Anion-induced near-infrared (NIR) luminescent Zn2Nd and ZnNd complexes based on the pure Salen-type Schiff-base ligand

Playing with Pearson's concept: orthogonally functionalized 1,4-diaza-1,3-butadienes leading to heterobinuclear complexes

By reacting 1,2-diketones and ortho- diphenylphosphinoyl aniline in the presence of zinc(ii) as a templating agent, cationic zinc(ii) complexes of novel phosphine oxide functionalized 1,4-diaza-1,3-butadiene ligands are acessible. Herein the zinc(ii) site is bound to all four donor atoms of the ligand. Depending on the flexibility of the 1,4-diaza-1,3-butadiene backbone, the bonds to zinc(ii) from the 1,4-diaza-1,3-butadiene donors can be broken. Reaction with oxalate cleaves the zinc(ii) coordination completely and makes accessible the free ligands possessing orthogonal (N,N: soft; O,O: hard) sets of donor sites. This allows for the specific coordination of soft and hard Lewis acids and thus for the generation of heterobimetallic complexes, here exemplarily shown for the combination of palladium(ii) (soft) and zinc(ii) (hard) centres.

A Novel 3D Salen Neodymium Framework with Near-Infrared (NIR) Properties

The reaction of N,N′-bis(3-hydroxy)ethylene-1,2-diamine (H2salen) with Nd(NO3)3·6H2O and NdCl3·6H2O yields a novel lanthanide complex, namely, Nd(salen)2(NO3)2Cl (1). X-ray crystallographic analysis revealed that H2salen effectively functions as a bridging ligand forming a kind of novel 3D structure complex which is constructed by Salen ligands and mixed lanthanide counter-ions without π–π stacking and hydrogen bond interactions. This is the first Salen-type 3D lanthanide complex to be constructed in this way. The near-infrared (NIR) properties of 1 in the solid state were also studied.

Synthesis, structure, and tunable white light emission of heteronuclear Zn2Ln2 arrays using a zinc complex as ligand

White light emission was realized by codoping Eu(iii) ion in the Dy(iii) complex for the first time.

A family of acetato-diphenoxo triply bridged dimetallic ZnIILnIII complexes: SMM behavior and luminescent properties

A new family of Zn–Ln complexes that show interesting magnetic (SIM) and luminescent properties has been synthesized and characterized.

Near-infrared (NIR) luminescent hetero-tetranuclear Zn2Ln2 (Ln = Nd, Yb or Er) complexes self-assembled from the benzimidazole-based HL and two rigid 4,4'-bipyridine ligands with different spacers

Through the self-assembly of the benzimidazole-based ligand HL (HL=2-(1H-benzo[d]imidazol-2-yl)-6-methoxyphenol) with Zn(OAc)2 · 2H2O, Ln(NO3)3·6H2O (Ln=Nd, Yb, Er or Gd) and 4,4'-bipyridine ligand (bpy, 4,4'-bipyridine or bpe, trans-bis(4-pyridyl)ethylene), two series of Zn2Ln2-arrayed complexes [Zn(2)Ln(2)(L)4(bpy)(NO3)6] (Ln=Nd, 1; Yb, 2; Er, 3 or Gd, 4) and [Zn(2)Ln(2)(L)4(bpe)(NO3)6] (Ln=Nd, 5; Yb, 6; Er, 7 or Gd, 8) were obtained, respectively. The result of their photophysical properties shows that the characteristic near-infrared (NIR) luminescence of Nd(3+), Yb(3+) or Er(3+) ion has been sensitized from the excited state (both (1)LC and (3)LC) of the mixed HL and bipyridyl ligands in both complexes 1-3 and 5-7. Moreover, the change from bpy to bpe bridging for the fine-tuning of whole molecular conjugations, attributing to the different crossings of the two benzimidazole-based L(-) ligands, has the important influence on their NIR luminescent properties.

Hetero-binuclear near-infrared (NIR) luminescent Zn-Nd complexes self-assembled from the benzimidazole-based ligands

With the compound [Zn(HL(1))(2)(Py)] (H(2)L(1)=2-(1H-benzo[d]imidazol-2-yl)-6-methoxyophenol), Py=pyridine) or [Zn(HL(2))(2)(Py)] (H(2)L(2)=2-(1H-benzo[d]imidazol-2-yl)-4-bromo-6-methoxyphenol) as the precursor, complexes [ZnLn(HL(1))(2)(Py)(NO(3))(3)] (Ln=Nd, 1; Ln=Gd, 2) or [ZnLn(HL(2))(2)(Py)(NO(3))(3)] (Ln=Nd, 3; Ln=Gd, 4) were obtained by the further reaction with Ln(NO(3))(3)·6H(2)O (Ln=Nd or Gd). The result of their photophysical properties shows that the strong and characteristic near-infrared (NIR) luminescence of Nd(3+) ions for complexes 1 and 3 with emissive lifetimes in microsecond range, has been sensitized from the excited state ((1)LC and (3)LC) of the benzimidazole-based ligands, and the involvement of heavy atoms (Br) at the ligand endows the enhanced NIR luminescent property.