5-异烟酰胺异钛酸构筑的Cu(Ⅰ)-Eu和Ni(Ⅱ)-Eu化合物的合成、晶体结构和性质研究

利用不同过渡金属盐在溶剂热中合成了2个新型杂核化合物{[CuEu₂（INAIP）₃（HCOO）（H₂O）₃]·3H₂O}_n（1）和{[NiEu₂（INAIP）₄（H₂O）₄]·4H₂O}_n（2）（INAIP=异烟酰胺吡啶基异酞酸根）,并对其进行了元素分析、IR及X-射线衍射法表征。晶体结构研究表明：配合物1和2都属于三斜晶系,P1空间群。晶胞参数：配合物1a=1.0887（3）nm,b=1.5158（4）nm,c=1.5644（2）nm,V=2.3332（10）nm³,Z=2,D_c=1.955g·cm^-3,μ=3.203mm^-1,F（000）=1352,R_int=0.027,R₁=0.0505,wR₂=0.1309。配合物2a=1.0134（3）nm,b=1.0836（6）nm,c=1.3741（2）nm,V=1.4530（9）nm³,Z=1,D_c=1.878g·cm^-3,μ=2.554mm^-1,F（000）=818,R_int=0.0458,R₁=0.0341,wR₂=0.0869。配合物1是由配体异烟酰胺吡啶基异酞酸连接而成的三维二重贯穿sqc27拓扑结构,而配合物2是由配体异烟酰胺吡啶基异酞酸连接稀土铕离子形成二维层状结构,该二维层通过Ni-O和Ni-N键连接成三维非贯穿网络结构。配合物1和2具有典型的稀土铕离子红色荧光和高的热稳定性。     

肉桂酸及其衍生物的Eu(Ⅲ)配合物的合成、结构及荧光性质研究

以肉桂酸C₉H₈O₂(HL)及其衍生物对位取代肉桂酸R-L(R=CH₃,Cl,NO₂,OCH₃,OH)为配体,分别与Eu³⁺配位,得到系列Eu³⁺配合物。X-射线单晶解析结果表明:对甲基肉桂酸铕(1)和对氯肉桂酸铕(2)为一维高分子链,对硝基肉桂酸铕(3)为双核结构。通过FT-IR和UV-Vis光谱分析了配体在配位前后的变化。记录和解析了各配合物的荧光光谱,研究了对位取代基吸电子性和配位小分子对配合物发光性能的影响。     

MgF2对Mn4+掺杂锗酸盐红色荧光粉发光的影响

3.5MgO·0.5MgF₂·GeO₂∶Mn⁴⁺作为优异热稳定性和良好发光性能的红色荧光粉而被市场应用,然而,该粉体中MgF₂的作用影响机理尚不明晰,阻碍其性能进一步优化和发展。采用高温固相法制备了系列Mn⁴⁺激活的锗酸盐荧光粉,通过对比加入MgF₂、H₃BO₃(助熔剂),研究了该粉体的结构、形貌、发光性能等变化规律,阐明了MgF₂的发光影响作用。研究表明,加入MgF₂、H₃BO₃和不加任何助熔剂时的样品,其最佳烧结温度分别为1 150、1 250和1 350 ℃,上述温度下发光强度均为最佳值,其中加入MgF₂、H₃BO₃的样品在最佳温度处生成了纯相。MgF₂的添加,一方面同H₃BO₃一样作为助熔剂对生成纯相、提高样品结晶度起了积极的作用;另一方面,通过研究分析,确认F^-离子成功掺杂进入晶格,促使样品生成的晶体结构为Mg₁₄Ge₅(O,F)₂₄。加入MgF₂、H₃BO₃在最佳烧结温度的样品的荧光寿命分别为0.93和0.75 ms。     

