First Examples of Near-Infrared Luminescent Poly(methyl methacrylate)-Supported Metallopolymers Based on Zn2Ln-Arrayed Schiff Base Complexes

The first examples of Wolf Type II Zn(2)Ln-containing metallopolymers poly{MMA-co-[Zn-2(L)(2)(4-vp)2(L)n(NO3)(3)]} (Ln = La, Nd, Yb, Er, Gd; H2L = N,N-bis(salicylidene)ethylene-1,2-diamine; 4-vp = 4-vinylpyridine; MMA = methyl methacrylate) are obtained from the controlled copolymerization of heterotrinuclear Zn(2)Ln-arrayed complexes [Zn-2(L)(2)(4-vp)(2)Ln(NO3)(3)] (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4; Ln = Gd, 5) with MMA. The strong and characteristic near-infrared (NIR) luminescent Ln3+-centered emission for each of the PMMA-supported poly{MMA-co-[Zn-2(L)(2)(4-vp)(2)Ln(NO3)(3)]} (Ln = Nd, Yb, Er) hybrid materials is retained with somewhat higher intrinsic quantum yields than those of the respective Zn(2)Ln-arrayed complex. Especially for poly(MMA-co-3), which has more efficient sensitization from both ligand-centered singlet ((LC)-L-1) and triplet ((LC)-L-3) states of the chromophores, the concentration self-quenching of Yb3+-based NIR luminescence could be effectively prevented.