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Rare-earth metallic ore in Siping city had produced wastewater containing ytterbium, which has caused certain environmental pollution. In view of the low removal efficiency of ytterbium in wastewater, we developed a novel PAN microtube ultrafilter device with organic P-204 system (UF-OP). The UF-OP had organic P-204 system containing wastewater part with buffer solution acetic acid and enrichment part with nitric acid solution and organic P-204[Di(2-ethylhexyl) phosphoric acid] dissolved in gasoline. Many factors of ytterbium(III) extraction using UF-OP need to explore. The effects of hydrodynamic properties and UF system parameters on the UF-OP process for ytterbium(III) extraction were also studied. The experimental results show that the best extraction conditions of ytterbium(III) were obtained as that nitric acid concentration was 4.00 mol/L, organic P-204 concentration was 0.150 mol/L, and O/W was 0.5 in the enrichment part, and pH value was 4.80 in the wastewater part. Ionic strength of metallic ore wastewater had no obvious effect on ytterbium(III) extraction. When cinit of ytterbium(III) concentration was 1.48 × 10−4 mol/L, the extraction percentage of ytterbium(III) was up to 94.8% in 160 min. The study results would provide theoretical and technical support for the treatment of wastewater containing ytterbium in metallic ore. [ABSTRACT FROM AUTHOR]

Abstract We are reporting on the use of a low‐coordinate YbIII amide with near‐ideal planar trigonal [Yb{N(SiMe3)2}3] (1) and on a bipyramidal trigonal derivative [Yb{N(SiMe2H)2}3 ⋅ (thf)2] (2) that constitute quintessential cases to investigate luminescent and magnetic properties otherwise usually blurred on less symmetrical compounds. These compounds represent the first experimental objects that allow for the confirmation of the recent conjecture about best‐performing SMM built on the archetypal prolate lanthanide ion. We have performed a combined theoretical, luminescent, and magnetic study on these molecules. For 1, a spectacular split of the 2F7/2 ground state of 1312 cm−1 is measured by low‐temperature near‐infra‐red luminescence as well as the calculated pure wavefunction composition of the low‐lying Kramers doublets, making this complex a textbook example of a prolate SMM. These results are corroborated by comparison with 2, that exhibits as expected a 50 % decrease of the ground state splitting compared to 1. Yet, we show that these remarkable features are insufficient to promote SMM behavior, and Orbach relaxation is unlikely to occur even on such an ideal low‐coordinate SMM without control of spin‐phonon coupling.

The reaction of [Ln(btfa)3(H2O)2] (btfa− = 4,4,4-trifluoro-1-phenyl-1,3-butanedionate) with additional 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbtfa) and acridine (Acr) in ethanol allows the isolation of the mononuclear compounds HAcr[Nd(btfa)4]·EtOH, (1) and HAcr[Ln(btfa)4], Ln = Dy (2) and Yb (3); HAcr+ = acridinium cation. Magnetic measurements indicate that complexes 1–3 show field-induced single-ion magnet behavior with anisotropy energy barriers and preexponential factors of Ueff = 20.7 cm−1, τ0 = 24.5 × 10−8 s; Ueff = 40.5 cm−1, τ0 = 8.6 × 10−10 s and Ueff = 22.7 cm−1, τ0 = 8.4 × 10−8 s, for 1–3 respectively. The solid-state luminescence emission in the NIR region shows efficient energy transfer from the 4,4,4-trifluoro-1-phenyl-1,3-butanedionate ligands to the central Ln3+ ion in the case of compounds 1 and 3. [ABSTRACT FROM AUTHOR]

