铁(Ⅲ)-邻菲罗啉溶液体系的光化学还原 Ⅱ.气相色谱法研究光化反应机理

关于Fe(Ⅲ)-邻菲罗啉(phen)溶液的光化学还原现象的记载可追溯到十九世纪末。     

反式二氯二L-苯丙氨酸乙酯合铂分子结构和晶体结构

反式二氯二L-苯丙氨酸乙酯合铂[Pt(C₁₁H₁₅NO₂)₂Cl₂]属单斜晶系,空间群为P2₁,α=13.555(6)?,b=6.487(3)?,c=15.588(5)?,β=109.42(3)°,Z=2。该化合物晶体结构由重原子法求解,用块矩阵最小二乘方法修正,R=0.0617,R_w=0.0575。Pt—N 2.065(14)?,2.084(14)?;Pt—Cl 2.285(7)?,2.312(8)?。结构由以N—H……O氢键联结的分子层交错堆积组成。 关键词：     

CRYSTAL AND MOLECULAR STRUCTURE OF N, N-PLATINUM-DIETHYL-DICHLORIDEDI-L-ASPARTATE

This paper reports the crystal and molecular structure of title compound. 3978 three-dimensional independent reflections were collected by Syntex R3 four circle diffractometer. The crystal is monoclinic with space group P2_1, a=8.074(1), b=11.309(4), c=27.793(9), β=106.84°(2), Z=4. The molecular formula is Pt(C_8 H_(15)O_4N)_a Cl_2. The crystal structure was solved by Patterson method and refined by block matrix least squares refinement techniques. The final R factor is 0.039.The result of crystal structure analysis shows that Pt(Ⅱ) has a dsp~2 hybrid orbital and square coordination. Two C1 atoms are located oppositely to two diethyi-dichloride-di-L-aspartare. N atoms have sp~3 tetrahedral hybrid configurations and form the coordinate bonds with Pt(Ⅱ) atom using their lone pair electrons. By reason of molecular packing and due to the formation of inner hydrogen bonds in the complex molecule, the configuration of L-aspartic acid in the title complex is more twisted than that of L-and DL-aspartic acid     

铁(Ⅲ)-邻菲哕啉溶液体系的光化学还原在分析化学上的应用——分光光度-光化学还原测铁法

用邻菲啰啉(phen)分光光度法测定Fe(Ⅱ)含量时,共存的Fe(Ⅲ)的光化还原作用,往往使结果波动较大。我们通过对Fe(Ⅲ)-phen溶液体系的光化学还原研究,建立了能连续而准确地测定试样中Fe(Ⅱ)和总铁含量的分光光度-光化学还原测铁法:试样用shapiro法溶解,测定Fe(Ⅱ)时,避光显色,消除了Fe(Ⅲ)的光化还原干扰;测定总铁时,用光化学还原代替加入还原剂的化学还原,操作简便、快速,结果准确、稳定。本文简要报道这一方法。     

α-氨基酸乙酯卤根合铂(II)的合成和构型研究

Sixteen new halogenoethylaminoacidato Pt(II) complexes were synthesized and characterized, of which eightiodo complexes (PtA2I2) (A = DL-a-AlaOEt, L-a-alaOEt, DL-a-PheOEt, L-a-PheOEt, DI-A-AspOEt, L-a-AspOEt, DL-a-SerOEt and L-a-Lys OEt), four chloro compounds (PtA2Cl2)(A = DL-a-PheOEt, DL-a-AspOEt, L-a-Asp OEt) and (DL-a-PheHOEt)2(PtCl4) were obtained by reaction of K2 (PtX4)(X = I^-, Cl^-) with the corresponding ethylaminoacidates in water. The other chlorethylaminoacidato Pt(II) complexes (PtA2Cl2) (A = DL-a-AlaOEt, L-a-AlaOEt, L-a-PheOEt, DL-a-Ser OEt) were synthesized in acetone by exchange reaction of the corresponding iodo complexes with AgCl in order to avoid hydrolysis of the ethyl aminoacidates. Molar conductivity determination showed that all the Pt(II) complexes obtained were neutral molecules with the exception of (DL-a-PheHOEt)2(PtCl4) which existed as an anion. As shown by diole moment determination and modified thiourea reaction, iodo complexes 1-7 and some of the chloro complexes (PtA2Cl2) (A = DL-a-alaOEt, D-a-AlaOEt, DL-a-SerOEt) were of cis-configuration and the other chloro complexes were of trans-configuration.     

