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11.
将有机物2,5-二溴对苯二甲酸(H2L1)和2,2′-联吡啶(L2)作为双配体,使用溶剂热法和七水合硫酸锌(ZnSO4·7H2O)、六水合硝酸钴(Co(NO3)2·6H2O)分别反应,得到配合物[Zn(L1)(L2)(H2O)]n(1)和配合物[Co(L1)(L2)(H2O)]n(2)。采用单晶X射线衍射、元素分析、红外光谱、紫外光谱、荧光光谱、热重分析等测试方法对这两种物质进行分析研究。单晶测试结果表明配合物1是单斜晶系,以Zn2+配位连接L2-1与L2形成一维链状结构,各条链在分子间氢键和π…π共轭作用下有规律地堆叠形成三维网络结构。配合物2是三斜晶系,Co1离子和Co1i离子由H2L1上的羧酸氧原子O4和O4i连接,形成双齿螯合的配位结构单元,以Co2+配位连接 L2-1和L2形成二维网格结构,各层在O—H…O分子间氢键和范德瓦耳斯力作用下有规律的堆叠形成三维网络结构。配合物1和2均含有芳香杂环、羧基杂环和氮杂环,具有良好的荧光性质和热稳定性,最大发射波长分别为345 nm和333 nm。 相似文献
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Haixing Guan Qianwen Zhang Prof. Dr. Patrick J. Walsh Prof. Dr. Jianyou Mao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(13):5210-5215
A unique nickel/organic photoredox co-catalyzed asymmetric reductive cross-coupling between α-chloro esters and aryl iodides is developed. This cross-electrophile coupling reaction employs an organic reductant (Hantzsch ester), whereas most reductive cross-coupling reactions use stoichiometric metals. A diverse array of valuable α-aryl esters is formed under these conditions with high enantioselectivities (up to 94 %) and good yields (up to 88 %). α-Aryl esters represent an important family of nonsteroidal anti-inflammatory drugs. This novel synergistic strategy expands the scope of Ni-catalyzed reductive asymmetric cross-coupling reactions. 相似文献
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Dr. Yong-Sheng Wei Dr. Liming Sun Miao Wang Dr. Jinhua Hong Dr. Lianli Zou Hongwen Liu Dr. Yu Wang Dr. Mei Zhang Dr. Zheng Liu Prof. Yinwei Li Prof. Satoshi Horike Prof. Kazu Suenaga Prof. Qiang Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16147-16156
Understanding the thermal aggregation behavior of metal atoms is important for the synthesis of supported metal clusters. Here, derived from a metal–organic framework encapsulating a trinuclear FeIII2FeII complex (denoted as Fe3) within the channels, a well-defined nitrogen-doped carbon layer is fabricated as an ideal support for stabilizing the generated iron nanoclusters. Atomic replacement of FeII by other metal(II) ions (e.g., ZnII/CoII) via synthesizing isostructural trinuclear-complex precursors (Fe2Zn/Fe2Co), namely the “heteroatom modulator approach”, is inhibiting the aggregation of Fe atoms toward nanoclusters with formation of a stable iron dimer in an optimal metal–nitrogen moiety, clearly identified by direct transmission electron microscopy and X-ray absorption fine structure analysis. The supported iron dimer, serving as cooperative metal–metal site, acts as efficient oxygen evolution catalyst. Our findings offer an atomic insight to guide the future design of ultrasmall metal clusters bearing outstanding catalytic capabilities. 相似文献
14.
Paired single residue‐transposed Lys‐N and Lys‐C digestions for label‐free identification of N‐terminal and C‐terminal MS/MS peptide product ions: ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry and tandem mass spectrometry for peptide de novo sequencing 下载免费PDF全文
15.
利用沙漠沙独特的化学组成特性和矿物特性,将沙漠沙荒料作为硅源,工业Al(OH)3作为铝源制备莫来石晶须.改变硅源/铝源配比和合成温度,结合XRD、SEM、TEM研究莫来石生长环境和自由生长形态的变化.研究结果表明:当沙漠沙与Al(OH)3的质量比为35/65时,在1200℃的低温下就能获得平均值>60的高长径比莫来石晶须;随着煅烧温度的升高,莫来石晶须长径比不断增大,当温度升至1300℃,平均长径比>94.随着合成温度的升高,莫来石的形成经过了一次莫来石和二次莫来石化两个阶段;若配方中Al2 O3处于过饱和状态,样品中刚玉相会随着煅烧温度的升高出现先增多后降低的变化现象. 相似文献
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18.
Qin Yin Shou-Guo Wang Xiao-Wei Liang De-Wei Gao Jun Zheng Shu-Li You 《Chemical science》2015,6(7):4179-4183
An organocatalytic asymmetric chlorinative dearomatization of naphthols was realized for the first time, providing chiral naphthalenones with a Cl-containing all-substituted stereocenter in excellent yields and enantioselectivity (up to 97% yield and 96% ee). The reaction features mild reaction conditions, good tolerance of diverse functional groups and simple reaction operation. 相似文献
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20.
Mass concentration and isotopic values δ13C and 14C are presented for the water-insoluble refractory carbon(WIRC) component of total suspended particulates(TSP),collected weekly during 2003,as well as from October 2005 to May 2006 at the WMO-GAW Mt.Waliguan(WLG) site.The overall average WIRC mass concentration was(1183±120)ng/m3(n = 79),while seasonal averages were 2081 ±1707(spring),454±205(summer),650±411(autumn),and 1019±703(winter) ng/m3.Seasonal variations in WIRC mass concentrations were consistent with black carbon measurements from an aethalometer,although WIRC concentrations were typically higher,especially in winter and spring.The δ13C PDB value(-25.3 ± 0.8)%.determined for WIRC suggests that its sources are C3 biomass or fossil fuel combustion.No seasonal change in δ13C PDB was evident.The average percent Modern Carbon(pMC) for 14C in WIRC for winter and spring was(67.2 ± 7.7)%(n = 29).Lower pMC values were associated with air masses transported from the area east of WLG,while higher pMC values were associated with air masses from the Tibetan Plateau,southwest of WLG.Elevated pMC values with abnormally high mass concentrations of TSP and WIRC were measured during a dust storm event. 相似文献