Azido-Functionalized Aromatic Phosphonate Esters in ^RPOSS-Cage-Supported Lanthanide Ion (Ln = La, Nd, Dy, Er) Coordination

Within this work, a modified preparation of diethyl 4-azidobenzylphosphonate (L1) is presented and the family 4- or 4′-azido-substituted aromatic phosphonate esters increased by three new ligand platforms: diisopropyl (L2), ((4′-azido-[1,1′-biphenyl]-4-yl)methyl)phosphonate (L3), 4-azido-2,3,5,6-tetrafluorobenzylphosphonate (L4), which exhibit an anomalous splitting N3 stretching vibrations. Subsequent coordination to in situ generated RPOSS (polyhedral oligomeric silsesquioxane)-cage-supported lanthanide precursors [(Ln{RPOSS})2(THF)m] (P1–P6) (Ln = La, Nd, Dy, Er; R iBu, Ph; m 0, 1) yields complexes general formula [Ln{RPOSS}(L1–L4)n(S1)x(THF)m] (1–30) (n 2, 3; x 1; 0–2) retaining azide unit for future semiconductor surface immobilization. Because latter compounds are mostly oils viscous waxes, preliminary solution-state structure elucidations via DOSY-ECC-MW estimations have been carried out accordance with 1H NMR integral ratios as well solid-state structures, where available. Moreover, optical properties Er derivatives 1–30 examined visible NIR spectral regions, applicable.