细胞无机化学研究中需要关注的几个方面

本文评述了当前细胞无机化学研究中的几个方面,主要是包括钙离子和稀土离子在内的金属离子和活性小分子对细胞膜离子通道、膜受体蛋白、胞内受体蛋白以及对细胞功能的影响.     

Ternäre Selenide der Lanthanide mit Alkalimetallen: I. Der Formeltyp Cs3M7Se12 (M = Gd–Ho)

Ternary Selenides of the Lanthanides with Alkali Metals: I. The Composition Cs₃M₇Se₁₂ (M = Gd–Ho) When the lanthanides gadolinium, terbium, dysprosium and holmium are oxidized with selenium in a molar ratio of 2 : 3 in evacuated silica tubes (700 °C, 7 d) and CsCl is added, ternary cesium lanthanide selenides with the composition Cs₃M₇Se₁₂ (M = Gd–Ho) readily form. Surplus CsCl as flux accelerates the crystallization of the yellow, transparent needles. Since these crystals are stable to hydrolysis, excess CsCl and the chloride by-products (e. g. Cs₃MCl₆) can be rinsed off easily with water. The crystal structure of the flanking representatives Cs₃Gd₇Se₁₂ and Cs₃Ho₇Se₁₂ (orthorhombic, Pnnm (no. 58), Z = 2; Cs₃Gd₇Se₁₂: a = 1294.8(3), b = 2650.1(5), c = 419.36(9) pm, R₁ = 0.098, wR₂ = 0.173; Cs₃Ho₇Se₁₂: a = 1280.4(3), b = 2621.2(5), c = 412.13(8) pm, R₁ = 0.096, wR₂ = 0.126) was determined and refined on the basis of X-ray data from single crystals. With the help of powder diffraction Cs₃Tb₇Se₁₂ (a = 1289.4(1), b = 2640.3(2), c = 416.82(3) pm) and Cs₃Dy₇Se₁₂ (a = 1285.3(1), b = 2631.5(2), c = 414.47(3) pm) were established to be isotypic. The four new compounds crystallize isostructurally with Cs₃Y₇Se₁₂, so that a three-dimensional framework {[M₇Se₁₂]^3–} of vertex- and edge-sharing [MSe₆] octahedra is present. Wave-like, one-dimensional infinite ”︁triple-channels”︁ run through the structure along [001] which are filled with two crystallographically different Cs⁺ cations (CN(Cs1) = 7 + 1, CN(Cs2) = 6). Owing to much too close Cs⁺–Cs⁺ contacts only a semi-occupation is possible for the Cs2 position which the structure refinements inevitably prove.     

稀土掺杂无机纳米晶及其时间分辨荧光生物检测应用

时间分辨荧光生物标记作为一种灵敏的非放射性标记技术,在科研及医疗机构已获得广泛应用.传统的时间分辨荧光标记以稀土螯合物作为分子探针,存在着光化学稳定性差、长期生物毒性以及价格昂贵等缺点.稀土掺杂无机纳米晶因其优异的光化学与光物理性能,是目前普遍看好且有望成为替代稀土螯合物的新一代时间分辨纳米荧光探针.利用稀土纳米探针的...     

TbEu(BTC) as a dNTP label for LAMP outcome in nucleic acid testing

Lanthanide metal organic frameworks (MOFs), Eu(BTC) and TbEu(BTC) were assessed to follow uptake of deoxynucleotide triphosphate (dNTPs) in loop mediated isothermal amplification (LAMP) using BST2.0. dNTPs could be determined below 150 μM. A ratiometic measurement of Tb³⁺:Eu³⁺ fluorescence in TbEu(BTC) gave a limit of detection of 2.08 μM for dNTPs. dNTP uptake slowed above 8 mM Mg²⁺. This correlated with end-point and real-time LAMP, using PicoGreen and SYBR green respectively. For the P.Mal-Lau 18S rRNA primer set, with P. malariae a detection limit of 10^2.5 copies was obtained. Cross reactivity between P. malariae and P. knowlesi was shown with 18S rRNA primer sets.     

