Ce1－xNdxO2－δ固溶体的电子顺磁共振谱和阻抗谱的研究

利用溶胶-凝胶方法在800 ℃焙烧10 h后, 合成了固溶体Ce_1－xNd_xO_2－δ (x＝0.05～0.55), X射线衍射(XRD)测试表明固溶体已经形成立方萤石结构; 电子顺磁共振谱(EPR)研究表明在固溶体Ce_1－xNd_xO_2－δ中随着掺杂量x的增大, Ce^3＋离子含量减少, 说明掺杂Nd^3＋离子可以抑制Ce^4＋的还原; 交流阻抗谱的测量表明固溶体Ce_0.9Nd_0.1O_2－d 具有离子导电特性, 600和700 ℃时的电导率分别为4.25×10^－3和1.12×10^－2 S•cm^－1, 活化能为0.68 eV.     

掺杂纳米SiO2的PVDF-g-PSSA质子交换膜

以聚偏氟乙烯(PVDF)为骨架, 采用溶液接枝苯乙烯磺酸, 合成了掺杂纳米SiO₂颗粒的复合质子交换膜(PVDF/xSiO₂-g-PSSA). 利用红外光谱、热失重分析方法、扫描电镜, 对膜的结构、热稳定性、表面及断面形态进行了表征. 考察了膜的吸水率、电导率、甲醇渗透性等性质. 结果表明, 纳米SiO₂颗粒能提高膜的阻醇性能, 掺杂质量分数10%的适量SiO₂颗粒所得的复合膜的甲醇渗透系数达1.0×10^－7 cm²/s, 低于聚偏氟乙烯接枝苯乙烯磺酸(PVDF-g-PSSA)膜的1.7×10^－7 cm²/s, 仅为Nafion-117的渗透系数的二十分之一. PVDF/10% SiO₂-g-PSSA复合膜具有较高的选择性, 在直接甲醇燃料电池中具有良好的应用前景.     

反式N-3-炔丁烯基咔唑的合成及其齐聚行为

在65 ℃、氮气保护下, 往咔唑钠的四氢呋喃溶液中缓慢滴加1,4-二氯-2-丁炔. 反应9 h后, 在苯和石油醚混合溶剂中重结晶, 分离得到反式N-3-炔丁烯基咔唑. 在加热, BPO, BF₃, FeCl₃, P₂O₅, 紫外或可见光的引发作用下, 反式N-3-炔丁烯基咔唑发生齐聚反应. 通过元素分析, IR, ¹H NMR, MS, UV等方法对反应产物进行分析表征. IR和¹H NMR图谱显示单体聚合后炔基及其相连氢原子的特征吸收峰(ν: 3278, 2099 cm^－1; : 2.8～3.0)消失, VPO法测得齐聚物分子量在8.3×10²至1.9×10³之间(聚合度4～9).     

[1-芳基甲羰基-2-(1,2,4-三唑-1-基)]乙基-N,N-二烷基二硫代氨基甲酸酯衍生物的合成、结构表征及生物活性研究

以芳香基三唑类杀菌剂三唑酮为先导物设计并合成了5个含N,N-二烷基二硫代氨基甲酸酯的芳香三唑类化合物, 通过元素分析、红外光谱、核磁共振氢谱和质谱对其结构进行了表征. 用X射线单晶衍射测定了[α-(4-甲氧基苯甲酰基)-2-(1,2,4-三唑-1-基)]乙基-N,N-二甲基二硫代氨基甲酸酯的晶体结构, 晶体属于三斜晶系, 空间群, 晶胞参数为: a＝0.73482(15) nm, b＝1.1051(2) nm, c＝1.1209(2) nm, α＝90.32(3)°, β＝101.97(3)°, γ＝105.13(3)°, V＝0.8578(3) nm³, Z＝2, D_c＝1.357 g/cm³, F(000)＝368, µ＝0.324 mm^－1. 生物测试结果显示这5种有机化合物都具有杀菌性和植物生长调节活性     

