Capturing aqueous [F]-fluoride with an arylboronic ester for PET: Synthesis and aqueous stability of a fluorescent [F]-labeled aryltrifluoroborate

The aqueous stability of aryltrifluoroborates is of importance to their use in transition metal mediated coupling reactions as well as their potential use in [¹⁸F]-labeled aryltrifluoroborate PET imaging agents. Nevertheless, few studies have fully characterized the solvolysis of fluoride from an aryltrifluoroborate in water. Using [¹⁹F] NMR, fluorescence and [¹⁸F]-labeling techniques, we disclose the composition of an aryltrifluoroborate of exceptional kinetic stability with respect to solvolytic defluoridation. This work not only highlights the potential of using [¹⁸F]-labeled aryltrifluoroborates for PET tracers, but provides a chemical platform and a general approach for evaluating the stability of other aryltrifluoroborates.     

甲烷二氧化碳转化制备富含一氧化碳合成气

研究了甲烷二氧化碳转化反应的热力学特性,计算了反应平衡常数及平衡组成,分析和确定了抑制积碳的生成条件,采用固定床流动和脉冲反应装置研究了Ni/Al_2O_3催化剂对甲烷二氧化碳转化的催化性能。     

Synthesis and characterization of a novel series of pyrimidinylthiaalkoxycalix[4]arenes

A novel series of pyrimidinylthiaalkoxycalix[4]arenes with the reaction between 4,6-dimethylpyrimidine-2-thiol and thedifferent dibromides calix[4]aryl groups have been synthesized and structurally characterized by IR,1H NMR and MS.From theiranalysis data,it was found that compounds 8,9,11 adopted a cone conformation,while compound 10 existed as a mixture ofconformations.     

5，14－二氢－6，8，15，17－四甲基二苯并［b，i］［1，4，8，11］四氮杂［14］轮烯金属配合物的合成和反应性研究

合成了二苯并四氮杂［１４］轮烯金属配合物ＴＭＴＡＡＮｉ（Ⅱ），ＴＭＴＡＡＣｕ（Ⅱ）和ＴＭＴＡＡＶ＝Ｏ，通过ＴＭＴＡＡＭ（Ⅱ）分子中金属离子Ｍ（Ⅱ）对位碳原子上发生酰化反应，获得了十个酰化产物，用元素分析，ＩＲ，ＵＶ，１￣ＨＮＭＲ，（１９）￣ＦＮＭＲ和ＥＰＲ等进行了表征。酰化反应的发生说明了这类金属配合物具有类芳香性，并为改善这类大环金属配合物的光－电性能提供了良好的途径。     

杯[4]芳烃衍生物的合成和构象研究

以对取代酚亚甲基桥三聚体和２，６－二溴甲基对取代酚为原料，在ＴｉＣｌ４催化下环化得到６种新的含不同取代基［Ｃｌ，Ｂｒ，ＣＨ３，Ｃ（ＣＨ３）３］的杯［４］芳烃衍生物，核磁共振谱研究表明：它们在溶液中的优势构象为锥形构象。     

碳前驱体CH3ArCH2NH2热解反应的热力学和动力学DFT研究

在实验研究基础上 ,通过量子化学理论计算对碳前驱体 CH3 Ar CH2 NH2 的热裂解机理作了进一步的研究 .利用 Gaussian98程序包中 AM1方法及 DFT UB3 LYP/3 -2 1 G*方法 ,对化合物 5种可能热裂解路径的热力学和动力学计算结果表明 ,CH3 Ar CH2 NH2 热裂解的主反应路径为生成自由基 CH3 Ar CH2 ·和 NH2 · ,其主反应路径 AM1计算的活化能 Ea=2 3 0 .78k J/mol,DFT计算的活化能 Ea=3 2 1 .1 8k J/mol;比较键焓计算的数据与相应的实验数据 ,发现 DFT计算结果与实验结果吻合得较好 ;通过分析优化的反应物及产物自由基的部分结构参数 ,了解了理论支持主反应的原因 ;计算的产物自由基的空间构型表明主反应路径生成的产物自由基相互间若进行稠环缩合反应 ,将获得分子平面取向性很好的稠环芳烃产物     

Synthesis and Crystal Structure of a Novel Calix [8] arene Ester Derivative

The synthesis and crystal structure of a novel calix[8] arene ester are reported herein. The calix [8] arene ester derivative has been characterized by IR,NMR and X-ray crystal analysis. The X-ray structure analysis revealed that the 8 phenolic hydroxy groups of the calix [8] arene have been substituted by 4 diethyl dibromomalonate molecules with each two adjacent hydroxy oxygen atoms attached to a bridge diethyl malonate.     

