Cooperative loading of multisite receptors with lanthanide containers: an approach for organized luminescent metallopolymers

Abstract

Metal loading of multi-terdentate receptors with [Eu(pbta)3] provides the first anti-cooperative factors large enough for programming metal alternation in lanthanidopolymers at room temperature.

Thermodynamic Programming of Erbium(III) Coordination Complexes for Dual Visible/Near‐Infrared Luminescence

“…The latter behavior is paralleled by the anti‐cooperative interligand interactions Δ E L k , L k (Figure b). The regular dependence of both intrinsic affinities and interligand interactions on the molecular volumes within each series suggests the prevalence of solvation effects in controlling the thermodynamic binding properties as established previously for helicate self‐assemblies and for the metal loading of linear polymers . Pertinent Born–Haber cycles developed in Appendix 2 demonstrate that, whilst the thermodynamic stabilities of the [Er( L k ) n ] 3+ ( n =1–3) complexes in acetonitrile are globally comparable for all six ligands, the minor variations along the series observed in Figure can be rationalized by a fine balance between inductive effect and size‐dependent solvation energies.…”

A Rational Approach to Metal Loading of Organic Multi‐Site Polymers: Illusion or Reality?

“…The situation changes when unsymmet-rical b-diketonate lanthanoid containers [Ln(pbta) 3 ]a re used as guests,b ecause an unprecedented anticooperative process twice as large as the thermale nergy can be evidenced in {D2[Ln(pbta) 3 ] 2 }( blue trace in Figure 11). [31] This beneficial Þ and intersite interactions DE Ln;Ln 1À2 ¼ ÀRTlnðm Ln;Ln 1À2 Þ for the loading of ligands L3 (magenta), D1 (red), D2 (green), and D3 (blue) with [Ln(hfa) 3 (dig)] (1=R Ln CN¼9 is the inverse of nine-coordinate lanthanoid radii, CD 2 Cl 2 + 0.14 m dig, 298 K). [29] Figure 11.…”

“…a) Loading of the dimer D2 with lanthanoid containersLnX 3 and b) associatedoccupancy factors and binding isotherms built from NMR titrationso fD2 with [Eu(hfa) 3 dig] (symmetricalc ontainerX= hfa:red circles) and [Eu(pbta) 3 (dig)] (unsymmetricalc ontainerX= pbta:blue triangles for 1 HNMR and bluec rosses for 19 FNMR) in CD 2 Cl 2 + 0.14 m dig at 298 K. The dotted traces correspond to the fittedc urves computed with Equations (3) and (4) and using DG EuX3 N1 and DE EuX3;EuX3 1À2 collected in the picture. [31] Figure 12. a) Intrinsic affinity parameters f Y;P3 N N3 ;sol for the loading of ligands L3 (N = 1), D1 (N = 2) and P3 N (N = 10, 12, 20, 31) with [Y(hfa) 3 ](N is the number of available tridentate bindings ites, CD 2 Cl 2 + 0.14 m dig, 298 K). The dotted tracew as fitted with Equation(10).…”

“…11). [31] The latter beneficial effect paves the way for the programming of metal alternation along one dimension. [32] Figure 11 collected in the picture.…”

“…[32] Figure 11 collected in the picture. [31] A second surprise arose with the discovery of an exponential decrease of the intrinsic affinity 3…”