Criegee自由基CH2O2与H2O反应机理及动力学的理论研究

在6-311＋G(2d,2p)水平下, 采用密度泛函理论(DFT)的B3LYP方法, 研究了Criegee 自由基CH₂O₂与H₂O的反应. 结果表明反应存在三个通道: CH₂O₂＋H₂O®HOCH₂OOH (R1); CH₂O₂＋H₂O®HCO＋OH＋H₂O (R2); CH₂O₂＋H₂O®HCHO＋H₂O₂ (R3), 各通道的势垒高度分别为43.35, 85.30和125.85 kJ/mol. 298 K下主反应通道(R1)的经典过渡态理论(TST)与变分过渡态理论(CVT)的速率常数k^TST与k^CVT均为2.47×10^－17 cm³•molecule^－1•s^－1, 而经小曲率隧道效应模型(SCT)校正后的速率常数k^CVT/SCT为 5.22×10^－17 cm³•molecule^－1•s^－1. 另外, 还给出了200～2000 K 温度范围内拟合得到的速率常数随温度变化的三参数Arrhenius方程.     

Pr掺杂对Ce5.2Sm0.8MoO15－δ晶界及电性能的影响

在Ce_5.2Sm_0.8－xPr_xMoO_15－δ体系中引入少量Pr得新氧化物Ce_5.2Sm_0.72Pr_0.08MoO_15－δ, 通过X射线衍射(XRD), 拉曼光谱(Raman), X射线光电子能谱(XPS), 场发射扫描电镜(FE-SEM)等手段对氧化物结构进行分析, 交流阻抗谱测试电性能; 讨论掺杂少量Pr对Ce_5.2Sm_0.8MoO_15－δ微观结构和电性能的影响. 结果表明, 少量Pr^3＋的掺杂可降低晶界电阻, 增加离子扩散通道, 降低体系的总电导激活能和晶界电导激活能, 提高氧化物的总电导率和晶界电导率; 500 ℃时掺Pr材料的晶界电导率为6.79×10^－3 S•cm^－1, 比未掺Pr材料的晶界电导率(5.61×10^－5 S•cm^－1)提高约2个数量级.     

手性3,5-二甲基-2-芳基-2-吗啉醇盐酸盐的合成及其晶体结构

以(S)-2-氨基丙醇为手性源与α-溴-3-氯苯丙酮反应, (R)-2-氨基丙醇为手性源与6-甲氧基-2-(2-溴丙酰基)萘反应, 分别合成了手性纯化合物(2R,3R,5S)-3,5-二甲基-2-(3-氯苯基)-2-吗啉醇盐酸盐(4a)和(2S,3S,5R)-3,5-二甲基-2-(6-甲氧基-2-萘基)-2-吗啉醇盐酸盐(4b), 利用X射线单晶衍射仪测定了两化合物的晶体结构和两化合物的空间结构, 并初步分析两化合物空间结构, 化合物4a晶体属正交晶系, 空间群为P2₁2₁2, 晶胞参数为: a＝0.8718(2) nm, b＝0.7883(2) nm, c＝2.0247(6) nm, Z＝4, V＝1.3915(7) nm³, D_c＝1.328 g/cm³, F(000)＝584, R₁＝0.0399, wR₂＝0.0797, S＝1.042. 化合物4b晶体属正交晶系, 空间群为P2₁2₁2₁, 晶胞参数为: a＝0.71035 (9) nm, b＝0.77703(10) nm, c＝2.9820(4) nm, Z＝4, V＝1.6318(4) nm³, D_c＝1.318 g/cm³, F(000)＝688, R₁＝0.0520, wR₂＝0.1108, S＝0.994.     

N,N'-二(二乙氧基硫代磷酰基)-1,4-苯二胺的合成、晶体结构及热性能研究

通过二乙氧基硫代磷酰氯与对苯二胺反应生成了标题化合物N,N'-二(二乙氧基硫代磷酰基)-1,4-苯二胺，并应用元素分析, FTIR及¹H NMR对标题化合物进行了表征. 利用X射线单晶衍射测定了其晶体结构, 同时应用TG分析法对其热性能进行了分析. 标题化合物的相对分子质量M_r＝412.42, 为正交晶系, Pbca空间群, 晶胞参数为a＝0.86936(16) nm, b＝1.2787(2) nm, c＝1.8897(3) nm, β＝90°, V＝2.1006(7) nm³, Z＝8, D_c＝1.304 g/cm³, μ(Mo Kα)＝0.425 mm^－1, F(000)＝872, S＝1.052. 最终偏离因子R＝0.0628, wR＝0.1860, 可观测衍射点1852个[I＞2σ(I)]. 该晶体通过对苯二胺连接并以中心对称分布, 并形成层状结构, 且存在弱的分子内氢键N—H…S. TG分析表明该化合物有很好的热稳定性及成炭性, 通过其阻燃聚丙烯腈表明, 该物质是一种高效能的膨胀型阻燃剂.     