铕配合物共掺杂电致发光器件效率滚降的延缓

将Alq₃[tris(8-hydroxyquinoline)aluminium]和Eu(TTA)₃phen(TTA=thenoyltrifluoroacetone,phen=1,10-phenanthroline)共掺杂进入主体材料CBP(4,4’-N,N’-dicarbazole-biphenyl)中,我们制作并研究了一系列电致发光器件。经过优化Alq₃的掺杂浓度,在不改变色纯度的情况下,器件的效率滚降被大幅降低并获得了近乎加倍的最大亮度。发光层中的Alq₃分子不仅促进了电子的注入和传输,还延缓了空穴的传输。借助电致发光光谱,我们证实Alq₃分子作为阶梯加速空穴从CBP分子到Eu(TTA)₃phen分子的迁移,从而促进了电子和空穴在Eu(TTA)₃phen分子上的平衡。因此,我们认为器件的效率滚降受到抑制的原因有两点：一是复合区间的加宽,二是Eu(TTA)₃phen分子上空穴和电子的分布更加平衡。     

2-丙基-1H-4，5-咪唑二酸构筑的镉(Ⅱ)配位聚合物的合成、晶体结构、形貌及荧光性质

通过水热方法 ,采用H3pimda(2-propyl-1H-imidazole-4,5-dicarboxylic acid)与CdSO4.8/3H2O和Nd2O3反应,合成了1个具有一维孔道的配位聚合物[Cd(H2pimda)2]n(1),并对其结构和荧光性质进行了研究。结构分析结果表明该聚合物的晶体属于单斜晶系,P21/n空间群。4个H2pimda-配体桥联4个镉(Ⅱ)离子形成了1个方环,这些环通过镉(Ⅱ)离子与H2pimda-配体的配位作用形成了1个具有一维孔道的三维框架结构。值得关注的是配合物1的晶体呈现一种微米管的外型。研究表明,该聚合物中在室温下能发出很强的兰色荧光。     

基于5-(4-(2,6-二(2-吡嗪基)-4-吡啶基)苯氧基)间苯二甲酸的Mn(Ⅱ)和Ca(Ⅱ)配位聚合物的合成与晶体结构

采用对苯二甲酸为模板剂, 溶剂热法合成了2个以5-(4-(2, 6-二(2-吡嗪基)-4-吡啶基)苯氧基)间苯二甲酸(H₂L)为配体的金属-有机配位聚合物:{[MnL] ·0.5H₂O}_n (1), {[CaL(H₂O)₂]·H₂O}_n (2)。通过X-射线单晶衍射, 元素分析和红外光谱进行了结构表征。结构分析表明, 1具有(3, 3)-连接的不同手性型二维层面结构, 这些交替出现的单手性左旋型和右旋型二维平面通过配体的吡啶环与吡嗪环间π…π堆积作用构成了三维超分子结构;2是通过L^2-配体羧基桥连接相邻的Ca(Ⅱ)金属中心, 形成一条平行于b轴方向的一维链结构。研究了配位聚合物的热稳定性和2的荧光性质。     

Muscle oxygenation measurement in humans by noninvasive optical spectroscopy and Locally Weighted Regression

We have developed a method to make real-time, continuous, noninvasive measurements of muscle oxygenation (Mox) from the surface of the skin. A key development was measurement in both the visible and near infrared (NIR) regions. Measurement of both oxygenated and deoxygenated myoglobin and hemoglobin resulted in a more accurate measurement of Mox than could be achieved with measurement of only the deoxygenated components, as in traditional near-infrared spectroscopy (NIRS). Using the second derivative with respect to wavelength reduced the effects of scattering on the spectra and also made oxygenated and deoxygenated forms more distinguishable from each other. Selecting spectral bands where oxygenated and deoxygenated forms absorb filtered out noise and spectral features unrelated to Mox. NIR and visible bands were scaled relative to each other in order to correct for errors introduced by normalization. Multivariate Curve Resolution (MCR) was used to estimate Mox from spectra within each data set collected from healthy subjects. A Locally Weighted Regression (LWR) model was built from calibration set spectra and associated Mox values from 20 subjects using 2562 spectra. LWR and Partial Least Squares (PLS) allow accurate measurement of Mox despite variations in skin pigment or fat layer thickness in different subjects. The method estimated Mox in five healthy subjects with an RMSE of 5.4%.     