Three new ytterbium complexes of the general formula [YbL2Cl3] with expanded aromatic N‐donor based ligands based on 1,10‐phenanthroline (dipyrido‐[3,2‐f : 2′,3′‐h]‐quinoxaline (DPQ), 2‐methyldipyrido‐[3,2‐f : 2′,3′‐h]‐quinoxaline (MeDPQ) and 1,10‐phenanthroline (Phen)) were synthesized and characterized using different structural analysis, simultaneous thermal analysis, and photoluminescence, and UV‐Vis‐NIR spectroscopy. The compounds were obtained by the reaction of ytterbium(III) chloride hexahydrate and the corresponding aromatic N‐donor through substitution of water from the coordination sphere with the organic ligand. Photoluminescence studies revealed Yb3+‐based NIR emission of the corresponding compounds with following luminescence lifetimes [Yb(DPQ)2Cl3] (1) – 7.8(1) μs, [Yb(MeDPQ)2Cl3] (2) – 9.3(1) μs, [Yb(Phen)2Cl3] (3) – 8.7(1) μs. The resulting complexes are stable under atmospheric conditions, exhibit good thermal stability, and start to oxidize only at sufficiently high temperatures: (1) at 470 °C, (2) at 430 °C, and (3) at 395 °C. [ABSTRACT FROM AUTHOR]

The reaction of [Ln(btfa)3(H2O)2] (btfa− = 4,4,4-trifluoro-1-phenyl-1,3-butanedionate) with additional 4,4,4-trifluoro-1-phenyl-1,3-butanedione (Hbtfa) and acridine (Acr) in ethanol allows the isolation of the mononuclear compounds HAcr[Nd(btfa)4]·EtOH, (1) and HAcr[Ln(btfa)4], Ln = Dy (2) and Yb (3); HAcr+ = acridinium cation. Magnetic measurements indicate that complexes 1–3 show field-induced single-ion magnet behavior with anisotropy energy barriers and preexponential factors of Ueff = 20.7 cm−1, τ0 = 24.5 × 10−8 s; Ueff = 40.5 cm−1, τ0 = 8.6 × 10−10 s and Ueff = 22.7 cm−1, τ0 = 8.4 × 10−8 s, for 1–3 respectively. The solid-state luminescence emission in the NIR region shows efficient energy transfer from the 4,4,4-trifluoro-1-phenyl-1,3-butanedionate ligands to the central Ln3+ ion in the case of compounds 1 and 3.

New heterometallic nitrate complexes, namely [Ni(bipy)3][Yb(NO3)5]·0.58MeOH (I), [Ni(phen)3][Yb(NO3)5] (II) and [Ni(phen)3][Yb(NO3)5]·MeOH (II·MeOH), have been prepared and studied. Anions [Yb(NO3)5]2– in these complexes are the first examples of homoleptic ten-coordinatied Yb complexes. The magnetic behavior of single-phase I and II has been studied in static and dynamic modes. A field-induced slowdown of magnetic relaxation, i.e., properties of single-ion magnets (SIMs), was revealed for I and II. Thus, I and II are rare examples of 3d−4f-coordination compounds possessing a discrete structure rather than a joint metal core and demonstrating a slowdown in the relaxation of magnetization. The interplay between the properties of SIM and structural features of I and II was established (CIF CCDC files no. 2103796 (I), 2103797 (II), 2103798 (II·MeOH)). [ABSTRACT FROM AUTHOR]

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Metallopolymers based on the Yb(III) complexes with 2-methyl-5-phenyl-1-pentendione-3,5 (mphpd) and allyl-3-oxobutanoate (alacac) were obtained by radical polymerization. The copolymers with methylmethacrylate and styrene in a ratio of 5:95 are obtained. The kinetics of radical polymerization of synthesized metal polymers has been studied. The complexes were characterized by infrared, absorption, diffuse reflectance and fluorescence emission spectra. The spectroscopic studies of the synthesized compounds showed that the configuration of the chelate unit is unchanged during the polymerization. By the luminescent spectroscopy is shown that all studied compounds exhibit effective luminescence. It is established that the luminescence intensity of metalopolymers and copolymers is highest for copolymers and depends on the nature of the ligands. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [YbCl2(H2O)6]Cl, was determined at 110 K. Samples were obtained from evaporated acetonitrile solutions containing the title compound, which consists of a [YbCl2(H2O)6]+ cation and a Cl− anion. The cations in the title compound sit on a twofold axis and form O—H...Cl hydrogen bonds with the nearby Cl− anion. The coordination geometry around the metal centre forms a distorted square antiprism. The ytterbium complex is isotypic with the europium complex [Tambrornino et al. (2014). Acta Cryst. E70, i27].

