OAc^–-Dependent Self-Assembly of Luminescent Homoleptic [Ln₉(OH-Salen)₅(OH)₄(OAc)₁₀] and {[Ln₆(OH-MeO-Salen)₅(OH)(OAc)₂(H₂O)₂]·(OAc)} Complexes

Abstract

Two series of OAc–-dependent unique homoleptic nonanuclear [Ln9(L1)3(HL1)2(μ3-OH)4(OAc)10] (1–7) and hexanuclear {[Ln6(L2)4(HL2)(μ3-OH)(OAc)2(H2O)2]·(OAc)} (8–14) are obtained from the self-assembly of the partially deprotonated OH-H2Salen ligand H3L1 (N,N′-bis(salicylidene)(propylene-2-ol)-1,3-diamine) or OH-MeO-H2Salen ligand H3L2 (N,N′-bis(3-methoxysalicylidene)(propylene-2-ol)-1,3-diamine) with Ln(OAc)3 (Ln = La, Eu, Tb, Gd, Nd, Yb, or Er), respectively. The result of their photophysical properties shows that the sensitization for single-component near-white-light of complex 2, efficient Eu3+-centered red-light (ΦLEu = 13.4%) of complex 9, or or Tb3+-centered yellowish-green-light (ΦLTb = 8.1% and 21.3%) of complexes 3 and 10, and Nd3+- or Yb3+-centered NIR luminescence (η = ΦLLn/ΦLnLn = 67–75% and 76–85%) for complexes 5–6 and 12–13, arose from the ligands’ 3π–π* excited state, due to effective intramolecular energy transfer and multiple Ln3+-to-Ln3+ electron-communications.