Tetranuclear Heterometallic {Zn2Eu2} Complexes With 1‐Naphthoate Anions: Synthesis,Structure and Photoluminescence Properties

A series of new tetranuclear heterometallic Zn^II‐Eu^III complexes have been synthesized, that is, (bpy)₂Zn₂Eu₂(naph)₁₀ ( 1 ), (bpy)₂Zn₂Eu₂(naph)₈(NO₃)₂ ( 2 ), and (phen)₂Zn₂Eu₂(naph)₈(NO₃)₂ ( 3 ), and other ones, where naph^? is the 1‐naphthoate anion, bpy=2,2′‐bipyridyl, and phen=1,10‐phenanthroline. The solid‐phase complexes consist of large supramolecular ensembles due to stacking interactions between the aromatic ligands. Photoluminescence (PL) measurements were carried out to study PL spectra, lifetimes and quantum yields (QY) of the synthesized complexes at different temperatures. The external QY for the solid phases of complexes under UV excitation was found to exceed 20 %. It has been shown that partial replacement of naphthoate ligands in the coordination environment of Eu³⁺ by NO₃^? anions influences the PL properties. To investigate the behavior of these complexes in solvent, we dissolved complex 3 in MeCN, put it on a transparent glass as a substrate, and studied the PL properties at room temperature.     

3-D frameworks assembled by lanthanide dimers with 1,4-cyclohexanedicarboxylic acid and 1,10-phenanthroline via hydrogen bonds and π–π stacking interactions

Two complexes [Ln(e,a-cis-1,4-chdc)(e,a-cis-1,4-Hchdc)(phen)(H₂O)]₂?10H₂O (Ln = Eu, 1; Tb, 2, 1,4-H₂chdc = 1,4-cyclohexanedicarboxylic acid; phen = 1,10-phenanthroline) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Both complexes are doubly e,a-cis-1,4-chdc-bridged dimers. The e,a-cis-1,4-Hchdc, phen, and water molecules bond to Ln³⁺, forming nine-coordinate complexes. 3-D supramolecular frameworks are constructed by hydrogen bonds and π–π stacking interactions. Luminescence spectra exhibit the ⁵D₀ → ⁷F _J (J = 0–4) and ⁵D₄ → ⁷F _J (J = 6–3) transitions of Eu³⁺ for 1 and Tb³⁺ ion for 2, respectively.     

New Luminescent Tetranuclear Lanthanide-Based Silsesquioxane Cage-Like Architectures

The synthesis, structure, magnetic, and luminescence properties investigations of four new cage-like lanthanide-based silsesquioxanes (Cat)₂[(PhSiO_1.5)₈(LnO_1.5)₄(O)(NO_2.5)₆(EtOH)₂(MeCN)₂] (where Cat⁺=Et₄N⁺, PPh₄P⁺ and Ln³⁺=Eu³⁺, Tb³⁺ and (Ph₄P)₄[(PhSiO_1.5)₈(TbO_1.5)₄(O)₂(NO_2.5)₈]⋅10MeCN are reported. They present an unusual prism-like topology of cage architectures and lanthanide-characteristic emission, which makes them the first luminescent cage-like lanthanide silsesquioxanes. One of the Tb³⁺-based cages presents a magnetic spin-flip transition.     

Hydroxo Bridged Dinuclear Rare Earth Complexes: Syntheses and Crystal Structures of [Ln2(phen)4(H2O)4(OH)2](NO3)4(phen)2 with Ln = Er,Lu

