and ZnII Ions: Some Structural and MRI Studies
AbstractHere we report the synthesis and characterization of a mononuclear gadolinium complex (Gd) and two heteronuclear Zn-Gd complexes (ZnGd and Zn2Gd), which contain two similar three-armed ligands that display an external compartment suitable for lanthanoid ions, and two internal compartments adequate for zinc (II) ions [H3L′ = (2-(3-formyl-2-hydroxy-5-methyl phenyl)-1,3-bis[4 -(3-formyl-2-hydroxy-5-methylphenyl)-3-azabut-3-enyl]-1,3-imidazolidine; H3L = 2-(5-bromo-2-hydroxy-3-methoxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxy-3-methoxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine]. The synthetic methods used were varied, but the use of a metalloligand, [Zn2(L)AcO], as starting material was the key factor to obtain the heterotrinuclear complex Zn2Gd. The structure of the precursor dinuclear zinc complex is mostly preserved in this complex, since it is based on a compact [Zn2Ln(L)(OH)(H2O)]3+ residue, with a µ3-OH bridge between the three metal centers, which are almost forming an isosceles triangle. The asymmetric spatial arrangement of other ancillary ligands leads to chirality, what contrasts with the totally symmetric mononuclear gadolinium complex Gd. These features were confirmed by the crystal structures of both complexes. Despite the presence of the bulky compartmental Schiff base ligand, the chiral heterotrinuclear complex forms an intricate network which is predominately expanded in two dimensions, through varied H-bonds that connect not only the ancillary ligands, but also the nitrate counterions and some solvated molecules. In addition, some preliminary magnetic resonance imaging (MRI) studies have been made to determine the relaxivities of the three gadolinium complexes, with apparently improved T1 and T2 relaxivities with increasing zinc nuclearity, since both transversal and longitudinal relaxivities appear to enhance in the sequence Gd < ZnGd < Zn2Gd. View Full-Text
- Supplementary File 1:
PDF-Document (PDF, 1005 KB)
Share & Cite This Article
Corredoira-Vázquez, J.; Fondo, M.; Sanmartín-Matalobos, J.; Taboada, P.; García-Deibe, A.M. Filling Tricompartmental Ligands with GdIII and ZnII Ions: Some Structural and MRI Studies. Crystals 2018, 8, 431.
Corredoira-Vázquez J, Fondo M, Sanmartín-Matalobos J, Taboada P, García-Deibe AM. Filling Tricompartmental Ligands with GdIII and ZnII Ions: Some Structural and MRI Studies. Crystals. 2018; 8(11):431.Chicago/Turabian Style
Corredoira-Vázquez, Julio; Fondo, Matilde; Sanmartín-Matalobos, Jesús; Taboada, Pablo; García-Deibe, Ana M. 2018. "Filling Tricompartmental Ligands with GdIII and ZnII Ions: Some Structural and MRI Studies." Crystals 8, no. 11: 431.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.