A Strong-Acid-Resistant [Th6] Cluster-Based Framework for Effectively and Size-Selectively Catalyzing Reductive Amination of Aldehydes with N,N-Dimethylformamide

Utilization of N,N-dimethylformamide (DMF) as an amine source and reductant for synthesizing tertiary amines is a promising way to replace the substrates formaldehyde and dimethylamine, and it is desirable to seek porous acid-resistant catalysts for heterogeneous catalysis of this reaction. Herein, a robust metal–organic framework (MOF) {[Th₆O₄(OH)₄(H₂O)₆(BCP)₃]⋅10 DMF}_n ( 1 ) containing stacked nanocages with a diameter of 1.55 nm was constructed. Compound 1 can maintain its single-crystal structure even kept in air at 400 °C for 3 h, and in DMF or water at 200 °C for 7 days. Density functional theory (DFT) calculations suggested that the high interaction energy between the [Th₆O₄(OH)₄(H₂O)₆]¹²⁺ clusters and ligands was responsible for the excellent stability of 1 . Catalytic investigations revealed that 1 can effectively and size-selectively catalyze the reductive amination of aldehydes with DMF, and it can be reused at least five times without obvious loss in catalytic activity.     

异核双金属探针在活细胞细胞核和线粒体中选择性定位DNA

用于实时成像活细胞DNA的细胞核探针是非常罕见的。通过Ru(N^N)₃、Ir(C^N)₂(N^N)、Re(CO)₃Cl(N^N)和Pt(C^N)(N^N)的结合,生成了4种异核双金属配合物：2种不同的功能金属位点被锚定在线性双齿螯和配体(N^N)-(N^N)的尾端,形成不对称哑铃状的双金属分子M₁-M₂,即Ru-Re、Ru-Pt、Ir-Re和Ir-Pt。Ru-Re和Ru-Pt的红色发射探针具有较大的斯托克斯位移、优异的核膜穿透能力、良好光稳定性的DNA结合能力。此外,Ru-Re和Ru-Pt探针的DNA成像可与专门用于活细胞细胞核DNA染色的Hoechst 33342商用染料相媲美,而Ir-Re和Ir-Pt探针直接靶向线粒体。不同探针的发光特性和选择性胞内定位高度依赖于在异核双金属配合物中的金属物种。     

1,8-萘酰亚胺衍生物的合成、表征及电存储性能

本文以三苯胺结构作为电子给体,与三种接有不同吸电子基团的1,8-萘酐反应合成了具有电子给-受体结构的N-(4-三苯胺)-1,8-萘酰亚胺(NA-ATPA)、N-(4-三苯胺)-(4-氰基)-1,8-萘酰亚胺(NA(CN)-ATPA)和N-(4-三苯胺)-(4-硝基)-1,8-萘酰亚胺(NA(NO_2)-ATPA),并对它们的结构进行了表征。利用紫外可见光谱、荧光发射光谱和循环伏安法对产物的光物理性能和电化学性能进行了测试,并测试了其存储行为,结果显示NA-ATPA表现出易失的静态随机存储行为(SRAM),NACN-ATPA表现出非易失的闪存型存储(Flash),NA(NO_2)-ATPA表现出非易失只读型存储(WORM)。三种萘酰亚胺对存储行为中高导态的维持能力逐渐增强,其原因是引入的吸电子基团的吸电子性越强,其LUMO值和能隙值降低的越多,越利于电荷转移,形成更稳定的电荷转移络合物。另外,本文还对原料和产物的电子结构、分子轨道和能级进行了分子模拟计算,研究了三种化合物基态和激发态的差别,并对其电子转移过程进行了理论分析。     

硫酸锌与L-α-氨基酸配合行为的相化学研究

锌是人体必需的微量元素之一,L－α－氨基酸是人体必需的氨基酸,是组成蛋白质的结构单元．α－氨基酸锌作为添加剂在药物、食品和化妆品中有广阔的应用前景［1.2］．有关氨基酸锌的合成方法前文［3］已述及．用相平衡方法研究锌盐与氨基酸的配合行为的相化学,可提供它们之间能否形成配合物,能形成几种计量比的配合物以及其相区大小和性质等信息,对新型配合物,特别是固液异成分化合物的合成具有指导意义．本文对ZnSO4与3种人体必需而非自生的L－Met,L－Phe和L－His在水中的相化学进行了研究,在相图指导下合成了新化合物并进行了…     

用微量热法测定稀土含硫有机配合物的比热容

推导了用改进的RD496-III型微热量计测定固态物质比热容的计算式. 用Joule 效应确定了仪器在298.15 K时的量热常数和相对标准偏差分别为(63.901±0.030) μV•mW^－1和0.08%, 用Peltier效应测定总不平衡热. 在该仪器上测定的两种标准物质(基准苯甲酸和α-Al₂O₃)比热容的计算值与文献值相差在0.4%以内. 用本法测定了13种固态配合物RE(PDC)₃(phen) (RE＝La, Pr, Nd, Sm～Lu; PDC＝ )的比热容值, 总偏差在1.0%, 与稀土原子序数Z_RE作图呈现“三分组现象”, 说明配合物中RE^3＋与配体间的化学键有一定程度的共价性, 显示了稀土离子4f电子云的扩大效应.     