Two novel calix[4]arene macrocyclic ligands functionalized with four 1,3-diketone groups at the upper and hydroxyl ( 3 ) or propyloxy-groups ( 6 ) at the lower rims were synthesized and characterized using NMR, IR spectroscopy, mass spectrometry, and elemental analysis. UV–vis spectrophotometry and ESI mass spectrometry studies indicate 1:1 complex formation of ligands 3 and 6 with Ln(III) (Ln=Tb, Yb) in alkaline DMF solutions resulted from coordination of Ln(III) with 1,3-diketonate groups. Luminescence study of Ln(III) complexes with 3 and 6 reveals significant difference in antenna effects of their deprotonated forms on both Tb(III)- and Yb(III)-centered luminescence. Comparison of ligand-centered emission for ligands 3 and 6 points to the latter as more efficient antenna for Tb(III) and Yb(III). Different conformational behavior of ligands 3 and 6 in alkaline media is assumed as a reason for the experimentally observed difference in sensitization pathways in Ln(III) complexes with 3 and 6 . [ABSTRACT FROM AUTHOR]

• In situ Dimethylammonium by mild solvothermal. • In situ solvents generation can be tuned for preferred topologies. • Single crystal XRD and DFT computation. • Larger values of HOMO-LUMO energy gap is responsible for less reactive of complex. A new ytterbium(III) complex, (DMAH 2) 3 [Yb(Pydc) 3 ].4H 2 O (1) {Pydc = Pyridine-2,6-dicarboxylate anion, DMAH 2 = Dimethylammonium} has been prepared under mild solvothermal conditions and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. The DMAH 2 molecules in 1 , generated in situ from hydrolysis of N,N -dimethylformamide are responsible to assemble 2D coordination polymer through N-H···O and O-H···O hydrogen bonding. Magnetic susceptibility measurements indicate that the complex (1) obeys the Curie Weiss law and the overall magnetic behavior is typical for the presence of weak antiferromagnetic exchange coupling interactions. Theoretical data for geometrical parameters of complex 1 agree well with the experimental data. Large HOMO-LUMO energy gap of 4.33 eV has provided kinetic stability to the complex 1. NBO analysis reflects that intramolecular charge transfer occurred between ligand and metal orbitals with the highest stabilization energy of 1024.04 kcal/mol. The negative electrostatic potential at the nitrogen and dianionic pyridine-2,6-dicarboxylate regions confirms that these are dynamic locations for Yb(III) binding. : [Display omitted] [ABSTRACT FROM AUTHOR]

Synthesis, structure and properties of two alkali-lanthanide heterometallic coordination polymers with the stoichiometric formula [M(OH)(HO)Ln(NO)] (where M is Na and Ln, Er or Yb) are reported. They crystallize in the monoclinic P2/ c space group with very similar cell parameters: a = 15.8777(19) Å, b = 13.4173(18) Å, c = 13.3515(17) Å, β = 93.585(9)º, and V = 2838.8(6) Å for Er(III) and a = 15.8756(5) Å, b = 13.3707(4) Å, c = 13.3083(4) Å, β = 93.584(2)º, and V = 2819.40(15) Å for the Yb(III) polymer. The main findings in the structures of the new compounds are their isomorphism (due to the similarity between erbium and ytterbium ionic radii) and the coexistence in both of highly aqueous coordinated [Na(OH)(HO)] and [Ln(NO)] units. The luminescence measurements in the near infrared region after excitation at different wavelengths have confirmed the deleterious effect (quenching) of OH and HO groups on the emission (intensity and lifetime) of both erbium(III) and ytterbium(III) and the very weak optical absorption of lanthanides. Magnetic measurements show a paramagnetic behavior of the lanthanide centers. Graphical Abstract: Two new isostructural alkali-lanthanide coordination polymers, [Na(OH)(HO)Er(NO)] and [Na(OH)(HO)Yb(NO)], have been synthesized and characterized by X-ray diffraction. Their photoluminescent and magnetic properties are presented.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: The new styryl substituted pyrazinoporphyrazine complex has been synthesised for the first time. The spectral properties of the ytterbium complex have been studied. The introduction of the styryl fragments in the cycle leads to bathochromatic shift of the Q-band. It can be explained by the stabilisation of LUMO. [Copyright &y& Elsevier]