Reactions of phenanthroline (phen) and Er(NO₃)₃ · 5 H₂O or Lu(NO₃)₃ · H₂O in CH₃OH/H₂O yield [Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄(phen)₂ with Ln = Er ( 1 ), Lu ( 2 ). Both isostructural complex compounds crystallize in the triclinic space group P 1 (no. 2) with the cell dimensions: a = 11.257(2) Å, b = 11.467(2) Å, c = 14.069(2) Å, α = 93.93(2)°, β = 98.18(1)°, γ = 108.14(1)°, V = 1696.0(6) ų, Z = 1 for ( 1 ) and a = 11.251(1) Å, b = 11.476(1) Å, c = 14.019(1) Å, α = 93.83(1)°, β = 98.27(1)°, γ = 108.27(1)°, V = 1689.0(3) ų, Z = 1 for ( 2 ). The crystal structures consist of the hydroxo bridged dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cations, hydrogen bonded NO₃^– anions and π‐π stacking (phen)₂ dimers. The rare earth metal atoms are coordinated by four N atoms of two phen ligands and four O atoms of two H₂O molecules and two μ‐OH groups to complete tetragonal antiprisms. Via two common μ‐OH groups, two neighboring tetragonal antiprisms are condensed to a centrosymmetric dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cation. Based on π‐π stacking interactions and hydrogen bonding, the complex cations and (phen)₂ dimers form 2 D layers parallel to (1 0 1), between which the hydrogen bonded NO₃^– anions are sandwiched. The structures can be simplified into a distorted CsCl structure when {[Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄} and (phen)₂ are viewed as building units.     

Synthesis,Structures, and Luminescent Properties of Lanthanide Complexes with Triphenylphospine Oxide

Seven lanthanide complexes [Ln(OPPh₃)₃(NO₃)₃] ( 1 – 3 ) (OPPh₃ = triphenylphosphine oxide, Ln = Nd, Sm, Gd), [Dy(OPPh₃)₄(NO₃)₂](NO₃) ( 4 ), [Ln(OPPh₃)₃(NO₃)₃]₂ ( 5 – 7 ) (Ln = Pr, Eu, Gd) were synthesized by the reactions of different lanthanide salts and OPPh₃ ligand in the air. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR and fluorescence spectra. Structure analysis shows that complexes 1 – 4 are mononuclear complexes formed by OPPh₃ ligands and nitrates. The asymmetric units of complexes 5 – 7 consist of two crystallographic‐separate molecules. Complex 1 is self‐assembled to construct a 2D layer‐structure of (4,4) net topology by hydrogen bond interactions. The other complexes show a 1D chain‐like structure that was assembled by OPPh₃ ligands and nitrate ions through C–H ··· O interactions. Solid emission spectra of compounds 4 and 6 are assigned to the characteristic fluorescence of Tb³⁺ (λ_em = 480, 574 nm) and Eu³⁺ (λ_em = 552, 593, 619, 668 nm).     

Synthesis of New LnxBi2–xSe3 (Ln: Sm3+, Eu3+, Gd3+, Tb3+) Nanomaterials and Investigation of Their Optical Properties

New Ln_xBi_2–xSe₃ (Ln: Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺) based nanomaterials were synthesized by a co‐reduction method. Powder XRD patterns indicate that the Ln_xBi_2–xSe₃ crystals (Ln = Sm³⁺, Eu³⁺, x = 0.00–0.44 and Ln = Gd³⁺, Tb³⁺, x = 0.00–0.50) are isostructural with Bi₂Se₃. The cell parameter c decreases for Ln = Eu³⁺, Gd³⁺, Tb³⁺ upon increasing the dopant content (x), while a slightly increases. Changes in lattice parameters could be related to the radii of cations. SEM images show that doping of the lanthanide ions in the lattice of Bi₂Se₃ generally results in nanoflowers. For the terbium compound two kinds of morphologies (nanoflowers and nanobelts) were observed. UV/Vis absorption and emission spectroscopy reveals mainly electronic transitions of the Ln³⁺ ions. Emission spectra show intense transitions from the excited to the ground state of Ln³⁺ and energy transfer from the Bi₂Se₃ lattice. Emission spectra of europium‐doped materials, in addition to the characteristic red emission peaks of Eu³⁺, show an intense blue emission band centered at 432 nm, originating from the 4f⁶5d¹ to 4f⁷ configuration in Eu²⁺. EPR measurements confirm the existence of Eu²⁺ in the materials. Interestingly, for all samples starting at low Ln³⁺ concentration, the emission intensity rises to a maximum at a Ln³⁺ concentration of x = 0.2 and falls again steadily to a minimum at x = 0.45.     

