Oligonucleotide Analogues with Integrated Bases and Backbone. Part 14

The self‐complementary tetrameric propargyl triols 8, 14, 18 , and 21 were synthesized to investigate the duplex formation of self‐complementary, ethynylene‐linked UUAA, AAUU, UAUA, and AUAU analogues with integrated bases and backbone (ONIBs). The linear synthesis is based on repetitive Sonogashira couplings and C‐desilylations (34–72% yield), starting from the monomeric propargyl alcohols 9 and 15 and the iodinated nucleosides 3, 7, 11 , and 13 . Strongly persistent intramolecular H‐bonds from the propargylic OH groups to N(3) of the adenosine units prevent the gg‐type orientation of the ethynyl groups at C(5′). As such, an orientation is required for the formation of cyclic duplexes, this H‐bond prevents the formation of duplexes connected by all four base pairs. However, the central units of the UAUA and AAUU analogues 18 and 14 associate in CDCl₃/(D₆)DMSO 10 : 1 to form a cyclic duplex characterized by reverse Hoogsteen base pairing. The UUAA tetramer 8 forms a cyclic UU homoduplex, while the AUAU tetramer 21 forms only linear associates. Duplex formation of the O‐silylated UUAA and AAUU tetramers is no longer prevented. The self‐complementary UUAA tetramer 22 forms Watson–Crick‐ and Hoogsteen‐type base‐paired cyclic duplexes more readily than the sequence‐isomeric AAUU tetramer 23 , further illustrating the sequence selectivity of duplex formation.     

卟啉作为信号传递介质的紫外可见光谱研究

合成了6种氨基酸水杨醛席夫碱(Sal-AA)：Sal-Gly(甘氨酸)、Sal-Phe(苯丙氨酸)、Sal-Arg(精氨酸)、Sal-Tyr(酪氨酸)、Sal-Met(甲硫氨酸)、Sal-Glu(谷氨酸)及其金属铜配合物。并分别在2种不同介质(三氯甲烷和甲醇)中，与四苯基卟啉TPP进行反应，研究了其紫外可见光谱性质，讨论了卟啉作为人工信号转导体系的传递介质，与氨基酸水杨醛席夫碱铜配合物的反应中，实现信号分子铜离子进一步传递的可能性以及溶剂对该信号传递的影响。结果表明，在三氯甲烷为溶剂时，除了Sal-Met的铜配合物之外，其余均能被TPP夺取而形成Metal TPP。而在以甲醇为溶剂时，只有Sal-Gly的铜配合物能被TPP所夺取。     

Syntheses,structures and electrochemical properties of ruthenium(II/III) complexes with tetradentate Schiff base ligands

Three unsymmetrical tetradentate Schiff base ligands, H₂salipn, H₂salipn-Br₄ and H₂salipn-Cl₂, have been synthesized from the typical condensation reactions of treating 1,2-diaminopropane with salicylaldehyde, 3,5-dibromosalicylaldehyde and 5-chlorosalicylaldehyde, respectively. Treatment of [RuCl₂(PPh₃)₃] with one equivalent of H₂salipn or H₂salipn-Br₄ in the presence of triethylamine in tetrahydrofuran (THF) afforded the corresponding ruthenium(III) complexes [Ru^IIICl(PPh₃)(salipn)] (1) and [Ru^IIICl(PPh₃)(salipn-Br₄)] (2). Interaction of [RuHCl(CO)(PPh₃)₃] with one equivalent of H₂salipn-Cl₂ or H₂salipn-Br₄ under the same conditions led to isolation of ruthenium(II) complexes [Ru^II(CO)(PPh₃)(salalipn-Cl₂)] (3) and [Ru^II(CO)(PPh₃)(salalipn-Br₄)] (4), respectively, in which one of the imine bonds was nucleophilically attacked by hydride to result in the formation of a mixed imine-amine ligand. The molecular structures of 1?1.5CH₂Cl₂, 2, 3?0.5CH₂Cl₂ and 4 have been determined by single-crystal X-ray crystallography. The electrochemical properties of 1–4 were also investigated. Their cyclic voltammograms displayed quasi-reversible Ru(IV)/Ru(III) and Ru(III)/Ru(II) couples with E^o ranging from 0.67 to 1.05 V and 0.74 to 0.80 V vs. Ag/AgCl (0.1 M), respectively.     