The (NH)[Yb(ttha)]·5HO ( I) (Httha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (NH)[Yb(pdta)(HO)]·5HO ( II) (Hpdta = propylenediamine-N,N,N′,N′-tetraacetic acid) complexes are synthesized by heat-refluxing and acidity-adjusting methods, and their structures are determined by single crystal X-ray diffraction techniques. These two complexes are all mononuclear structures. The complex I crystallizes in ttha monoclinic crystal system with the P2/ c space group. The central Yb ion is nine-coordinated only by one the ligand, and one non-coordinate carboxyl group is left. The crystal data are as follows: a = 10.321(4) Å, b = 12.744(5) Å, c = 23.203(9) Å, β = 91.082(6)°, V = 3051(2) Å, Z = 4, D = 1.754 g/cm, μ = 3.150 mm, F(000) = 1636, R = 0.0357, and wR = 0.0672 for 6203 observed reflections with I ≥ 2σ( I). The YbNO part in the [Yb(ttha)] complex anion forms a pseudo-monocapped square antiprismatic polyhedron. The complex II is coordinated with one pdta ligand and two water molecules, which form an eight-coordinate structure, and crystallizes in the triclinic crystal system with the $P\bar 1$ space group. The YbNO part in the [Yb(pdta)(HO)] complex anion makes a pseudo-square antiprismatic polyhedron. The crystal data are as follows: a = 9.8923(9)Å, b = 10.9627(10) Å, c = 12.2618(11) Å, α = 67.284(5)°, β = 70.956(6)°, γ = 68.741(5)°, V = 1115.97(18) Å, Z = 2, D = 1.843 g/cm, μ = 4.264 mm, F(000) = 618, R = 0.0177, and wR = 0.0409 for 4036 observed reflections with I ≥ 2σ( I). [ABSTRACT FROM AUTHOR]

Abstract: The axially substituted monophthalocyanine complexes of lanthanides are not enough investigated in comparison with sandwich-type phthalocyanine complexes of lanthanides because of their much lower stability in comparison with sandwich-type complexes. In this work, the new methods of obtaining monolithic silica blocks doped with acetato substituted Yb(III) monophthalocyanine complex are reported. The spectroscopic properties of this complex were measured and the results were compared for solution, solid state and xerogels dotted with PcYb(OAc). Besides of the usually observed emission of the phthalocyanines, the emission of the Yb3+ ion in IR region after excitation in phthalocyanine band (674nm) for Yb(III) complex incorporated in silica gel was observed first time. Thus, this result confirms energy transfer in the system under study. The mechanism of energy transfer was proposed. It is worth to notice, that Yb(III) emission was not observed for complex in solution and at solid state. The IR and Raman spectra of ytterbium ion in phthalocyanine complexes are reported and discussed. [ABSTRACT FROM AUTHOR]

Abstract: The ytterbium(III) extraction kinetics by 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP) in the presence of isooctanol have been investigated using constant interfacial cell with laminar flow. The stoichiometry of the complex formation reaction between the ytterbium(III) and HEHEHP in the presence of isooctanol had been evaluated. The extraction kinetics data had been analyzed in terms of pseudo-first order constants. From the temperature dependence of rate measurement, the values of Ea, ΔH and ΔS were calculated and it was found that the extraction process was a diffusion-controlled kinetics process with an interfacial reaction. The rate-determining step was made by predictions derived from interfacial reaction models, and through the approximate solutions of the flux equation, diffusion parameters and thickness of the diffusion film have been calculated. [Copyright &y& Elsevier]