Two Isostructural Layered Lanthanide(III) Complexes: Syntheses,Structures, Magnetic and Luminescent Properties

Two N'-(2-hydroxybenzylidene)pyridine N-oxide-carbohydrazide (H₃L)-based coordination complexes with the formula [Ln₂(DMF)₂(OAc)₂(HL)₂]_n (Ln = Dy for 1 and Eu for 2 ) were solvothermally synthesized. Crystal structures, thermal stabilities, magnetic and luminescent properties of the two complexes were fully investigated. Both complexes are isomorphic two-dimensional layers with centrosymmetric {Ln₂} subunits extended by doubly deprotonated HL^2– connectors. Complex 1 with highly anisotropic Dy^III spin exhibits slightly frequency-dependent magnetic relaxations under zero dc field with an effective energy barrier of ca. 6.84 K. Eu^III-based complex 2 displays only one weak fluorescent emission around 532 nm with the absence of characteristic emission of Eu^III ion. These results provide helpful hints of the hydrazide Schiff-functionalized organic ligands on the function modulations of the resulting Ln complexes.     

Luminescence in NaLn(SO4)2H2O: A host lattice with high-energy vibrations

The luminescence of Ce³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, and Dy³⁺ in NaLn(SO₄)₂H₂O (Ln = lanthanide) is reported. Only Ce³⁺, Gd³⁺, and Tb³⁺ show efficient emission. This is explained in terms of an energy-gap law. Energy transfer is studied in several codoped compositions. The mutual transfer between Gd³⁺ ions is the only one encountered with high probability. The several transfers are discussed and where possible their rates are calculated.     

Synthesis,Structures, and Magnetic Properties of Zigzag Tetranuclear Lanthanide Complexes

Five isostructural tetranuclear lanthanide complexes with the general formula [Ln₄(teaH₂)₂(teaH)₂(NO₃)₆] · 2CH₃OH [Ln³⁺ = Dy³⁺ ( 1 ), Tb³⁺ ( 2 ), Ho³⁺ ( 3 ), Er³⁺ ( 4 ), and Gd³⁺ ( 5 )] were successfully synthesized by the reaction of various lanthanide nitrate and triethanolamine (teaH₃) ligand. Single crystal X-ray analyses reveal the eight-coordinate Ln³⁺ centers adopt a slightly distorted triangular dodecahedron geometry and nine-coordinate Ln³⁺ ions own an approximately capped square antiprism environment in similar zigzag Ln4 core. Magnetic studies demonstrate the presence of anitferromagnetic interactions between Ln³⁺ centers without obvious SMM behavior.     

A new promising phosphor, Na3La2(BO3)3:Ln (Ln=Eu, Tb)

We present an efficient way to search a host for ultraviolet (UV) phosphor from UV nonlinear optical (NLO) materials. With the guidance, Na₃La₂(BO₃)₃ (NLBO), as a promising NLO material with a broad transparency range and high damage threshold, was adopted as a host material for the first time. The lanthanide ions (Tb³⁺ and Eu³⁺)-doped NLBO phosphors have been synthesized by solid-state reaction. Luminescent properties of the Ln-doped (Ln=Tb³⁺, Eu³⁺) sodium lanthanum borate were investigated under UV ray excitation. The emission spectrum was employed to probe the local environments of Eu³⁺ ions in NLBO crystal. For red phosphor, NLBO:Eu, the measured dominating emission peak was at 613 nm, which is attributed to ⁵D₀-⁷F₂ transition of Eu³⁺. The luminescence indicates that the local symmetry of Eu³⁺ in NLBO crystal lattice has no inversion center. Optimum Eu³⁺ concentration of NLBO:Eu³⁺ under UV excitation with 395 nm wavelength is about 30 mol%. The green phosphor, NLBO:Tb, showed bright green emission at 543 with 252 nm excited light. The measured concentration quenching curve demonstrated that the maximum concentration of Tb³⁺ in NLBO was about 20%. The luminescence mechanism of Ln-doped NLBO (Tb³⁺ and Eu³⁺) was analyzed. The relative high quenching concentration was also discussed.     

