软硬酸碱规则与体内微量元素

阐述了ＳＨＡＢ规则,分类,酸碱软硬度的定量标度和理论解释。根据ＳＨＡＢ规则把体内微量元素分为Ｌｅｗｉｓ硬酸,软酸与交界酸和硬碱,软碱与交界碱,体内不同体液和器官含有丰富的软硬配体,与各类软硬酸（金属离子）结合成不同稳定性的配合物,发挥其生物活性作用。     

Controlled Cationic Polymerization of 1‐Methoxy‐1,3‐Butadiene: Long‐Lived Species‐Mediated Reaction and Control over Microstructure with Weak Lewis Bases

Controlled cationic polymerization of trans‐1‐methoxy‐1,3‐butadiene was achieved through the design of appropriate initiating systems, yielding soluble polymers with controllable molecular weights. The combined use of SnCl₄ or GaCl₃ as a Lewis acid catalyst and a weak Lewis base in conjunction with HCl as a protonogen resulted in efficient and controlled polymerization. The M_n values of the product polymers increased linearly along the theoretical line, which indicates that intermolecular crosslinking reactions negligibly occurred. In addition, the polymer microstructure was critically dependent on the weak Lewis base employed. In particular, the use of tetrahydrofuran as an additive resulted in the highest 4,1/4,3‐structure ratio (96/4). Weak Lewis bases also affected the polymerization rates but exhibited unique trends that differed from their effects on the cationic polymerization of alkyl vinyl ethers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 288–296     

Metal-Free Catalytic Formation of a Donor-Acceptor-Donor Molecule and Its Lewis Acid-Adduct Singlet Diradical with High-Efficient NIR-II Photothermal Conversion

We have synthesized a quinone-incorporated bistriarylamine donor-acceptor-donor (D–A–D) semiconductor 1 by B(C₆F₅)₃ (BCF) catalyzed C−H/C−H cross coupling via radical ion pair intermediates. Coordination of Lewis acids BCF and Al(OR^F)₃ (R^F=C(CF₃)₃) to the semiconductor 1 afforded diradical zwitterions 2 and 3 by integer electron transfer. Upon binding to Lewis acids, the LUMO energy of 1 is significantly lowered and the band gap of the semiconductor is significantly narrowed from 1.93 eV ( 1 ) to 1.01 eV ( 2 ) and 1.06 eV ( 3 ). 2 and 3 are rare near-infrared (NIR) diradical dyes with broad absorption both centered around 1500 nm. By introducing a photo BCF generator, 2 can be generated by light-dependent control. Furthermore, the integer electron transfer process can also be reversibly regulated via the addition of CH₃CN. In addition, the temperature of 2 sharply increased and reached as high as 110 °C in 10 s upon the irradiation of near-infrared-II (NIR-II) laser (1064 nm, 0.7 W cm⁻²), exhibiting a fast response to laser. It displays excellent photothermal stability with a photothermal (PT) conversion efficiency of 62.26 % and high-quality PT imaging.     

Polystyrene-supported TiCl4 as a novel,efficient and reusable polymeric Lewis acid catalyst for the chemoselective synthesis and deprotection of 1,1-diacetates under eco-friendly conditions

Copolymer beads of styrene and divinylbenzene (5–7%) were synthesized and combined with titanium tetrachloride in CS₂ to form a stable complex. The PS/TiCl₄ complex was used as a mild and efficient polymer-supported Lewis acid catalyst for the preparation of 1,1-diacetates from various types of aldehydes under heterogeneous conditions at room temperature. Deprotection of the resulting 1,1-diacetates has also been achieved using the same catalyst in methanol. This new protocol has the advantages of easy availability, stability, reusability of the eco-friendly catalyst, high to excellent yields, chemoselectivity, simple experimental and work-up procedure. Moreover, this polymeric catalyst could be recovered easily and reused several times without significant loss in activity.     

Synthesis and Inclusion Properties of a Novel Thiacalix[4]arene-Based Hard–Soft Receptor with 1,3-Alternate Conformation

A novel ditopic receptor possessing two complexation sites and bearing 1,3-alternate conformation based on thiacalix[4]arene was prepared. The binding behaviors with alkali metals and silver ion have been examined by ¹H NMR titration experiment. Although the formation of the heterogeneous dinuclear complexes was not observed, the exclusive formation of mononuclear complexes of 1,3-alternate-3 with metal cations is of particular interest in negative allosteric effect in the thiacalix[4]arene family. These findings demonstrate that preorganization, subtle conformational changes and affinity have a pronounced effect on the complexation process between the two different arms placed at the two edges of the thiacalix[4]arene cavity.     

