Two Near-infrared Emissive Lanthanide-based Metal-organic Complexes Constructed from Efficient Energy Transfer Ligand

Utilizing two polycarboxylic acids as primary ligands and 1,10-phenanthrolion as an auxiliary ligand in the existence of lanthanide nitrates, two lanthanide-based complexes formulated as [Nd4（2,6-pydc OH）6（Phen）4（H2O）2]（H2O）2（1） and [Yb2（mBDC）3（Phen）2]n（2）（2,6-H2 pydc OH = 4-hydroxypyridine-2,6-dicarboxylic acid, m-H_2BDC = isophthalic acid, Phen = 1,10-phenanthroline） have been solvothermally synthesized. They have been fully characterized by satisfactory elemental analysis, FT-IR spectra, TGA and single-crystal X-ray diffraction. Single-crystal X-ray diffraction study reveals that 1 has a zero-dimensional structure and 2 exhibits a rare cds topological net structure. Compounds 1 and 2 exhibit strong characteristic emissions of Nd（Ⅲ） and Yb（Ⅲ） ions in the near-infrared（NIR） region.

Lanthanide-based microlasers:Synthesis,structures,and biomedical applications

The large size of lasers limits their applications in confined spaces,such as in biosensing and in vivo brain tissue imaging.In this regard,micron-sized lasers have been developed.They exhibit great potential for biological detecting,remote sensing,and depth tracking due to their small sizes,sensitive properties of their spectral fingerprints,and flexible positional modulation in the microenvironment.Lanthanide-based luminescent materials that possess long excited-state lifetime,narrow emission bandwidth,and upconversion behaviors are promising as gain mediums for novel microlasers.In addition,lanthanide-based microlasers could be generated under natural ambient conditions with pumped or continuous light sources,which significantly promotes the practical applications of microlasers.Recent progress in the design,synthesis,and biomedical applications of lanthanide-based microlasers has been outlined in this review.Lanthanide ions doped and upconverted lanthanide-based microlasers are highlighted,which exhibit advantageous structures,miniaturized dimensions,and high lasing performance.The applications of lanthanide-based microlasers are further discussed,the upconverted microlasers show great advantages for biological applications owing to their tunable excitation and emission characteristics and excellent environmental stability.Moreover,perspectives and challenges in the field of lanthanide-based microlasers are presented.

Plasmon-assisted mode selection lasing in a lanthanide-based microcavity

Lanthanide-based microlasers have attracted considerable attention owing to their large anti-Stokes shifts,multiple emission bands,and narrow linewidths.Various applications of microlasers,such as optical communication,optical storage,and polarization imaging,require selecting the appropriate laser polarization mode and remote control of the laser properties.Here,we propose a unique plasmon-assisted method for the mode selection and remote control of microlasing using a lanthanide-based microcavity coupled with surface plasmon polaritons(SPPs)that propagate on a silver microplate.With this method,the transverse electrical(TE)mode of microlasers can be easily separated from the transverse magnetic(TM)mode.Because the SPPs excited on the silver microplate only support TM mode propagation,the reserved TE mode is resonance-enhanced in the microcavity and amplified by the local electromagnetic field.Meanwhile,lasingmode splitting can be observed under the near-field excitation of SPPs due to the coherent coupling between the microcavity and mirror microcavity modes.Benefiting from the long-distance propagation characteristics of tens of micrometers of SPPs on a silver microplate,remote excitation and control of upconversion microlasing can also be realized.These plasmon-assisted polarization mode-optional and remote-controllable upconversion microlasers have promising prospects in on-chip optoelectronic devices,encrypted optical information transmission,and high-precision sensors.

Syntheses, Structures and Luminescent Properties of Two Europium-based Metal-organic Frameworks

Two new europium-based metal-organic-frameworks （MOFs）, namely [NMen][Eu（m- BDC）2] （1） and [Eu3（p-BDC）4（ClO4）（H2O）4] （2）, have been synthesized and structurally characte- rized. Single-crystal X-ray diffraction studies reveal that 1 crystallizes in the monoclinic system, space group P21/n with a 2D layer structure, while 2 crystallizes in the orthorhombic system, space group Pccn with a 3D net structure. Both 1 and 2 have strong characteristic Eu（Ⅲ） emissions at visible red region and the quantum yields can reach up to 78.1 and 46.0%, respectively. The high luminescent efficiency may be attributed to the efficient energy transition from the ligands to the Eu（Ⅲ） center.

Application of three Ln(Ⅲ)-coordination polymers in fields of luminescence,antibacteria and detection of Fe^(3+) and 4-nitrophenol

Three lanthanide-based coordination polymers(Ln-CPs) with layered structure,{[La_(2)(L)_(3)(DMF)(H_(2)O)_(3)]·H_(2)O}_n(1),{[Eu_(2)(L)_(3)(DMF)_(2)(H_(2)O)]·(H_(2)O)}_n(2){Tb_(2)(L)_(3)(DMF)_(2)(H_(2)O)]·H_(2)O}n(3) were successfully synthesized from H_(2)L(N,N'-bis(4-carbozylbenzyl)aniline).Remarkably,compound 3 has extremely high sensitivity to 4-nitrophenol.When the concentration of 4-nitrophenol reaches 5.98 × 10^(-3) mmol/L,the fluorescence intensity of compound 3 is quenched by 59%.The calculated K_(SV) is 7.56 × 10~4 and limit of detection(LOD) is 4.73 μg/L.3 exhibits a highly sensitive detection towards Fe^(3+) and compound 2 shows outstanding antibacterial effects on Staphylococcus aureus,re spectively.The white light emission was also investigated by changing the mixing ratio of LaNO_(3),EuNO_(3) and TbNO_(3) during the preparation of coordination polymers.

A water-stable lanthanide-coordination polymer with free Lewis site for fluorescent sensing of Fe^(3+)

A new fluorescent coordination polymer(NKU-115) was constructed under solvothermal condition based on Tb^(3+)ion and H_2L(5-(4 H-1,2,4-triazol-4-yl) benzene-1,3-dicarboxylic acid) ligand, featuring high solvent and water stability. Luminescent investigations revealed that NKU-115 shows fluorescence quenching response toward Fe^(3+)in aqueous solution and the mechanism of quenching was analyzed.