(H2teta)2{[Ni(teta)][Fe(CN)6]2}•17H2O (teta＝5,7,7,12,14,14-Hexa-methyl-1,4,8,11-tetraazacyclotetradecane)超分子化合物的合成、晶体结构和磁性质研究

将Ni(teta)(ClO₄)₂ (teta＝5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)的DMF溶液和K₃[Fe(CN)₆]的水溶液在填充了琼脂冻胶的U型管中通过扩散反应, 得到了标题化合物(H₂teta)₂{[Ni(teta)][Fe(CN)₆]₂}•17H₂O, 该化合物晶体属三斜晶系, 空间群P1, 晶胞参数为a＝0.9998(2) nm, b＝1.5514(3) nm, c＝1.6647(4) nm, α＝114.15(2)°, β＝100.91(2)°, γ＝93.42(2)°, V＝2.2863(10) nm³, z＝1, D_c＝1.196 g•cm^－3, F(000)＝890, μ＝5.84 cm^－1, GOF＝0.894, R₁＝0.0582, wR₂＝0.1446 [I＞2σ(I)]. 该化合物的基本单元由2个[H₂teta]^2＋阳离子、1个{[Ni(teta)][Fe(CN)₆]₂}^4－阴离子和17个水分子组成, 它们之间通过N—H…N氢键而形成具有二维平面结构的超分子化合物. 1.8～300 K变温磁化率研究表明, 化合物中三核体系Fe (s＝1/2)-Ni (s＝1)-Fe (s＝1/2)中心原子间通过氰基桥联而发生强的铁磁相互作用, 磁参数J＝4.33 cm^－1, g＝2.6, θ＝60 K. 通过TG-DTG测定了配合物的热稳定性.     

C60-吡咯烷衍生物的合成及非线性光学性质的研究

通过富勒烯C₆₀与肌氨酸和有机醛化合物的1,3-偶极环加成反应, 获得了九种含不同有机功能基团的C₆₀吡咯烷衍生物1～9, 用¹H NMR, ¹³C NMR, FTIR, UV-vis和FAB-MS进行了结构表征; 利用皮秒激光光源, 采用z扫描技术测定了分子的三阶非线性超极化率γ⁽³⁾, 结果显示: 化合物3 (γ⁽³⁾＝4.14×10^－33 esu)具有最大的三阶非线性光学系数, 说明增加噻吩共轭链的长度, 使三阶非线性活性增加; 对具有相同共轭链的C₆₀-噻吩吡咯烷衍生物(2, 5, 1和4), 吸电子取代基减小了三阶光学非线性活性, 给电子基增大了三阶光学非线性活性; 同时发现喹啉环2-位键联(7)比4-位(8)有更好的三阶光学非线性活性.     

Measurements of light scattering changes induced by a strong optical field in solutions of tRNA

Changes in light scattering induced by a strong laser beam, as predicted theoretically by Kielich, were measured for unfractionated yeast transfer ribonucleic acid (tRNA) solutions. The vertically polarized electric field of a strong laser pulse (λ = 1060nm) amounted to 4.5 × 10³ esu cgs; its duration was 10 nsec. A weak incident laser beam (λ = 630nm) was also polarized vertically and the vertical and horizontal intensity components of the light scattered through 90° at the latter wavelength were measured. These measurements together with previous results from measurements of Rayleigh light scattering and light scattering in a magnetic field permitted evaluation of the tensor of third-order polarizability (c = 3 × 10^?30 esu cgs, c = ?373 × 10^?30 esu cgs) and the anisotropy of the third-order polarizability components with its sign (δ_c = +56 × 10^?2, δ_c = +0.25 × 10^?2 for tRNA monomer and aggregate, respectively). The new method described may be useful for studies of macromolecules and macromolecular complexes of biological importance.     