环单体的合成,聚合及与环氧树脂的固化反应

合成了新螺环原碳酸酯单体：３，９－二（对甲氧基苄基）－１，５，７，１１－四氧杂螺环［５，５］十一烷。以ＢＦ３·ＯＥｔ２为催化剂，实现了其阳离子聚合。聚合产物的＾１Ｈ ＮＭＲ、＾１３Ｃ ＮＭＲ、ＩＲ及元素分析均表明发生了双开环聚合反应。探讨了其聚合历程。用ＤＳＣ和ＩＲ跟踪环氧树脂及其与螺环单体混合后的固化反应过程，研究了固化剂、反应条件对固化反应的影响。     

螺环单体的合成、聚合及与环氧树脂的固化反应

合成了新螺环原碳酸酯单体：３，９－二（对甲氧基苄基）－１，５，７，１１－四氧杂螺环［５，５］十一烷．以ＢＦ３·ＯＥｔ２为催化剂，实现了其阳离子聚合．聚合产物的１ＨＮＭＲ、１３ＣＮＭＲ、ＩＲ及元素分析均表明发生了双开环聚合反应．探讨了其聚合历程．用ＤＳＣ和ＩＲ跟踪环氧树脂及其与螺环单体混合后的固化反应过程，研究了固化剂、反应条件对固化反应的影响     

Lewis Acid Behavior of SF4: Synthesis,Characterization, and Computational Study of Adducts of SF4 with Pyridine and Pyridine Derivatives

Sulfur tetrafluoride was shown to act as a Lewis acid towards organic nitrogen bases, such as pyridine, 2,6‐dimethylpyridine, 4‐methylpyridine, and 4‐dimethylaminopyridine. The SF₄?NC₅H₅, SF₄?2,6‐NC₅H₃(CH₃)₂, SF₄?4‐NC₅H₄(CH₃), and SF₄?4‐NC₅H₄N(CH₃)₂ adducts can be isolated as solids that are stable below ?45 °C. The Lewis acid–base adducts were characterized by low‐temperature Raman spectroscopy and the vibrational bands were fully assigned with the aid of density functional theory (DFT) calculations. The electronic structures obtained from the DFT calculations were analyzed by the quantum theory of atoms in molecules (QTAIM). The crystal structures of SF₄?NC₅H₅, SF₄?4‐NC₅H₄(CH₃), and SF₄?4‐NC₅H₄N(CH₃)₂ revealed weak S?N dative bonds with nitrogen coordinating in the equatorial position of SF₄. Based on the QTAIM analysis, the non‐bonded valence shell charge concentration on sulfur, which represents the lone pair, is only slightly distorted by the weak dative S?N bond. No evidence for adducts between quinoline or isoquinoline with SF₄ was found by low‐temperature Raman spectroscopy.     

Synthesis of epigallocatechin trimer, (epigallocatechin)2-epicatechin,and (epigallocatechin)2-catechin via a Lewis acid mediated one-pot condensation and their antitumor activities in prostate cancer cells

Syntheses of epigallocatechin trimer, (epigallocatechin)₂-epicatechin and (epigallocatechin)₂-catechin were achieved. The key condensation to form the proanthocyanidin trimer derivatives was accomplished in a one-pot procedure using a dimeric epigallocatechin electrophile, which was prepared in situ by self-condensation of an epigallocatechin derivative, and an epigallocatechin, epicatechin, or catechin derivative as the nucleophile in the presence of a Lewis acid. The epigallocatechin monomer to trimer compounds containing a pyrogallol group significantly suppressed cell proliferation in PC-3 prostate cancer cells.     

Synthesis,Structure, and Catalytic Activity of Cyclometalated Iridium Complexes with a Bidentate POC Ligand

Synthesis, characterization and catalytic activity of cyclometalated iridium complexes with a bidentate POC ligand is presented. Metalation of POC-H (di-tert-butyl(phenoxy)phosphane) with [Ir(COD)Cl]₂ proceeded rapidly at room temperature and afforded mixture of (POC)(POC-H)IrHCl ( 1 a ) and (POC)(COD)IrHCl ( 1 b ), from which complexes (POC)(L)IrHCl where L=PPh₃ ( 1 c ), bipyridine ( 1 d ) and [2,2′-bipyridine]-6,6′-diol ( 1 e ) were prepared through ligand exchange. The compounds were tested in acceptorless dehydrogenation of 1-phenylethanol and transfer dehydrogenation of ethanol in a context of comparison with pincer counterparts (POCOP)IrHCl and (PCN)IrHCl. An attempt to prepare a dihydride complex from 1 e led to dimeric complex [(POC)(bipy-diol−)IrH]₂ ( 3 ) that could explain the low activity of 1 e . DFT studies provided insight into POC-H vs POCOP-H metalation mechanism.     