A Highly Stable Yttrium Organic Framework as a Host for Optical Thermometry and D2O Detection

The yttrium organic framework (Y_0.89Tb_0.10Eu_0.01)₆(BDC)₇(OH)₄(H₂O)₄ (BDC=benzene-1,4-dicarboxylate) is hydrothermally stable up to at least 513 K and thermally stable in air in excess of 673 K. The relative intensities of luminescence of Tb³⁺ and Eu³⁺ are governed by Tb³⁺-to-Eu³⁺ phonon-assisted energy transfer and Tb³⁺-to-ligand back transfer and are responsible for the differing temperature-dependent luminescence of the two ions. This provides a ratiometric luminescent thermometer in the 288–573 K temperature range, not previously seen for MOF materials, with a high sensitivity, 1.69±0.04 % K⁻¹ at 523 K. In aqueous conditions, loosely bound H₂O can be replaced by D₂O in the same material, which modifies decay lifetimes to yield a quantitative luminescent D₂O sensor with a useful sensitivity for practical application.     

苯并咪唑衍生配体锌-铕(或铽)异金属双核配合物的合成、结构与光学性质

合成了四个锌-铕(或铽)异金属双核配合物[ZnLnL¹(NO₃)₃Py] (Ln=Eu (1), Tb (2); HL¹=1-H-2-(2-羟基-3-甲氧基苯基)苯并咪唑; Py=吡啶)和[ZnLnL²(NO₃)₃Py] (Ln=Eu (3), Tb (4); HL²=1-H-2-(2-羟基-3-甲氧基-5-溴苯基)苯并咪唑; Py=吡啶), 其中1、2、3是单晶态, 化合物4则为多晶样品; 通过单晶X射线衍射、元素分析、傅里叶变换红外光谱和电喷雾质谱对化合物进行了表征. 化合物的紫外-可见吸收光谱、荧光激发和发射光谱表明配体的激发态能量有效传递到配合物中的镧系金属离子中, 含有铽(III)离子的配合物发射出其特征发射光谱, 而含有铕(III)离子的配合物由于其它去活方式, 没有辐射出铕(III)离子的特征发射光谱.     

Syntheses,characterization and thermal properties of the lanthanide complexes with 2-mercaptonicotinic acid and 1,10-phenanthroline

Fourteen new complexes with the general formula of Ln(Hmna)₃(phen) (H₂mna = 2-mercaptonicotinic acid and phen = 1,10-phenanthroline) were synthesized and characterized by elemental analyses, IR spectra and thermogravimetric analyses. In addition, molar specific heat capacities were determined by a microcalorimeter at 298.15 K. The IR spectra of the complexes showed that the Ln³⁺ coordinated with the oxygen atoms of H₂mna and the nitrogen atoms of phen. The complexes decomposed directly to oxides Ln₂O₃, CeO₂, Pr₆O₁₁, and Tb₄O₇ in one step. The values of molar specific heat capacities for fourteen solid complexes were plotted against the atomic numbers of lanthanide, which presented as “tripartite effect”. It suggested a certain amount of covalent character existed in the bond of Ln³⁺ and ligands, according with nephelauxetic effect of 4f electrons of rare earth ions. The article is published in the original.     

Luminescence of Salen Lanthanide Bimetallic Complexes: Dual Emission and Energy Transfer

The luminescence properties of the tetranuclear bimetallic lanthanide complexes Sm₂Eu₂ ( 1 ) and Eu₂Tb₂ ( 2 ), were compared with those of the analogous homometallic complexes [Sm₄(μ₃‐OH)₂(salen)₂(acac)₆(CH₃OH)₂] · CH₃OH ( 3 ) and [Eu₄(μ₃‐OH)₂(salen)₂(acac)₆(CH₃OH)₂] ( 4 ) [H₂salen = N, N′‐ethylenebis(salicylideneimine), Hacac = acetylacetonate]. X‐ray crystallographic analysis reveals that complexes 3 and 4 have planar tetranuclear structures. For the Eu₂Tb₂ configurational isomer, the Tb^III ion in complex 2 mainly serves as a sensitizer. The quantum yields and lifetime measurements for 2 support the premise that Ln/Ln energy transfer occurs in such lanthanide bimetallic complexes, along with the usual ligand‐to‐metal triplet energy pathways. Complexes 3 and 4 exhibit the characteristic metal‐centered emission.     

