微波辐射法合成NaX分子筛

NaX是低硅铝比的八面沸石,一般在低温水热条件下合成.因反应混合物配比不同,以及采用的反应温度不同,晶化时间为数小时至数十小时不等. 近年来,微波辐射方法被应用于无机及有机化合物的合成中.Chu Pochen等在专利文献中报道了微波辐射法在沸石分子筛合成中的应用,其中提到了NaX分子筛,但对合成     

两个镉的配位聚合物的原位水热合成、晶体结构与荧光性质

在水热条件下, 以3-氨基-1,2,4-三唑-5-甲酸(AmTHZAC)为配体, 原位反应得到了两个镉的配位聚合物 Cd(AmTAZ)Cl(1)和[Cd(AmTAZ)(BDC)(H2O)2]·1.25H2O(2)(AmTAZH=3-amino-1,2,4-triazole, H2BDC=benzene-1,4-dicarboxylic acid), 采用红外光谱、差热-热重、CHN元素分析及单晶X射线衍射等手段对晶体结构进行了表征, 并研究了化合物1和2的荧光性质. 化合物1属正交晶系, P2(1)2(1)2(1)空间群, a=0.6452(3) nm, b=0.7848(5) nm, c=1.0449(6) nm, V=0.5291(5) nm3, Z=4, 最后一致性因子[I＞2σ(I)], R1=0.0226, wR2=0.0377, GOF=1.087. 化合物2属正交晶系, Pmc2(1)空间群, a=0.7100 nm, b=0.9920 nm, c=1.2561 nm, V=0.8847 nm3, Z=8, 最后一致性因子[I＞2σ(I)], R1=0.0934, wR2=0.2456, GOF=1.031.     

元素化学课程思政案例库建设及线上线下混合递进式教学实践

教学团队立足元素化学课程特点,设计、建设了“科学”“人文”“思政”三融合的元素化学课程思政案例库,并将之融入线上线下混合递进式教学的各个阶段和环节,以同步实现知识传授、能力培养、价值塑造三位一体的教学目标。同时,建立课程思政的集体教研制度,确保课程思政的整体性和持续性。     

具有3个次级晶格结构的钛酸盐晶体[Ni(OH)1.115(H2O)0.885]1.22(Ti1.73O4)·1.65H2O的合成

以K0.81Li0.27Ti1.73O4为前驱物, 通过水热方法合成出一种新型多晶格化合物[Ni(OH)1.115(H2O)0.885]1.22(Ti1.73O4)·1.65H2O. 应用XRD, IR, TG-DTA和TEM等测试方法对该化合物进行了表征. 结果表明, 在该化合物中, TiO2层和Ni(OH)2层沿c方向交替堆积, 分别形成3个次级晶格. 其中TiO2次级晶格属于正交晶系, 其可能的空间群是Pmmm, 晶格参数a=0.3875 nm, b=0.2976 nm, c=2.288 nm和α=β=γ=90°. 另外2个Ni(OH)2次级晶格具有相同的大小和对称性, 晶格参数a=b=0.3140 nm, c=2.288 nm, α=β=90°, γ=120°. TiO2次级晶格和Ni(OH)2次级晶格在ab平面二维方向上不匹配.     

Quantum-chemical predictions of redox potentials of organic anions in dimethyl sulfoxide and reevaluation of bond dissociation enthalpies measured by the electrochemical methods

A first-principle theoretical protocol was developed that could predict the absolute pK(a) values of over 250 structurally unrelated compounds in DMSO with a precision of 1.4 pK(a) units. On this basis we developed the first theoretical protocol that could predict the standard redox potentials of over 250 structurally unrelated organic anions in DMSO with a precision of 0.11 V. Using the two new protocols we systematically reevaluated the bond dissociation enthalpies (BDEs) measured previously by the electrochemical methods. It was confirmed that for most compounds the empirical equation (BDE = 1.37 pK(HA) + 23.1E(o) + constant) was valid. The constant in this equation was determined to be 74.0 kcal/mol, compared to 73.3 kcal/mol previously reported. Nevertheless, for a few compounds the empirical equation could not be used because the solvation energy changed dramatically during the bond cleavage, which resulted from the extraordinary change of dipole moment during the reaction. In addition, we found 40 compounds (mostly oximes and amides) for which the experimental values were questionable by over 5 kcal/mol. Further analyses revealed that all these questionable BDEs could be explained by one of the three following reasons: (1) the experimental pK(a) value is questionable; (2) the experimental redox potential is questionable; (3) the solvent effect cannot be neglected. Thus, by developing practical theoretical methods and utilizing them to solve realistic problems, we hope to demonstrate that ab initio theoretical methods can now be developed to make not only reliable, but also useful, predictions for solution-phase organic chemistry.     