Study of light-scattering changes induced in tRNA solutions by a strong optical field of picosecond pulses

Changes in the light-scattering components (λ = 0.53 μm) induced by a strong picosecond optical field (λ = 1.06 μm) applied to macromolecular transfer ribonucleic acid (tRNA) solutions were studied. Two beams were polarized vertically, and the intensity of the vertical and horizontal components of the light (λ = 0.53 μm) scattered at an angle of 90° were measured. The electric field of the strong 30-ps laser pulse was 5.0 × 10³ esu cgs. The experimentally determined changes allowed for calculation of the mean third-order optical polarizability c, and its anisotropy δ_c. The measurements were performed in three different solutions: salt free, with magnesium ions, and without magnesium ions. Changes in tRNA structure reflected in changes of nonlinear light scattering, third-order optical polarizability, and its anisotropy were observed.     

具有高二阶极化率噻唑类生色分子的合成与表征

设计、合成了含羟乙基活性基团的噻唑类非线性生色分子, 用IR, EA, ¹H MNR, UV-Vis和DSC-TG等对其结构和性能进行了表征, 用超瑞利散射技术测定了其二阶极化率. 结果表明: 两种噻唑类生色分子具有较高的β值, 在波长1064 nm处, β分别为5.60×10^－28和5.76×10^－28 esu, 其最大吸收波长都未超过600 nm, 截止波长均小于710 nm, 生色分子的热分解温度分别为 224和216 ℃, 具有较好的热稳定性, 可用于制备性能优异的非线性光学材料.     

Design and synthesis of polyindole - ZnO nano composite for NLO applications

Present paper mainly focuses on the synthesis, characterization polyindole-ZnO nano composites for third order nonlinear optical applications. Polyindole was synthesized through oxidative polymerization technique and its composites were prepared with different ZnO concentration. Structural morphology of the polymer composite was studied using FESEM, XRD and UV Visible spectroscopic technique. Polymer showed broad absorption with absorption maxima of 395 nm. Newly prepared thin films showed excellent nonlinear absorption with very good optical limiting behaviour when it is exposed to He-Ne laser with maximum optical limiting power of 11 mW along with third-order nonlinear susceptibility χ⁽³⁾ of 2.72 × 10^?3 esu. Hence these polymer composites may be potential candidate for optical limiting applications.     

Study of Linear and Nonlinear Optical Properties of Four Derivatives of Substituted Aryl Hydrazones of 1,8‐Naphthalimide

Four 1,8‐naphthalimide hydrazone molecules with different electron‐donating groups have been applied in the study of linear and nonlinear optical (NLO) properties. These compounds showed strong green emission in solution. Their NLO properties such as two‐photon absorption (TPA) behavior with femtosecond laser pulses ca. 800 nm and excited‐state absorption (ESA) behavior with nanosecond laser pulses at 532 nm were investigated. Compound 4 presented the largest two‐photon cross section (550 GM) among them due to two factors: the conjugated length of compound 4 is the longest and the electron‐donating ability of compound 4 is the strongest. Different from TPA behavior, compound 2 showed the best nonlinear absorption properties at 532 nm and its nonlinear absorption coefficient and third‐order nonlinear optical susceptibilities χ ⁽³⁾ were up to 1.41×10^?10 MKS and 4.65×10^?12 esu, respectively. Through the modification of the structure, the nonlinear optical properties of these compounds at different wavelengths (532 and 800 nm) were well tuned. The great broad‐band nonlinear optical properties indicate hydrazones are good candidates for organic nonlinear optical absorption materials.     

HCO radical kinetics: Conjunction of laser photolysis and intracavity dye laser spectroscopy

HCO radical at a concentration of about 10¹⁴ cm^?3 is produced by monochromatic laser photolysis of H₂CO with a 0.6 mJ frequency-doubled, flashlamp-pumped dye laser pulse. Intracavity dye laser spectroscopy quantitatively monitors HCO absorbance near 614 nm as a function of delay time between photolysis and probing pulses. Rate constants for HCO + O₂ and HCO + NO are found to be 4.0 ± 0.8 × 10^?12 and 1.45 ± 0.2 × 10^?11 cm³ molecule^?1 sec^?1.     