Triphenylphosphane Oxide Complexes of Lanthanide Nitrates: Polymorphs and Photophysics

A series of mer‐[Ln(NO₃)₃(Ph₃PO)₃] complexes were prepared from Ln(NO₃)₃ · xH₂O and Ph₃PO in chloroform (Ln = La, Nd, Sm, Eu, Gd, Tb, Dy, and Er). The La and Nd complexes were 0.25 CHCl₃ solvates, whereas the others were solvent‐free. The identical reaction using Yb(NO₃)₃ · xH₂O produced the unique salt trans‐[Yb(NO₃)₂(Ph₃PO)₄][Yb(NO₃)₄(Ph₃PO)] · Et₂O. All nitrate ions in all complexes are η²‐chelating. A comparison of the various [Ln(NO₃)₃(Ph₃PO)₃] structures, including those in the literature, reveals at least four common polymorphs, each of which is represented by isomorphic structures of multiple Ln ions. Luminescence of mer‐[Ln(NO₃)₃(Ph₃PO)₃] (Ln = Y, La, Nd, Sm, Eu, Gd, Tb, and Dy), trans‐[Yb(NO₃)₂(Ph₃PO)₄][Yb(NO₃)₄(Ph₃PO)] and Ph₃PO assignments are reported. Latva's empirical rule allows for the antenna effect, in which energy is transferred from the triplet state of the Ph₃PO ligand, to occur only for Tb³⁺. Excitation via Ph₃PO results in strong green luminescence for Tb³⁺ having twice the intensity as that which results from direct excitation of the f‐f transitions.     

Gamma-ray induced decomposition of double nitrates of lanthanides with univalent and divalent cations

Double nitrates of Na and K having the composition 2M^INO₃·Ln^III(NO₃)₃·2H₂O(Ln^III=Pr, Nd, Sm, Eu, Gd, Tb and Dy) and of Ni and Cu with the composition 3M^II(NO₃)₂·2Ln^III(NO₃)₃·24H₂O (Ln^III=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb and Dy) have been prepared and their -radiolytic decomposition studied up to 500 kGy. G(NO ₂ ^– ) values of K double nitrates at 230 kGy follow the order Dy³⁺>Pr³⁺=Nd³⁺=Sm³⁺>Tb³⁺>Eu³⁺> Gd³⁺·G(NO ₂ ³⁺ ) for NI double nitrates are higher than those of Cu double nitrates. Variation of G(NO ₂ ^– ) with cationic radii and the number of f electrons in lanthanide ion show a minimum at Eu. Thermal decomposition studies of double nitrates were also carried out.     

Luminescence Tuning and White‐Light Emission of Co‐doped Ln–Cd–Organic Frameworks

Four new three‐dimensional isostructural lanthanide–cadmium metal–organic frameworks (Ln–Cd MOFs), [LnCd₂(imdc)₂(Ac)(H₂O)₂]?H₂O (Ln=Pr ( 1 ), Eu ( 2 ), Gd ( 3 ), and Tb ( 4 ); H₃imdc=4,5‐imidazoledicarboxylic acid; Ac=acetate), have been synthesized under hydrothermal conditions and characterized by IR, elemental analyses, inductively coupled plasma (ICP) analysis, and X‐ray diffraction. Single‐crystal X‐ray diffraction shows that two Ln^III ions are surrounded by four Cd^II ions to form a heteronuclear building block. The blocks are further linked to form 3D Ln–Cd MOFs by the bridging imdc^3? ligand. Furthermore, the left‐ and right‐handed helices array alternatively in the lattice. Eu–Cd and Tb–Cd MOFs can emit characteristic red light with the Eu^III ion and green light with the Tb^III ion, respectively, while both Gd–Cd and Pr–Cd MOFs generate blue emission when they are excited. Different concentrations of Eu³⁺ and Tb³⁺ ions were co‐doped into Gd–Cd/Pr–Cd MOFs, and tunable luminescence from yellow to white was achieved. White‐light emission was obtained successfully by adjusting the excitation wavelength or the co‐doping ratio of the co‐doped Gd–Cd and Pr–Cd MOFs. These results show that the relative emission intensity of white light for Gd–Cd:Eu³⁺,Tb³⁺ MOFs is stronger than that of Pr–Cd:Eu³⁺,Tb³⁺ MOFs, which implies that the Gd complex is a better matrix than the Pr complex to obtain white‐light emission materials.     