NH4ZnPO4的非水合成与晶体结构

从非水体系中制得ＮＨ４ＺｎＰＯ４单晶，并用Ｘ线测定了晶体结构；晶体属六方晶系，Ｐ６３空间群，晶胞参数；ａ＝１．０６８８（２）ｎｍ，ｃ＝８７０６（２）ｎｍ，Ｚ＝８，Ｄｃ＝２．７５１ｇ．ｃｍ＾－３，结构中的锌和磷均为四面体本位，且严格交替排列，无Ｚｎ－Ｏ－Ｚｎ和Ｐ－Ｏ－Ｐ联结方式。     

[Pb6(H2O)2(cit)4]·3H2O和Pb(tar)(H2O)2两种柔性酸和铅的配位聚合物的水热合成与表征

在水热条件下, 合成了2个含柔性配体柠檬酸和酒石酸的二价铅配位聚合物[Pb6(H2O)2(cit)4]·3H2O(1)(H3cit=citric acid)及Pb(tar)(H2O)2(2)(tar=tartaric acid). 用红外光谱、差热-热重、元素分析、粉末X射线衍射及单晶X射线衍射等手段对化合物进行了表征. 化合物1属三斜晶系, P1空间群, a=0.97053(19) nm, b=0.9764(2) nm, c=1.0955(2) nm, α=109.016(3)°, β=98.380(3)°, γ=92.136(3)°, V=0.9671(3) nm3, Z=2, R1=0.0420, wR2=0.1049, GOF=1.064. 在化合物1的不对称结构单元中, 有3个铅离子以及2个柠檬酸阴离子和2个游离的水分子. 铅离子分别以4, 5, 7配位与柠檬酸配合形成了中性的三维骨架结构. 化合物2属于正交晶系, Pbca空间群, a=1.39739(6) nm, b=0.64922(2) nm, c=1.80354(10) nm, V=1.63620(13) nm3, Z=8, R1=0.0283, wR2=0.0649, GOF=1.014. 在化合物2的不对称结构单元中, 有1个铅离子、1个酒石酸分子和1个水分子, 六配位的铅和酒石酸形成了一维外消旋的无限长链, 链与链之间通过氢键连接成一个三维超分子结构. 在化合物1和2中, 两种配体均出现了α羟基和α羧基螯合的配位模式, 铅的6s孤电子对均显示了立体化学活性, 使配位键分布于半球区域.     

有机磷试剂在肽合成中的应用

本文综述有机磷试剂在肽合成中的应用情况,介绍了各种用作氨基保护试剂的磷(膦)酰氯及硫代膦酰氯和四价鏻盐;并着重介绍了不同价态的有机磷试剂用于羧基活化的发展状况。 . t     

C4H8N2H4·Zn(HPO3)2的水热合成和结构表征

在过去的十几年中 ,人们对含有机模板的、由 Zn O4 四面体和 PO4 四面体基本结构单元组成的磷酸锌盐进行了深入广泛的研究 ,发现其结构具有多样性 [1] .近年来 ,人们又开始探索用亚磷酸氢根( HPO3)替代磷酸根 ( PO4 ) ,形成结构新颖的含有机模板的亚磷酸盐 .与磷酸根相比 ,亚磷酸氢根只能与 3个邻近的阳离子通过 P— O— M( M=Zn等 )键相连 ,结构同 [PO3( OH) ]相似 .鉴于此 ,HPO3完全可以作为搭建空旷骨架化合物的结构基元 .与磷酸盐的研究相比 ,以有机胺为模板的过渡金属亚磷酸盐合成研究相对较少 .Harrison等 [2 ,3] 报道了通过…     

Hydrothermal Syntheses and Structural Characterization of One-Dimensional [Cu4Br2I3(C12H8N2)2] n and Molecular Cu3Br3(C12H8N2)2

The hydrothermal reactions of CuBr₂, CuX (X=Br, I), and phen (phen=1,10-phenanthroline, C₁₂H₈N₂) have lead to the syntheses of two novel complexes of one-dimensional [Cu₄Br₂I₃(phen)₂] _n 1 and trinuclear discrete cluster Cu₃Br₃(phen)₂ 2. Both compounds were characterized by singe-crystal X-ray diffraction. Crystal data for 1. Monoclinic, space group P2 ₁/c with a=14.054(3) Å, b=13.700(3) Å, c=15.920(3) Å, =114.16(3)°, Z=2; 2. Monoclinic, space group C2/c with a=10.040(2) Å, b=14.516(3) Å, c=16.319(3) Å, =94.29(3)°, Z=6.