Stability of Water/Crude Oil Systems Correlated to the Physicochemical Properties of the Oil Phase

A characterization of 30 crude oils has been performed to determine the relative level of influence that individual parameters have over the overall stability of w/o emulsions. The crude oils have been analyzed with respect to bulk and interfacial properties and the characteristics of their w/o emulsions. The parameters include compositional properties, acidity, spectroscopic signatures in the infrared and near‐infrared region, density, viscosity, molecular weight, interfacial tension, dilational relaxation, droplet size distribution, and stability to gravitationally and electrically induced separation. As expected, a strong covariance between several physicochemical properties was found. Near‐infrared spectroscopy proved to be an effective tool for crude oil analysis. In particular, we have showed the importance of the hydrodynamic resistance to electrically‐induced separation (static) in heavy crude oil‐water emulsions. A rough estimate of the drag forces and dielectrophoretic forces seemed to capture the difference between the 30 crude oils. Given enough time, water‐in‐heavy oil emulsions could be destabilized even at very low electric field magnitude (d.c.). When droplets approach each other in an inhomogeneous electric field, strong dielectrophoretic forces disintegrate the films and result in coalescence. The relative contribution from film stability to the overall emulsion stability may therefore be very different in a gravitational field compared to that in an electrical field.     

Synthesis,Crystal Structure and Luminescent Properties of a 1D Loop-chain Coordination Polymer [Ag（3,3-pybz）（3,3-Hpybz）]n

A new coordination polymer, [Ag（3,3-pybz）（3,3-Hpybz）]n （1, 3,3-Hpybz = 3-pyri- din-3-yl-benzoic acid）, has been synthesized and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray diffraction. In complex 1, the Ag（1）ions are linked by the paired 3,3-pybz ligands to generate an infinite 1D loop chain, and further through π-π stacking interactions to form a 2D supramolecular architecture. Crystal data for 1： triclinic, space group P1, a = 10.2635（17）, b = 10.3041（12）, c = 10.8060（13） A, V= 1679.1（5）A3, α = 62.028（11）, β = 80.325（15）, γ = 78.738（14）°, Z = 2, C24H17AgN2O4, Mr = 505.27, Dc= 1.698 g/cm3, μ= 1.058 mm--, F（000） = 506, S = 1.012 and T = 293（2） K. The final R = 0.0293 and wR = 0.0667 for 3435 observed reflections with I〉 2a（/）, and R = 0.0350 and wR = 0.0688 for all data.     

Synchronous ATR infrared and NIR-spectroscopy investigation of sepiolite upon drying

A new environmental cell allowing for the independent synchronous collection of the near- and mid-infrared spectra (12,000–600 cm⁻¹) in the diffuse reflection and attenuated total reflection (ATR) modes, respectively, is reported. The cell is employed to study in real time the dehydration of the phyllosilicate mineral sepiolite, Mg₈Si₁₂O₃₀(OH)₄(OH₂)₄·wH₂O, in both its natural form and after in situ deuteration at ambient. The spectra are obtained under dynamic purging with dry N₂ and compared to those of the same material conditioned over saturated salt solutions. Sepiolite is an important industrial mineral with a modulated structure of alternating tunnels and ribbons. Its mild drying is associated with pronounced vibrational spectral changes due to the removal of surface and zeolitic H₂O and the concomitant structural relaxation of the ribbons. Detailed assignments are provided for the fundamental, combination and overtone spectrum of H₂O confined in the tunnels of sepiolite, SiOH groups on the external surface of the particles, and Mg₃OH groups in the 2:1 ribbons. The spectra are discussed in comparison to those of palygorskite (modulated phyllosilicate with narrower ribbons and tunnels), talc (trioctahedral magnesian phyllosilicate without modulation) and high-surface area silica. It is demonstrated that sepiolite exhibits three discrete states of zeolitic hydration at ambient temperature: Besides the previously known hydrated (w = 7–8) and dry (w = 0–1) states which dominate the spectra above 30% and below 3% relative humidity, respectively, a hitherto unknown intermediate (w = 4–5) is found in the 3–10% range. The new state is most conveniently identified in the near-infrared by a ν₀₂ Mg₃O-H stretching mode at 7205 cm⁻¹ (ν₀₁ = 3686 cm⁻¹, X = 83.5 cm⁻¹) and a characteristic H₂O combination band at 5271 cm⁻¹ (D₂O: 3908 cm⁻¹).