Mono- and Mixed Metal Complexes of Eu3+, Gd3+, and Tb3+ with a Diketone,Bearing Pyrazole Moiety and CHF2-Group: Structure,Color Tuning,and Kinetics of Energy Transfer between Lanthanide Ions

Three novel lanthanide complexes with the ligand 4,4-difluoro-1-(1,5-dimethyl-1H-pyrazol-4-yl)butane-1,3-dione (HL), namely [LnL₃(H₂O)₂], Ln = Eu, Gd and Tb, were synthesized, and, according to single-crystal X-ray diffraction, are isostructural. The photoluminescent properties of these compounds, as well as of three series of mixed metal complexes [Eu_xTb_1-xL₃(H₂O)₂] (Eu_xTb_1-xL₃), [EuxGd_1-xL₃(H₂O)₂] (Eu_xGd_1-xL₃), and [Gd_xTb_1-xL₃(H₂O)₂] (Gd_xTb_1-xL₃), were studied. The Eu_xTb_1-xL₃ complexes exhibit the simultaneous emission of both Eu³⁺ and Tb³⁺ ions, and the luminescence color rapidly changes from green to red upon introducing even a small fraction of Eu³⁺. A detailed analysis of the luminescence decay made it possible to determine the observed radiative lifetimes of Tb³⁺ and Eu³⁺ and estimate the rate of excitation energy transfer between these ions. For this task, a simple approximation function was proposed. The values of the energy transfer rates determined independently from the luminescence decays of terbium(III) and europium(III) ions show a good correlation.     

Synthesis,Structures, and Properties of Lanthanide Complexes with Pyrimidine‐2‐carboxylic Acid

Six lanthanide complexes [Ln(pmc)₂NO₃]_n [Hpmc = pyrimidine‐2‐carboxylic acid, Ln = La ( 1 ), Pr ( 2 )], [Ln(pmc)₂(H₂O)₃]NO₃ · H₂O [Ln = Eu ( 3 ), Tb ( 4 ) Dy ( 5 ), Er ( 6 )] were synthesized by the reactions of lanthanide nitrate and pyrimidine‐2‐carboxylic acid in water at room temperature. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR, circular dichroism (CD) and fluorescence spectra. Structure analysis shows that complexes 1 and 2 are isostructural with P4₃2₁2 space group, whereas isostructural complexes 3 – 6 belong to the P2₁/c space group. In complexes 1 and 2 , the central metal atoms are coordinated by nitrates and pmc^–, which are self‐assembled to construct a 3D porous network with 6₂.6₂.6₂.6₂.6₂.6₂ (6⁶) topology. In complexes 3 – 6 , H₂O and pmc^– ligands are coordinated and the complexes exhibit a one‐dimensional zigzag chain, which is further expanded into a 3D structure by hydrogen bonding. In addition, the circular dichroism of 1 and 2 proves that the two complexes are both chiral with achiral ligand of Hpmc. Luminescent measurements of compounds 3 – 5 indicate that the characteristic fluorescence of Eu³⁺, Tb³⁺, and Dy³⁺ are observed.     

Up/downconversion luminescence rare-earth ion-doped Y2O3 1D nanocrystals

Multicolor luminescent rare-earth ion-doped Y2O3 nanocrystals(NCs) were prepared by a solvethermal method.The as-synthesized NCs yielded nanosheets,nanowires(NWs) and nanorods(NRs) with the increase of alkali(NaOH) in oleic acid system.Moreover,Y2O3 nanowires with controllable size have also been obtained.After sintering,the PL intensity of Y2O3:Ln 3+ nanocrystals increased with the changed morphology of the precursor,that is,Y(OH) 3 nanocrystals.Both downconversion(red emission for Y2O3:Eu 3+ and green emission for Y2O3:Tb 3+) and upconversion(red emission for Y2O3:Yb/Er 3+) luminescence of the as-prepared nanocrystals have been demonstrated in this work.We also found that the PL intensity of Y2O3:Ln 3+ NCs dispersed in polar solvent was stronger than that in nonpolar solvent.Their up/downconversion fluorescence and controllable morphology might promise further fundamental research and biochemistry such as nanoscale optoelectronics,nanolasers,and ultrasensitive multicolor biolables.