Synthesis,Crystal Structure and Properties of Rubidium Dihydrogentricyanomelaminate Semihydrate Rb[H2C6N9] · 1/2 H2O

Rubidium dihydrogentricyanomelaminate semihydrate Rb[H₂C₆N₉] · ¹/₂ H₂O was obtained as colorless rod‐like single crystals from a solution of Rb₃[C₆N₉] · H₂O and 0.1 M HCl after water evaporation at room temperature. According to the X‐ray single‐crystal structure determination (Rb[H₂C₆N₉] · ¹/₂ H₂O: C2/c (no. 15), a = 2007.4(3) pm, b = 512.2(1) pm, c = 2168.0(4) pm, β = 111.66(2)°, Z = 8, R1 = 0.059, 2391 independent reflections, 159 parameters) Rb⁺ and cyclic planar [H₂C₆N₉]^— ions as well as hydrate water molecules occur in the crystal. Rb[H₂C₆N₉] · ¹/₂ H₂O was investigated by FTIR and Raman spectroscopy, TG measurements and temperature‐dependent X‐ray powder diffraction. According to the thermoanalytic investigations, dehydration of Rb[H₂C₆N₉] · ¹/₂ H₂O starts above 60 °C and is finished below 250 °C.     

Synthesis, crystal structures and the preliminary evaluation of the new dibenzotetraaza[14]annulene-based DNA/RNA binding agents

A series of water-soluble dicationic dibenzotetraaza[14]annulenes have been prepared in order to examine their interactions with nucleic acids. Pendant water-solubilizing N-pyridinium, 4,4′-bipyridinium and N-methyl pyridinium moieties have been attached to the central core via linkers generated by direct N-alkylations and ester creating couplings, respectively. The crystal structures of derivatives equipped with 3-(N-pyridinium-1-yl)propyl and 3-(4,4′-bipyridinium-1-yl)propyl substituents have been determined. Interactions with ct-DNA have been studied and evidenced by means of spectrophotometric titrations with Scatchard analysis and thermal denaturation experiments.     

Synthesis,Structure, and Decomposition of (NH4)2[Mo6Cl14] · H2O

(NH₄)₂[Mo₆Cl₁₄] · H₂O ( 1 ) was prepared from reactions of MoCl₂ in ethanol with aqueous NH₄Cl solution. It crystallizes in the monoclinic space group I2/a (no. 15), Z = 4 with a = 912.3(1), b = 1491.2(2), c = 1724.8(2) pm, β = 92.25(1)°; R1 = 0.023 (based on F values) and wR2 = 0.059 (based on F² values), for all measured X‐ray reflections. The structure of the cluster anion can be given as [(Mo₆Cl)Cl]^2– (i = inner, a = outer ligands). Thermal stability studies show that 1 loses crystal water followed by the loss of NH₄Cl above 350 °C to yield MoCl₂. The water‐free compound (NH₄)₂[Mo₆Cl₁₄] ( 2 ) was synthesized by solid state reaction of MoCl₂ and NH₄Cl in a sealed quartz ampoule at 270 °C. No single‐crystals could be obtained. Decompositions of 1 and 2 under nitrogen and argon exhibited the loss of NH₄Cl at about 350 °C. Decomposition under NH₃ resulted in the formation of MoN and Mo₂N at 540 °C and 720 °C, respectively.     

Synthesis of a Calix[4]arene Containing 'Hard' and 'Soft' Metal Ion Binding Sites

Co-receptor 1,3-calix[4]-di(aza-benzo)crown-crown-6 (1-H) designed with one calix[4]arene in a 1,3-alternate conformation and hard and soft metal ion binding sites has been prepared according to three pathways (A-C). Pathway B, consisting of two different 1 + 1 condensations with ditosylate derivatives, was shown to be the most efficient.     

二羟基二羟乙氧基杯[4]芳烃的合成与性质研究

通过杯[4]芳烃与碘乙醇的反应,制得了25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃,经IR,UV,1HNMR,13CNMR和MS等分析证实了产物的结构.用荧光光谱法研究了产物与稀土(Ⅲ)硝酸盐在乙腈溶液中的配位作用,并根据扩展的Hilderbrand-Benesi公式计算了配合物的稳定常数和配位反应的Gibbs自由能变化,结果发现,25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃与稀土(Ⅲ)硝酸盐在乙腈溶液中具有较强的配位能力.     

Synthesis and antimicrobial activities of novel quinazolin-4(3H)-one derivatives containing a 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole moiety

A series of novel quinazolin-4(3H)-one derivatives (6a–6y) containing a 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole moiety were designed and synthesized, and their structures were fully characterized by ¹H NMR, ¹³C NMR, HRMS and IR spectra. Among them, the structure of compound 6u was unambiguously confirmed via single crystal X-ray diffraction analysis. The obtained bioassay results showed that compounds 6h, 6k, 6l and 6y had the EC₅₀ (half-maximal effective concentration) values of 34.8, 28.2, 41.5 and 42.5 μg/mL against the phytopathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo), respectively, which were significantly better than commercial bactericide Bismerthiazol (EC₅₀ = 95.8 μg/mL). Additionally, compounds 6a and 6b exhibited the strong inhibition activity against the pathogen Xanthomonas axonopodis pv. citri (Xac).     