钴希夫碱配合物及其分子氧加合物的合成与表征

以β-萘酚醛与一系列二胺缩合为配体,合成了钴的配合物。通过测定配合物在各种溶剂中吸收的氧气,得到了配合物与分子氧的摩尔比。并从各种溶剂中分离出了一系列2:1和1:1(Co/O_2)的分子氧加合物。对这些配合物和分子氧加合物进行了元素分析,红外、紫外一可见光谱和磁化率的表征,并研究了性质与结构的关系。     

Base-labile tert-butoxycarbonyl (Boc) group on phenols

Phenols are deprotected with weak bases from their tert-butoxycarbonyl (Boc) derivatives. Boc deprotection with bases can avoid side reactions during the deprotection with acids. We note the lability of the Boc to bases and are able to utilize it as a new cleavage condition for synthetic studies.     

微量吸附量热技术在NH2-SBA-15合成中的应用

采用共价接枝法, 以氨丙基-三乙氧基硅烷为氨源, 制备了一系列的NH2-SBA-15催化剂, 通过微量吸附量热技术定量地分析了该催化剂表面碱性中心的强度、数量和分布状态. 实验结果表明, SBA-15在 550 ℃焙烧6 h, 氨基硅源与SBA-15质量比为1.5, 是合成NH2-SBA-15催化剂最适宜的条件. 运用微量吸附量热技术实现了对NH2-SBA-15催化剂合成条件的优化.     

Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(Ⅱ) Dimer Containing Taurine Schiff Base [Zn_2(C_8H_9N_2O_3S)_2·(N_3)_2·(H_2O)_2]_2·_2H_2O

1 INTRODUCTION The investigation of Shiff base complexes con- taining sulfur and complexes of amino acid Schiff bases[1, 2] has recently aroused considerable interest due to their antiviral, anticancer and antibacterial activities. Taurine, known as 2-aminosulfonic acid, is indispensable to human beings and plays an im- portant role in physiological functions. In this con- tribution, we present the synthesis and crystal struc- ture of a new binuclear Zn(II) dimmer with a tri- dentate Sc…     

一维链状配位聚合物[Cu3(TFSSB)2·(H2O)4·4H2O]n的合成和晶体结构

The title complex [Cu₃(TFSSB)₂·(H₂O)₄·4H₂O]_n (TFSSB=taurine 3-formylsalicylic schiff base) was synthesized by TFSSB and copper(Ⅱ) acetate monohydrate in ethanol solution and the crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic system, space group P2₁ / n，with cell parameters: a=0.927 9(6) nm, b=1.173 0(2) nm, c=1.471(2) nm, β=106.96(2)°, and V=1.531(2) nm³, Z=2, D_c=1.890 g·cm^-3, μ=2.291 mm^-1, F(000)=882, R₁=0.025 9, wR₂=0.065 9. The Cu1 is five-coordinate, the Cu2 is four-coordinate. CCDC: 253298.     

穴状Schiff碱配合物［Gd(NO3)·L］(NO3)2的晶体结构

A new mononuclear gadolinium complex ［Gd(NO₃)·L］(NO₃)₂ of Schiff base cryptand was obtained by condensation of tris (2-aminoethyl)amine with 2,6-diformyl phenol in template procedure. The complex was characterized by elemental analysis, IR, and x-ray single crystal diffraction analysis. Gadolinium is nine-coordinate in trigonal tricapped prism with five oxygen atoms from three phenols and a bidentate nitrate group, and four nitrogen atoms from three imino C=N bonds and a tertiary amine in the cryptand. The complex crystallized in triclinic system space group P1, a=1.0839(2) nm, b=1.2600(4) nm, c=1.7595(4) nm, α=82.09(2)°, β=89.22(2)°, γ=84.06(2)°， V=2.367(2) nm³, Z=2.     

高分子希夫碱金属配合物活性中心对催化活化分子氧性能的影响

以交联聚苯乙烯担载酪氨酸希夫碱为配体,制备了其锰、钴、铜高分子金属配合物,分别以环己烯、异丙苯和乙苯为底物,氧气为氧源,研究了温和条件下不同金属中心活化分子氧能力,发现高分子担载铜金属配合物的催化活化分子氧能力最强,对反应机理进行了探讨.