Structures and magnetic properties of two series of Schiff base binuclear lanthanide complexes

Until now, although there are many examples of studying the magnetic properties of Schiff base binuclear lanthanide complexes, the relationship between the structure and magnetic properties of the complexes still is worth further investigation in order to improve the magnetic properties of Schiff base lanthanide complexes. In this work, we successfully obtained two series of binuclear Ln complexes by in situ reaction of 4-diethylaminosalicylaldehyde, benzoic hydrazide and different lanthanide salts at 80°C under solvothermal conditions, namely, [Ln₂(L)₃(NO₃)₃]·CH₃CN·CH₃OH·H₂O [Ln = Dy ( 1 ), Ho ( 2 ), Gd ( 3 ) L = deprotonated 4-diethylamino salicylaldehyde benzoylhydrazine], [Ln₂(L)₄(CH₃COO)]CH₃COO·CH₃CN [Ln = Dy ( 4 ), Ho ( 5 ), Gd ( 6 )]. The complex 1 contains three Schiff base ligands L, two Dy (III) ions, and three NO₃⁻. The ligand H₁L is formed by in situ Schiff base reaction with 4-diethylaminosalicylaldehyde and benzoic hydrazide with the participation of Ln (NO₃)₃. When replacing Ln (NO₃)₃ with Ln (OAc)₃, obtained three μ₂-OAc bridged binuclear Ln (III) complexes. The magnetic study showed that complex 4 exhibits field-induced single-molecule magnet (SMM) behavior while complex 1 does not show any SMMs behavior. In addition, we have studied the magnetocaloric effect of complexes 3 and 6 , their maximum −ΔS_m values are 21.37 J kg⁻¹ K⁻¹ and 15.32 J kg⁻¹ K⁻¹, respectively, under ΔH = 7 T and T = 2 K.     

Identification of Favorable Silica Surface Sites for Single-Molecule Magnets

Industrial data storage application based on single-molecule magnets (SMMs) necessitates not only strong magnetic remanence at high temperatures but also requires the implementation of SMMs into a solid material to increase their durability and addressability. While the understanding of the relationship between the local structure of the metal and the resulting magnetic behavior is well understood in molecular systems, it remains challenging to establish a similar understanding for magnetic materials, especially for isolated lanthanide sites on surfaces. For instance, dispersed Dy(III) ions on silica prepared via surface organometallic chemistry exhibit slow magnetic relaxation at low temperatures, but the origin of these properties remains unclear. In this work, we modelled ten neutral complexes with coordination numbers (CN) between three and six ([Dy(OSiF₃)₃(O(SiF₃)₂)_CN-3]) representing possible surface sites for dispersed Dy(III) ions and investigated their SMM potential via ab initio CASSCF/RASSI-SO calculations. Detailed analysis of the data shows the strong influence of the spatial position of the anionic ligands while the neutral ligands only play a minor role for the magnetic properties. In particular, a T-shape like orientation of the anionic ligands is predicted to exhibit good SMM properties making it a promising targeted coordination environment for molecular and surface-based SMMs.     

Time-resolved luminescence of terbium complexes with poly(2- and 4-vinylpyridine N-oxide)s in aqueous solution

Terbium complexes with polymer ligands of poly(2- and 4-vinylpyridine N-oxide)s (P2VPNO, P4VPNO) in aqueous solution were prepared and characterized. Multi-exponential decays of the ⁵D₄ → ⁷F₅ terbium transition at 545 nm of [P2VPNO-Tb³⁺] and [P4VPNO-Tb³⁺] complexes were measured. The non-linearity of semi-logarithmic plots of time-resolved luminescence was more pronounced in [P4VPNO-Tb³⁺] than in [P2VPNO-Tb³⁺], being reduced by addition of salts such as sodium formate or acetate. We assume that multi-exponential decays of Tb³⁺ in the complexes are caused by a back metal-to-ligand energy transfer via triplet state of N-oxide polymer ligand. By carrying out separate experiments in water and deuterium oxide, the number of coordinated water molecules in the [P4VPNO-Tb³⁺] complex was estimated as 4-5, assuming that the Tb³⁺ aqua complex contains nine water molecules.