Abstract: The coordination chemistry of bisphosphonates with Yb3+ was investigated to evaluate the potential of the UV–vis based detection method using the Yb3+–pyrocatechol complexation reaction as a sensor for bisphosphonates. The complexation chemistry of Yb3+ with phosphate and ATP analogs was previously described (E. Gaidamauskas, K. Saejueng, A.A. Holder, S. Bharuah, B.A. Kashemirov, D.C. Crans, C.E. McKenna, J. Biol. Inorg. Chem. 13 (2008) 1291–1299), and we here studied the complexation chemistry of bisphosphonates in this system. The spectrophotometric assay yields direct evidence for formation of a 4:3 metal to ligand complex at neutral pH. Direct evidence for Yb3+:methylenebis(phosphonate) complexes with 1:1 and 1:2 stoichiometry was also obtained by potentiometry at acidic and basic pH. Direct evidence for complex formation was obtained using 1H NMR spectroscopy although the stoichiometry was not accessed at neutral pH. Our results suggest that the spectroscopic observation of the YbPV complex can be used to conveniently measure concentrations of bisphosphonates down to 2–3μM. [Copyright &y& Elsevier]

Abstract: A selective and fast method has been developed for the determination of phosphates by measuring the formation of ytterbium(III) phosphate through the variation of the light scattering intensity with time. The low solubility of this compound causes an efficient dispersion of the radiation at 490nm, which is measured at 980nm using the second-order grating effect. This approach minimizes potential background signals from the sample matrix. The initial rate of the system is automatically obtained in only 0.5s by stopped-flow mixing technique. The variable optimization study has been carried out using univariate and multivariate methods. The dynamic range of the calibration graph is 0.09–7.9mmolL−1 (Pearson''s correlation coefficient=0.9999) and the detection limit is 0.03mmolL−1. The precision of the method, expressed as relative standard deviation, is 2.3%. The study of the potential interference of different inorganic anions showed that arsenate is the main interferent, although it is tolerated in a molar ratio of 5.5. The method has been satisfactorily applied to the determination of soluble phosphates in tap, ground and river water using a previous preconcentration step with a Dowex 1 (1×4–400) anionic resin. A 500-fold concentration has been achieved, which has allowed to decrease the detection limit up to 60mmolL−1. The recovery range is 97.5–102.5%. The results obtained are consistent with those obtained with the standard molybdenum blue method. [Copyright &y& Elsevier]

Abstract: The transamination of anionic homoleptic amido ytterbium complex, LiYb[N(i-Pr)2]4 with aryloxo-functionalized N-heterocyclic carbene (NHC) precursor, HO-4,6-di- t Bu-C6H2-2-CH2{CH[i-Pr-NCHCHN]}Cl (H2LCl) 1 and HO-4,6-di- t Bu-C6H2-2-CH2{CH[Me-NCHCHN]}Cl (H2L′Cl) 2, and BuLi in 1:2:1 molar ratio in THF at 0°C afforded the first bisaryloxo- NHC monoamido ytterbium complexes, L2Yb [N(i-Pr)2] 3 and , respectively. The same reactions in the molar ratio of 1:1 without BuLi yields also the complex 3 and 4, not the bis-amido mono aryloxo-NHC complex {LYb[N(i-Pr)2]2} and {L′Yb[N(i-Pr)2]2}. The in situ low-temperature reaction of 2 with two equivalents of BuLi, followed by addition of one equivalent of YbCl3 in THF does not afford the expected LYbCl2, instead, [Li(DME)3][YbCl4(DME)] 5 and a dimeric imidazole-aryloxo lithium {[O-4,6-di- t Bu-C6H2-2-CH2{CH(MeNCHCHNH)}]Li(THF)}2 6 which results from the 1,2-benzyl migration in N-heterocyclic carbene, are obtained. Complexes 3, 4, 5 and 6 have been characterized by elemental analysis and X-ray crystallography, and by NMR spectroscopy for 6. [Copyright &y& Elsevier]

Abstract: Studies have been made on the kinetics of ytterbium(III) with bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272, HA) in n-heptane using a constant interfacial cell with laminar flow. The stiochiometry and the equilibrium constant of the extracted complex formation reaction between Yb3+ and Cyanex 272 are determined. The extraction rate is dependent of the stirring rate. This fact together with the E a value suggests that the mass transfer process is a mixed chemical reaction–diffusion controlled at lower temperature, whereas it is entirely diffusion controlled at higher temperature. The rate equations for the ytterbium extraction with Cyanex 272 have been obtained. The rate-determining step is also made by predictions derived from interfacial reaction models, and through the approximate solutions of the flux equation, diffusion parameters and thickness of the diffusion film have been calculated. [Copyright &y& Elsevier]