Chiral Recognition in π Complexes of Alkenes,Aldehydes, and Ketones with Transition Metal Lewis Acids; Development of a General Model for Enantioface Binding Selectivities

Prochiral alkenes, aldehydes, and ketones constitute the most frequently used starting materials for enantioselective organic syntheses. Protocols often involve chiral binding agents or Lewis acids that can give two diastereomeric adducts, the ratios of which are measures of chiral recognition. With π adducts, the diastereomers differ in the enantioface of the C?C or O?C group bound to the Lewis acid. This review provides the first comprehensive analysis of such equilibria and related binding phenomena with chiral transition metal Lewis acids. An extensive body of data from the authors' laboratory for complexes of the pyramidal rhenium fragment [(η⁵?C₅H₅)Re(No)(PPh₃)]⁺ ( I ) affords particular insight. Literature data for other complexes are also summarized. A general model for chiral recognition based upon the relative steric properties of four quadrants is presented. This enables binding selectivities to be individually and rationally optimized for different classes of ligands. Electronic effects are also identified and correlated with specific structural properties. Relationships between binding equilibria, reactivity, and product configurations are discussed.     

混合钴源对Co-Pd/TiO2催化剂催化CH4-CO2两步梯阶转化法合成乙酸的性能影响

以混合钴源为前驱体, 采用等体积浸渍法制备了Co-Pd/TiO2催化剂, 考察了其对CH4和CO2梯阶转化直接合成乙酸的催化性能, 采用XRD, XPS, NH3-TPD和BET对催化剂进行了表征. 结果表明, 催化剂具有适宜的表面酸性、 高比表面积和孔结构, 有利于提高催化剂的活性. 在m(CoCl2)∶m=2∶5, m(Co)∶m(Pd)=2∶1, 常压, 150 ℃条件下, 乙酸的生成速率达到6.13 mg·g-1Cat·h-1, 选择性达到 81.6%, 分别比以单一Co源制备的催化剂提高了134%和16%.     

镧系元素Dawson结构钨钒磷四元杂多配合物的合成、表征以及对H2O2分解的催化活性

合成了通式为K₁₅H₃[Ce(P₂W₁₆VO₆₁)₂]·61H₂O、K₁₅H₄[Ln(P₂W₁₆VO₆₁)₂]·xH₂O(Ln=La³⁺,Pr³⁺,Nd³⁺,Sm³⁺,Eu³⁺,Gd³⁺,Dy³⁺,Yb³⁺)的9种镧系元素Dawson结构的钨钒磷四元杂多配合物,并用IR、UV、NMR、ESR、XRD、TG-DTA等对其结构和性质进行了研究。该类配合物具有与K₁₆[Ce(P₂W₁₇VO₆₁)₂]·50H₂O类似的结构,对H₂O₂分解有较高的催化活性。     

Synthesis and Characterization of the Lewis Acid‐Base Complexes SbCl5 · LB (LB = ICN,BrCN, ClCN, 1/2(CN)2, NH2CN,Pyridine) – a Combined Theoretical and Experimental Investigation. The Crystal Structures of SbCl5 · NCCl and SbCl5 · NCCN · SbCl5

The Lewis acid‐base complexes SbCl₅ · LB (LB = ICN, BrCN, ClCN, ¹/₂(CN)₂, NH₂CN, pyridine) were prepared. The products formed were characterized by Raman and NMR spectroscopy. Density functional theory (B3LYP) was applied to calculate structural and vibrational data. Vibrational assignments of the normal modes for these Lewis acid‐base adducts was made on the basis of their Raman spectra in comparison with computational results. The stability of the complexes was investigated by calculating the bond dissociation enthalpy. SbCl₅ · NCCl and SbCl₅ · NCCN · SbCl₅ were characterized by X‐ray structural analysis. NBO analyses were performed on the crystallographic data.     

含磺基苯甲酸及联吡啶钌配合物的合成、结构和催化苯甲硫醚氧化研究

利用水热方法合成了一个三联吡啶钌磺基苯甲酸配合物,[Ru(2,2′-bipy)3](3-Hsb)(3-sb).5H2O(1)(2,2′-bipy为2,2′-联吡啶;3-sb2-为3-磺基苯甲酸根离子),对配合物进行了元素分析、红外、紫外、荧光和差热热重表征,解析了配合物的晶体结构。晶体结构解析表明:配合物1是阴离子-阳离子型化合物,阴离子与水分子形成三维有孔洞的氢键网络,阳离子占据这些孔洞。电化学性质测试表明:氧化还原是一个单电子可逆的过程,对应的可逆对为Ru(Ⅳ)/Ru(Ⅲ),E1/2=1.350 V。室温苯甲硫醚氧化催化实验表明:钌配合物与酸结合具有较高的催化活性与亚砜选择性。     