Synthesis and Crystal Structure of a Complex Bimetallic Salt [Ni(trans_[14]diene)] [Ni (mnt)_2]

1INTRoDUCTIONMacrocycliccoordinationcomPOundshavebeenwidelyinvestigatedinthepastdecadesbecauseoftheirrelationshiptocomplexesofbiologicalsignificancesuchasthePorphyrinsandcorrins(lJ.Structuresofmanymacrocycliccompoundshavebeenre-ported,especiallythecompoundscontainingN4macrocyclicligands"'.However,toourknowledge,onlyafewcrystalstructuresofcomplexbimetallicsaltscontainingmacrocyclicligandshavebeendeterminedbyX-raydiffractionmethod.Inthispa-per,werePortthesynthesisandstructureofthetit1ecom…     

Metal free Lewis acid promoted one-pot synthesis of 14-aryl-14H dibenzo [a,j] xanthenes and their simple biological evolution

A green, competent one-pot synthesis of 14-aryl 14H-dibenzo [a,j] xanthene and its bio-computational studies are reported. Target compounds are prepared by the condensation of 2-naphthol with benzaldehyde and its substituents using metal free benzyltrimethylammonium tribromide (BTMA-Br₃) catalyst under solvent free thermal and microwave conditions. This technique has more advantages such as high yield, a clean procedure, low reaction time, simple workup and mild Lewis organo acid catalyst.     

二苯并四氮杂轮烯金属配合物及其亲电取代反应性能

本文用量子化学半经验方法和从头算研究二苯并四氮杂[14]轮烯离子及其金属配合物，讨论了轮烯配合物的活性位置。^1HNMR谱表明Lunxi-Ni配合物中金属离子对位C7、C16上的H原子被取代，与理论计算结果一致。     

Synthesis, reactivity and structural characterization of ytterbium complexes bearing a tridentate [O,N,N] Schiff base ligand

The synthesis, characterization and reactivity of ytterbium monochloride supported by tridentate Schiff base ligands are described. The metathesis reaction of anhydrous YbCl₃ with 1 equivalent of the sodium salt of a Schiff base, [{LNa(THF)}₂] (1) [LH = 3,5-Bu^t₂-2-(OH)-C₆H₂CHN-8-C₉H₆N], gave the ytterbium Schiff base monochloride complex L₂YbCl (2). Complex 2 reacted with NaOAr (OAr = OC₆H₃Bu^t-2-Me-4) in a 1:1 molar ratio to form the desired aryloxo derivative L₂Yb(OAr) (3). Complex 3 can also be prepared by the one-pot reaction of the Schiff base HL, n-BuLi, YbCl₃ and NaOAr in a 2:2:1:1 molar ratio. However, an unprecedented ytterbium aryloxide LL′Yb(OAr) (4) (L′ = 3,5-Bu^t₂-2-(O)C₆H₂CH(C₄H₉)-NH-8-C₉H₆N) can be isolated in low yield as a byproduct in the later case. Reaction of complex 2 with 1 equivalent of (CH₂CH-CH₂)MgBr in THF afforded the unexpected complex [Mg(H₂N-8-C₉H₆N)Cl(THF)₃]Br (5). Complexes 2-5 were fully characterized by elemental analysis and X-ray diffraction.     

Synthesis and bioactivity of a novel series of 3, 6-disubstituted 1, 2, 4-triazolo [3, 4-b]-1, 3, 4-thiadiazoles

<正>A novel series of 3,6-disubstituted 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles were synthesized by the condensation of 4-amino-5- [2-(4-chlorophenoxymethylbenzimidazole)-1-methylene]-3-mercapto-1,2,4-triazole with various(un)substituted aromatic acids in the presence of phosphorous oxychloride.These compounds were investigated for their inhibitory activity to E.coli methionine aminopeptidase(EcMetAP1).Some of the tested compounds showed significant inhibitory activity.     

单分子磁体[Mn4(CF3COO)4(hmp)6]的合成、晶体结构及磁学性质

以[Mn12O12(CF3COO)16(H2O)4]·2CF3COOH·4H2O和2-羟甲基吡啶(hmpH)为起始物, 在四氢呋喃溶液中合成了一种新的四核锰配合物[Mn4(CF3COO)4(hmp)6]. X射线单晶衍射结果表明, 该配合物属于单斜晶系, P21/c空间群, 晶胞参数a=1.3663(3) nm, b=1.4705(3) nm, c=1.4734(3) nm, β=98.51(3) °, V=2.9276 nm3, Z=2. 配合物中有两个CF3COO-基团与七配位Mn2中心相连, 其中一个为单齿配体, 另一个是双齿配体. 直流磁化率研究结果表明, 该配合物具有较高的自旋基态, 而交流磁化率依赖于外场频率变化极值的出现表明该配合物是一种单分子磁体.