The ytterbium(III) extraction kinetics and mechanism with mixtures of bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex272) and 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (P507) dissolved in heptane have been investigated by constant interfacial cell with laminar flow. The effects of the stirring rate, temperature, extractant concentration, and pH on the extraction with mixtures of Cyanex272 and P507 have been studied. The results are compared with those of the system with Cyanex272 or P507 alone. It is concluded that the Yb(III) extraction rate is enhanced with mixtures extractant of Cyanex272 and P507 according to their values of the extraction rate constant, which is due to decreasing the activation energy of the mixtures. Atthe same time, the mixtures exhibits no synergistic effects for Y(III), which provides better possibilities for Yb(III) and Y(III) separations at a proper conditions than anyone alone. Moreover, thermodynamic extraction separation Yb(III) and Y(III) by the mixtures has been discussed, which agrees with kinetics results. Extraction rate equations have also been obtained, and through the approximate solutions of the flux equation, diffusion parameters and thickness of the diffusion film have been calculated. [ABSTRACT FROM AUTHOR]

Ytterbium(III) reagent supported on ion exchange resin is applied to the multicomponent condensation reactions under solvent-free conditions. One-pot synthesis of a library of 3,4-dihydropyrimidine-2(1H)-thiones and quinazolin-4(3H)-ones were described. The advantages of easy separation and recyclability of the catalysts were demonstrated. [ABSTRACT FROM AUTHOR]

An 1H, 13C, and 15N NMR study has been completed for the complexes of La(III), Tm(III), and Yb(III) with nitrate and isothiocyanate in aqueous solvent mixtures. Signals for four complexes are observed for both the Tm3+–NO3 − and Yb3+–NO3 − solutions, with the species identified as the mono-, di-, tetra-, and either the penta - or hexanitrato. These results are consistent with those determined for the nitrate complexes of the Ce(III)–Eu(III) metal ions. The chemical shifts for the Tm(III) and Yb(III) nitrate complexes indicate a pseudocontact binding mechanism prevails. The complexes of diamagnetic La(III) with NO3 − produce three signals in the 15NO3 − spectra, with assignments paralleling those observed with the paramagnetic lanthanides. Three complexes are formed in the La3+–NCS− solutions, with signals assigned to the mono-, di-, and triisothiocyanato species. [ABSTRACT FROM AUTHOR]

Cationic lanthanide complexes are generally able to spontaneously internalize into living cells. Following our previous works based on a diMe-cyclen framework, a second generation of cationic water-soluble lanthanide complexes based on a constrained cross-bridged cyclam macrocycle functionalized with donor-π-conjugated picolinate antennas was prepared with europium(III) and ytterbium(III). Their spectroscopic properties were thoroughly investigated in various solvents and rationalized with the help of DFT calculations. A significant improvement was observed in the case of the Eu 3+ complex, while the Yb 3+ analogue conserved photophysical properties in aqueous solvent. Two-photon (2P) microscopy imaging experiments on living T24 human cancer cells confirmed the spontaneous internalization of the probes and images with good signal-to-noise ratio were obtained in the classic NIR-to-visible configuration with the Eu 3+ luminescent bioprobe and in the NIR-to-NIR with the Yb 3+ one., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The crystal structure of the title compound, [YbCl2(H2O)6]Cl, was determined at 110 K. Samples were obtained from evaporated aceto-nitrile solutions containing the title compound, which consists of a [YbCl2(H2O)6](+) cation and a Cl(-) anion. The cations in the title compound sit on a twofold axis and form O-H⋯Cl hydrogen bonds with the nearby Cl(-) anion. The coordination geometry around the metal centre forms a distorted square anti-prism. The ytterbium complex is isotypic with the europium complex [Tambrornino et al. (2014 ▶). Acta Cryst. E70, i27].