三元配合物Tm[(C5/sub>H8NS2)3(C12H8N2)]的热化学性质研究

在无水乙醇中，用吡咯烷二硫代氨基甲酸铵(APDTC)和1,10-邻菲咯啉(o-phen·H₂O)与TmCl₃·3.65H₂O作用，合成了未见文献报道的三元固态配合物，确定它的组成为Tm[(C_{5/sub>H8NS2)3(C12H8N2)]。 用RD496-Ⅲ微量热计测定了298.15 K下水合氯化铥及两个配体在无水乙醇中的溶解焓，两个配体醇溶液的混合焓及不同温度下标题化合物液相生成反应的焓变。在实验和计算基础上，得到了液相生成反应的热力学参数(活化焓、活化熵和活化自由能)，速率常数和动力学参数(表现活化能、频率因子和反应级数)。通过合理的热化学循环，求得了298.15 K时标题化合物的固相生成反应焓变；推导了用该热量计测定固态物质比热容的计算式，并测定了题目配合物298.15 K的比热容。用RBC-Ⅱ精密转动弹热量计测定了题目配合物的恒容燃烧热， 计算了它们的标准摩尔燃烧焓和标准摩尔生成焓。}     

ZnCl2-氨基酸 (Leu/Try/Val/Thr)-H2O体系的等温溶度

The solubility properties of the zinc chloride amino acids(Leu/Try/ Val/Thr) water systems at 25 ℃ in the whole concentration range have been investigated by equilibrium method, the corresponding phase diagrams and refractive index curves were constructed. The results indicate the formation of the congruently soluble compound of Zn(Leu)Cl2（A） in Leu system and the incongruently soluble compounds of Zn(Try)Cl2•1/2H2O(B)、 Zn(Val)Cl2 •H2O(C)、 Zn(Val)2Cl2(D)、 Zn(Thr)Cl2•H2O(E) and Zn(Thr)2Cl2(F) in Try/Val/Thr systems, which have not been reported in literature. According to the phase equilibrium result, six solid complexes have been prepared in water, and their compositions have been determined by chemical analysis which are consistent with the results of phase diagrams.     

Integral closure of a cubic extension and applications

In this paper, we compute the integral closure of a cubic extension over a Noetherian unique factorization domain. We also present some applications to triple coverings and to rank two reflexive sheaves over an algebraic variety.

     

Annealing effect of platinum-incorporated nanowires created by focused ion/electron-beam-induced deposition

Focused ion-beam-induced deposition(FIBID) and focused electron-beam-induced deposition(FEBID) are convenient and useful in nanodevice fabrication. Since the deposition is from the organometallic platinum precursor, the conductive lines directly written by focused ion-beam(FIB) and focused electron-beam(FEB) are carbon-rich materials. We discuss an alternative approach to enhancing the platinum content and improving the conductivity of the conductive leads produced by FIBID and FEBID, namely an annealing treatment. Annealing in pure oxygen at 500?C for 30 min enhances the platinum content values from ～18% to 30% and ～ 50% to 90% of FIBID and FEBID, respectively. Moreover, we find that thin films will be formed in the FIBID and FEBID processes. The annealing treatment is helpful to avoid the current leakage caused by these thin films. A single electron transistor is fabricated by FEBID and the current–voltage curve shows the Coulomb blockade effect.     

Construction of metal–organic frameworks with transitional metals based on the 3,5-bis(4-pyridyl)-1H-1,2,4-triazole ligand

Based on the versatile ligand 3,5-bis(4-pyridyl)-1H-1,2,4-triazole (Hbpt) derived from an in situ metal/ligand reaction, a series of coordination compounds CoCl₄(H₃bpt)(H₂O) (1), Cu(H₂bpt)₂(SO₄)₂(H₂O)₆ (2), [Ag(bpt)]_n (3), [Co(Hbpt)(pa)]_n (4), [Co(Hbpt)(pda)]_n (5) and [Cu(Hbpt)(pda)(H₂O)]_n (6) have been constructed (pa = phthalate, pda = 1,3-phenylenediacetate). The structures of these targeted complexes have been characterized by X-ray single-crystal diffraction techniques. Structural analysis reveals that Hbpt adopts versatile coordination modes to arrange the metal ions in 0-D point, simple (4,4) layers and dinuclear core chains in 1–3, which are further extended via the benzenedicarboxylate connectors to give rise to a variety of coordination networks such as (4,4), (4¹² · 6³), (6⁴ · 8²) topologies in 4–6. The supramolecular organization through hydrogen bonds is analyzed for these complexes and thermal stability of these crystalline materials has been explored by TG-DTG.