硅钼黄—乙醇体系光化学还原硅钼蓝分光光度法测定硅

含０．８－２．０ｍｏｌ／Ｌ ＨＣｌ的硅钼黄－乙醇溶液体系在波长小于４６０ｎｍ的蓝紫光或紫外照射下，能够发生使硅钼黄定量还原为硅钼蓝的光化学反应。基于这一反应，研究建立了测试样品中硅含量的光化学还原硅钼蓝分光光度法。该法与化学还原硅钼蓝法相比，避免了因加入化学还原剂引起的干扰，重显性好，准确度高，操作简便，快速，测定结果的标准偏差≤０．０１２％，相对标准偏差≤１％。     

巧妙的提问 拨云见天日

美国教学法专家特林·G·卡尔汉认为：“提问是教师促进学生思维、评价教学效果以及推动学生实现预期目标的基本控制手段．”提问在初中数学课堂上是一种重要的教学手段,它是联系教师、学生与教材的纽带,是激发学生学习兴趣、开启学生智慧之门的钥匙,是沟通师生思维认识和产生情感共鸣的纽带．因此数学课堂教学应围绕问题来设计．     

α氨基酸乙酯卤根合铂(Ⅱ)的合成和构型研究

合成和鉴定了十六种新的含卤根的氨基酸乙酯的二价铂配合物。其中八种含碘配合物[PtA_2I_2](A=DL-α-AlaOEt,L-α-AlaOEt,DL-α-PheOEt,L-α-PheOEt,DL-α-AspOEt,L-α-AspOEt,DL-α-SerOEt)和[PtAI_2](A=L-α-LysOEt)以及部分含氯配合物[PtA_2Cl_2](A=DL-α-PheOEt,DL-α-ASpOEt,L-α-AspOEt)和(DL-α-PheHOEt)_2[PtCl_4]由K_2[PtX_4](X=I~-,Cl~-)与相应酯在水中作用而得。易水解的其它含氯氨基酸乙酯配合物[PtA_2Cl_2](A=DL-α-AlaOEt,L-α-AlaOEt,L-α-pheOEt,DL-α-serOEt)通过相应的含碘配合物[PtA_2I_2]与AgCl在非水体系(丙酮)中交换而成。摩尔电导率表明,除(DL-α-pheHOEt)_2[PtCl_4]外,所得配合物均为电中性。分子偶极矩测定和改良的硫脲反应确定了七种含碘配合物:三种含氯配合物[Pt(L-α-AlaOEt)_2Cl_2],[Pt(DL-α-AlaOEt)_2Cl_2]和[Pt(DL-α-SerOEt)_2Cl_2]为顺式构型,其余四种为反式构型的含氯苯丙氨酸乙酯或含氯天冬氨酸乙酯配合物。对决定配合物构型的主要因素进行了讨论。     

巧妙的数学实验 唯美的思维碰撞

《义务教育阶段数学课程标准（2011）》将传统的“双基”发展为“四基”,首次提出了数学基本活动经验的积累是提高学生数学素养的重要标志,帮助学生积累数学活动经验是数学教学的重要目标．要实现这样的教学目标,则就提倡科学探究的学习方式,而实验正是进行科学探究的主要方式．实验既可以激发学生学习的兴趣,又可以让学生获得新知识,验证巩固原有知识,更加重要的是它还能让学生学会科学的学习方法,提高科学探究的能力．