Synthesis,characterization, and crosslinking of novel stars comprising eight poly(isobutylene‐azeotropic‐styrene) copolymer arms with allyl or hydroxyl termini. I. Living azeotropic copolymerization of isobutylene and styrene

The overall objective of this research is the creation of novel star polymers consisting of well‐defined stable cores out of which radiate multiple poly(isobutylene‐co‐styrene) [P(IB‐co‐St)] arms whose glass‐transition temperature (T_g) can be controlled over a wide range (?73 to +100 °C) and whose arm termini are fitted with multipurpose (e.g., crosslinkable) functionalities. The first article of this series relates the synthesis and characterization of azeotropic IB/St copolymers [P(IB‐aze‐St)], which are to be subsequently used as end‐functional arms of the target stars. The P(IB‐aze‐St)s are models for statistical IB/St copolymers. The azeotropic composition is 21/79 (mol/mol) IB/St, and NMR, Fourier transform infrared, and gel permeation chromatography techniques demonstrate copolymer compositional homogeneity over the 12–96% conversion range. Conditions were developed for living azeotropic IB/St copolymerization. The livingness of the azeotropic copolymerization was proven by kinetic investigations. P(IB‐aze‐St)s with number‐average molecular weights of up to 24,000 g/mol and polydispersity indices (weight‐average molecular weight/number‐average molecular weight) less than 1.5 were prepared. The copolymerization reactivity ratios were determined: r_IB = 3.41 ± 0.23 and r_St = 1.40 ± 0.26. The effect of the P(IB‐aze‐St) molecular weight on T_g was studied by DSC. T_g increases linearly with the number‐average molecular weight and reaches a plateau at 62 °C at 24,000 g/mol. The heat stability of P(IB‐aze‐St) was investigated by thermogravimetric analysis, and a 5% weight loss was found at 250 °C in air. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1515–1524, 2001     

Catalytic behavior of a polynuclear Mg-Mo complex and nitrogenase active site (FeMoco) isolated from the enzyme in reactions with C2H2, N2, and CO: A comparative study

In order to identify common and distinctive features in the catalytic behavior of natural and artificial nitrogen-fixation clusters, the kinetics of the catalytic reduction of C₂H₂ in the presence of Mg-Mo-cluster (1) was investigated and compared with the kinetics of acetylene reduction catalyzed by the cluster FeMoco (2) isolated from the enzyme nitrogenase we studied previously. The reactions were conducted in the presence of Zn/Hg and Eu/Hg as reducing agents and PhSH and C₆F₅SH as proton donors, i.e., under the same conditions as had been used in the case of 2. Both polynuclear Mg-Mo-complex and the europium amalgam-reduced FeMoco have multiple interdependent binding sites for substrates and/or inhibitors. Carbon monoxide inhibits the acetylene reduction much less efficiently in systems with cluster 1 than in systems with cluster 2, although the type of inhibition is mixed in both systems: CO binds to multiple sites of the cluster and affects both C₂H₂ complexation to the reduced cluster and decomposition of the catalyst-substrate complex to give the products. Unlike isolated FeMoco, the Mg-Mo-cluster efficiently catalyzes the reduction of molecular nitrogen. The reaction is greatly inhibited by acetylene, while no inhibiting effect of N₂ is observed in acetylene reduction, as was found earlier for a system with the natural cluster as the catalyst. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 766–774, May, 2006.     

二苯乙醇酸铜配合物的合成、晶体结构、电化学和荧光性质

以二苯乙醇酸为配体合成了1个新的化合物[Cu(2,2′-bipy)(BAA)][Cu(2,2′-bipy)(BAA)(H2O)]2.(H2O)3(BAA=二苯乙醇酸阴离子,2,2′-bipy=2,2′-联吡啶)。该化合物晶体属三斜晶系,空间群P1,晶胞参数:a=1.121 7(5)nm,b=1.360 2(6)nm,c=2.335 2(10)nm,α=99.260(6)°,β=101.223(8)°,γ=94.805(8)°,V=3.425(3)nm3,Dc=1.385 g.cm-3,Z=6,μ(Mo Kα)=0.992 mm-1,F(000)=1 474,最终偏离因子R1=0.0561,wR2=0.1128。在标题化合物的不对称单元中有3个单核铜(Ⅱ)配合物,且3个中心铜(Ⅱ)离子的配位数不完全相同,如Cu(1)离子的配位数是4,而Cu(2)和Cu(3)离子的配位数都是5。本文还测定了标题化合物的电化学性能和荧光性能,结果表明:在电化学过程中配合物的电子转移是准可逆的,电子转移数为2个;配合物在478 nm的光激发下可发射荧光。