Mononuclear Rare-Earth Metalloligands Exploiting a Divergent Ligand.

Rare-earth tris-diketonato [RE(dike)pyterpy] metalloligands can be prepared reacting at room temperature [RE(dike)dme] (dme = 1,2-dimethoxyethane; dike = tta with Htta = 2-thenoyltrifluoroacetone and RE = La, ; Y, ; Eu, ; Dy, ; or dike = hfac with Hhfac hexafluoroacetylacetone, and RE = Eu, ; Tb, ; Yb ) with 4'-(4‴-pyridil)-2,2':6',2″-terpyridine (pyterpy). The molecular structures of , , , and have been studied through single-crystal X-ray diffraction showing mononuclear neutral complexes with the rare-earth ion in coordination number nine and with a muffin-like coordination geometry. [RE(tta)pyterpy] promptly reacts with [M(tta)dme] with formation of [Mpyterpy][RE(tta)] (M = Zn, RE = Y, ; M = Co, RE = Dy, ).

Size Selectivity in Heterolanthanide Molecular Complexes with a Ditopic Ligand.

The similar reactivity of lanthanides generally leads to statistically populated polynuclear complexes, making the rational design of ordered hetero-lanthanide compounds extremely challenging. Here we report on the site selectivity in hetero-lanthanide tetranuclear complexes afforded by the relatively simple ditopic pyterpyNO ligand (4'-(4-pyridil)-2,2':6',2"-terpyridine N-oxide). The sequential room temperature reaction of RE (tta) (pyterpyNO) (where RE=Y, (1); Eu, (2), Dy, (3) Htta=2-thenoyltrifluoroacetone) with La(tta) dme (dme=dimethoxyethane) yielded Y La (tta) (pyterpyNO) (4), Dy La (tta) (pyterpyNO) (5) and Eu La (tta) (pyterpyNO) (6).

Stoichiometrically Controlled Assembly of Lanthanide Molecular Complexes of the Heteroditopic Divergent Ligand 4'-(4-Pyridyl)-2,2':6',2″-terpyridine -Oxide in Hypodentate or Bridging Coordination Modes. Structural, Magnetic, and Photoluminescence Studies.

Mononuclear rare-earth tris-β-diketonato complexes RE(tta)dme [RE = Y (), La (), Dy (), or Eu (); Htta = 2-thenoylacetone; dme = 1,2-dimethoxyethane] react cleanly at room temperature in a 1:1 molar ratio with the heteroditopic divergent ligand 4'-(4-pyridyl)-2,2':6',2″-terpyridine -oxide (pyterpyNO) to yield RE(tta)(pyterpyNO), where = 2 for RE = Y (), Dy (), or Eu () and = 3 for RE = La (). The crystal structure of revealed a dinuclear compound with two pyterpyNO's bridging through the oxygen atom in a hypodentate mode leaving the terpyridine moieties uncoordinated. Using a metal:pyterpyNO molar ratio of 2 for RE = Y (), Dy (), or Eu (), it was possible to isolate the molecular complexes RE(tta)(pyterpyNO), while using a 5:3 molar ratio, the product La(tta)(pyterpyNO) () can be obtained.