Mercaptopyridine-substituted indium,zinc, and metal-free phthalocyanines: nonlinear optical studies in solution and on polymer matrices

In this article, the nonlinear optical characterizations and optical limiting properties of metal-free (2), zinc (3), and indium (4) tetra 4-(2-mercaptopyridine) phthalocyanines are discussed. Nonlinear optical properties of the samples were evaluated using Z-scan at 532 nm and 10 ns pulse in CHCl₃, and doped on poly(bisphenol A carbonate) (PBC) thin films. Thin films for 2, 3, and 4 are represented as 2-PBC, 3-PBC, and 4-PBC, respectively. We observed two-photon absorption (2PA) and strong reverse saturable absorption as the dominant mechanisms at nanosecond laser excitation in solution and thin films. By virtue of the magnitude of absorption coefficients and other nonlinear optical parameters estimated in this work, sample 4 was found to exhibit strongest nonlinear optical properties followed by 3, while 2 is the weakest nonlinear absorber of the studied samples. Large third-order susceptibility (1.46 × 10^?9 esu and 7.74 × 10^?10 esu) and hyperpolarizability (2.13 × 10^?28 and 8.37 × 10^?29 esu) were estimated for 4-PBC and 3-PBC, respectively. Our studies show that these molecules are suitable candidates for practical passive optical limiters.     

1,3,4-噁二唑衍生物的双光子吸收和双光子泵浦荧光

依据“推电子基-共轭中心-拉电子基-共轭中心-推电子基”的模型将电荷传输型1,3,4-噁二唑环嵌入芳香共轭体中, 通过Wittig-Horner反应合成了2种对称型强双光子吸收和双光子诱导荧光分子2,5-二[4-(2-芳基乙烯基)苯基]-1,3,4-噁二唑. 它们的氯仿溶液在锁模Nd: YAG激光器800 nm激光照射下, 发射出很强的双光子上转换荧光, 其最强荧光分别在波长507和475 nm. 采用非线性透过率法测得其双光子吸收截面分别为1.07×10^－46和6.6×10^－47 cm⁴•s•photon^－1. 这2个对称型D-π-A-π-D生色分子从激发端基到π共轭桥的有效能量传输, 对双光子吸收和双光子荧光发射能力贡献较大.     

Non‐Resonant z‐Scan Characterization of the Third‐Order Nonlinear Optical Properties of Conjugated Poly(thiophene azines)

The nonlinear optical properties of a functionalized poly(thiophene azine), namely, poly(3,4‐didodecylthiophene azine), PAZ, at the optical telecommunication wavelength of 1550 nm are investigated by means of the closed‐aperture z‐scan technique in both thin films and solutions. Values of χ⁽³⁾=(2.4±0.4)×10^?13 esu, n₂=(4.0±0.7)×10^?15 cm² W^?1, and γ=(4.5±0.7)×10^?34 esu are estimated for the third‐order (Kerr) susceptibility, the intensity‐dependent refractive index, and the molecular second hyperpolarizability of solution samples, respectively. A very small dependence on the polymer chain length is found. Markedly higher values of (4.4±1.1)×10^?11 esu, (6.6±1.0)×10^?13 cm² W^?1, and (5.0±0.8)×10^?33 esu are measured for the corresponding quantities in thick (up to 20 μm) polymer films cast on quartz plates. The enhancement of the NLO responses on going from solution to solid samples is attributed to a partially ordered structure and to the presence of interchain interactions leading to greater π‐electron delocalization in the cast polymer films. The results are compared with those previously obtained by using third‐harmonic generation (THG), taking into account that those data were measured under conditions of three‐photon resonance, whereas our z‐scan measurements are fully off‐resonance.     

1-二茂铁基-3-[(9-乙基)咔唑-3-基]丙烯酮的合成及三阶非线性光学性质

合成了一个新的非线性光学(NLO)有机材料1-二茂铁基-3-[(9-乙基)咔唑-3-基]丙烯酮(FCAK),并通过NMR、IR、MS和元素分析等技术手段进行了表征。 采用粉末Nd∶YAG激光技术测定了标题化合物的三阶非线性光学性质并确定了相关参数。 激光脉冲为4 ns时,非线性折射率n₂=-3.5×10^-18 m²/W,非线性吸收系数β=-2.7×10^-11 m/W,三阶非线性极化率χ⁽³⁾=2.04×10^-12 esu,三阶非线性分子超极化率γ=1.1×10^-30 esu。 激光脉冲为21 ps时,n₂=0.55×10^-18 m²/W,β=-0.6×10^-11 m/W,χ⁽³⁾=3.4×10^-13 esu,γ=0.13×10^-30 esu。