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The first examples of Wolf Type II Zn2Ln-containing metallopolymers poly{MMA- co-[Zn2( L)2(4-vp)2Ln(NO3)3]} (Ln = La, Nd, Yb, Er, Gd; H2 L = N, N′-bis(salicylidene)ethylene-1,2-diamine; 4-vp = 4-vinylpyridine; MMA = methyl methacrylate) are obtained from the controlled copolymerization of heterotrinuclear Zn2Ln-arrayed complexes [Zn2( L)2(4-vp)2Ln(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-[Zn2( L)2(4-vp)2Ln(NO3)3]} (Ln = Nd, Yb, Er) hybrid materials is retained with somewhat higher intrinsic quantum yields than those of the respective Zn2Ln-arrayed complex. Especially for poly(MMA- co- 3), which has more efficient sensitization from both ligand-centered singlet (1LC) and triplet (3LC) states of the chromophores, the concentration self-quenching of Yb3+-based NIR luminescence could be effectively prevented. [ABSTRACT FROM AUTHOR]

From the self-assembly of the typical Salen-type Schiff-base ligand H L and Zn(OAc)·2HO in the molar ratio of 1:1 or 1:2, the mononuclear [Zn(L)(HO)] ( 1) or binuclear [Zn(L)(OAc)(HO)] ( 2) are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers (Zn ions) permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly(ester- co-ether)s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-(dimethylamino)pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers. [ABSTRACT FROM AUTHOR]

Abstract: With the hetero-binuclear Zn–Nd complex from the ethylene- or phenylene-linkered Salen-type Schiff-base ligand as the building block, further self-assembly of the unsymmetrical exo-dentate IN− (IN− =isonicotinic) anion gave a 2D layer polymeric [ZnL1Nd(IN)(NO3)2] n (1) (H2L1 = N,N′-bis(3-methoxy-salicylidene)ethylene-1,2-diamine) or a discrete binuclear [ZnL2Nd(IN)(NO3)2(DMF] (2) (H2L2 =N,N′-bis(3-methoxy-salicylidene)phenylene-1,2-diamine) complex, respectively. The change of linker flexibility of two Salen-type Schiff-base ligands (H2L1 and H2L2 ) resulted in the difference of structures and NIR luminescent properties of their mixed-ligands complexes. [Copyright &y& Elsevier]

Abstract: Two new near-infrared (NIR) luminescent Zn–Nd complexes [ZnL1Nd(OAc)(NO3)2] (3) and [ZnL2Nd(DMF)2(NO3)3] (4) have been obtained with two salen-type Schiff-base ligands H2L1 and H2L2 , (H2L1 = N,N′-bis(3-methoxysalicylidene)-(1s, 2s)-(−)1,2-dipheneylethylenediamine and H2L2 = N,N′-bis(3-methoxysalicylidene)-(s)-2,2-diamine-1,1′-binaphthyl) from the reaction of different chiral diamines with o-vanillin. The X-ray crystal structure analysis reveals that both of them crystallize in the chiral space groups with P2(1), a =10.1669(6), b =19.3775(11), c =17.4639(10)Å, β =94.8710(10)°, V =3428.1(3)Å3, Z =4 for 3, and C2, a =22.1914(13), b =9.7886(6), c =22.0138(13)Å, β =118.9590(10)°, V =4372.5(4)Å3, Z =4 for 4. Complexes 3–4 are both dinuclear Zn–Nd structures, while suitable choice of chiral Schiff-base ligands could induce the different complexions of ligands and metal ions, and the functional control of ligand character shows a potentially effective way to the fine-tuning properties of NIR luminescence from Nd ions. [Copyright &y& Elsevier]

Abstract: Three solvent-induced pseudo-polymorphic bimetallic Zn–Nd complexes [ZnNdL(OAc)(NO3)2(DMF)]·solvate (solvate: MeCN (1), THF (2), EtOH (3); H2L = N,N′-bis(3-methoxy-salicylidene)phenylene-1,2-diamine) were obtained, and their solid NIR luminescence related to the packing structure from the intermolecular π–π interactions was discussed. [Copyright &y& Elsevier]

Highlights: [•] Mononuclear or trinuclear Zn2+-containing catalysts based on asymmetrical bis-Schiff-base precursor. [•] Polyester or poly(ester-co-ether) polymers from CHO and MA. [•] Effect of coordination environments of metal active species on catalytic behaviors. [Copyright &y& Elsevier]

Abstract: With the Zn-Schiff-base [ZnL(CH3CN)] from the Salen-type Schiff-base ligand H2L (H2L=N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine) with the flexible linker as the precursor, a series of hetero-trinuclear Zn2Ln complexes [Zn2Ln(L)2(Cl)3] (Ln=Nd, 1; Ln=Yb, 2; Ln=Er, 3; Ln=Gd, 4) are obtained by the further reaction with LnCl3·6H2O, respectively. The results of their photophysical studies show that the strong and characteristic NIR luminescence with emissive lifetimes in the microsecond range, has been sensitized from the excited state (both 1LC and 3LC) of the ligand due to the effective intramolecular energy transfer. [Copyright &y& Elsevier]

Abstract: A monometallic (Ni2+, 1) and a series of bimetallic (Ni2+–Ln3+, Ln=Ce (2); Ln=Nd (3); Ln=Sm (4); Ln=Eu (5); Ln=Tb (6); Ln=Ho (7); Ln=Tm (8)) complexes based on the Salen-type Schiff-base ligand H 2 L (H 2 L =N,N′-bis(3-methoxysalicylidene)ethylene-1,2-diamine) were synthesized and characterized by EA, FT-IR, ESI-MS and X-ray crystallography. The catalysis results showed that the two kinds of complexes with different active species, could efficiently catalyze the bulk solvent-free melt ring-opening polymerization (ROP) of l-lactide with moderate molecular weights and narrow molecular weight distributions. Especially for the series of bimetallic complexes 2–8, the involvement of rare ions effectively passivated the catalytic behaviors on the ROP of l-lactide, while was in favor of the increase of polymeric molecular weights (M w or M n) and the polymerization controllability, and the type of rare ions was important and influential factor contributing to the catalytic behaviors. [Copyright &y& Elsevier]

Through the self-assembly of the Salen-type Schiff-base compound H 2 L ( H 2 L = N,N′-bis(3-methoxy-salicylidene)cyclohexane-1,2-diamine) with dehydrated Zn(NO 3 ) 2 and Ln(NO 3 ) 3 (Ln = La, Yb or Gd), the combination of novel μ 3 -mode bridging, μ 2 -chelating and free mode of six NO 3 − anions induces the formation of three complexes {[Zn 2 (L) 2 Ln 2 (( μ 3 -NO 3 ) 2 ( μ 2 -NO 3 ) 2 ]⋅ 2(NO 3 )} (Ln = La, 1 ; Ln = Yb, 2 or Ln = Gd, 3 ), respectively, where the compacted Zn 2 Yb 2 -array of complex 2 endows the good NIR luminescence ( Φ L Yb = 0.98% and η sens = 77%). [ABSTRACT FROM AUTHOR]