固相萃取-液相色谱-串联质谱法同时测定尿液中9种多环芳烃代谢物

建立了固相萃取-液相色谱-串联质谱同时测定尿中2-羟基萘、1-羟基萘、2-羟基芴、3-羟基菲、1-羟基芘等9种多环芳烃代谢物的液相色谱-串联质谱测定方法。尿样中结合态的多环芳烃代谢物在β-葡萄糖苷酸酶-芳基硫酸酯酶缓冲液(pH 5.0)作用下,于37℃水浴中避光水解4 h后,以C18固相萃取小柱富集、净化,以甲醇洗脱,采用Waters Symmetry C18色谱柱,流动相为乙腈-0.2%氨水(72∶27,V/V)等度淋洗分离后进入质谱测定。在喷雾电压4 kV,毛细管温度300℃下,以3-羟基菲13C为内标,采用SRM模式负离子扫描方式测定,内标法定量。9种多环芳烃代谢物在尿中的线性范围为0.90～100μg/L;相关系数为0.9970～0.9990;回收率为79.0%～119.8%;相对标准偏差为4.3%～12.4%;检出限为0.04～0.90μg/L;结果表明,本方法可用于尿中9种多环芳烃代谢物的测定。     

Synthesis,DNA-binding,and photocleavage properties of Ru(II) complexes containing dppz-based ligand

A ligand ipdp (ipdp?=?indeno[1′,2′?:?5,6]pyrazino[2,3-i]dipyrido[3,2-a?:?2′,3′-c]phenazine-8-one) and its ruthenium complexes, [Ru(L)₂(ipdp)]²⁺ (L?=?bpy (2,2′-bipyridine), phen (1,10-phenanthroline)), have been synthesized and characterized by elemental analysis, electrospray mass spectra, and ¹H NMR. The interaction between the complexes and calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods and viscosity measurements. The results indicate that the complexes can bind to CT-DNA in an intercalative mode. In addition, both complexes promote the photocleavage of plasmid pBR322 DNA under irradiation. The mechanistic studies reveal that singlet oxygen ¹O₂ plays a significant role in DNA photocleavage.     

Syntheses,structural characteristics,and antimicrobial activities of new organotin(IV) 3-(4-bromophenyl)-2-ethylacrylates

New organotin(IV) carboxylates, [n-Bu₂SnL₂] (1), [Et₂SnL₂] (2), [Me₂SnL₂] (3), [n-Oct₂SnL₂] (4), [n-Bu₃SnL] _n (5), [Me₃SnL] _n (6), and [Ph₃SnL] _n (7), where L?=?3-(4-bromophenyl)-2-ethylacrylate, were synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Spectroscopic studies confirm coordination of L to the organotin moiety via COO group. Single-crystal X-ray analysis reveals bridging mode of coordination in 6. Packing diagram established a supramolecular cage-like structure for 6 due to Sn–O interactions (3.287?Å). Subsequent antimicrobial activities proved them to be active biologically.     

2,2′-Bipyridyl-acetylphenolato mixed ligand copper(II) complexes: syntheses,characterizations and catalytic activity in styrene epoxidation

Two copper(II) complexes, [Cu(bipy)(5-Br-2-hap)(ClO₄)]₂ (1) and [Cu(bipy)(2-hap)(ClO₄)] (2) (where bipy?=?2,2′-bipyridine, 5-Br-2-hap?=?5-bromo-2-hydroxyacetophenone, 2-hap?=?2-hydroxyacetophenone), were synthesized and characterized. The crystal structure of 1 was determined by single crystal X-ray diffraction while 2 was reported earlier. Structural characterization reveals that the presence of bromine in 5-Br-2-hap plays a structure-determining role in dimeric 1 in comparison with the mononuclear 2 where 2-hap was used. Studies of the catalytic potential toward styrene epoxidation in homogeneous system using H₂O₂ as oxidant reveal that 1 is more efficient than 2 with respect to epoxide selectivity.     

Two copper(II) metal–organic networks derived from bis-pyridyl-bis-amide ligands and aromatic polycarboxylates: a 2-D layered structure and a 4-connected trinodal 3-D topology

Two metal–organic coordination polymers, [Cu₃(4-bpcb)₂(1,2,4-btc)₂(H₂O)₂] (1) and [Cu₃(3-bpcb)₃(btec)_1.5] (2), have been synthesized from hydrothermal reaction of copper chloride with mixed ligands [4-bpcb?=?N,N′-bis(4-pyridinecarboxamide)-1,4-benzene, 3-bpcb?=?N,N′-bis(3-pyridinecarboxamide)-1,4-benzene, 1,2,4-H₃btc?=?1,2,4-benzenetricarboxylic acid, and H₄btec?=?1,2,4,5-benzenetetracarboxylic acid]. X-ray diffraction analysis reveals that 1 exhibits a 2-D layer structure and 2 possesses a three-dimensional (3-D) network. In 1 and 2, Cu^II ions are connected by bridging 1,2,4-btc or btec to form 2-D polymeric layers. Cu-1,2,4-btc layer does not propagate into a 3-D coordination framework in 1 due to 4-bpcb showing monodentate coordination (via ligation of only one pyridyl nitrogen). In 2, Cu-btec 2-D layers are further extended into a 3-D network with (6⁴.8²)₃ topology by 3-bpcb ligand in μ ₂-bridging coordination (via ligation of two pyridyl nitrogens). The different structures of the two complexes illustrate the influence of different polycarboxylates and N-donor positions of organic ligands on the formation of such coordination architectures. Moreover, the thermal properties and electrochemical properties of the copper complexes bulk-modified carbon paste electrodes have been studied.     

Synthesis and crystal structure of a triple-decker CuII3TlI2 complex: first example of a thallium(I) system in the imino-phenolate Schiff base ligand family

This report deals with the synthesis, characterization, and crystal structure of a heteropentanuclear Cu^II₃Tl^I₂ compound [(Cu^IIL)₃Tl^I₂](NO₃)₂ (1), where H₂L=N,N′-ethylenebis(3-ethoxysalicylaldimine). This compound crystallizes in the monoclinic crystal system within space group C2/c. Each of the two symmetry related thallium(I) centers is located between a terminal and a common, central [Cu^IIL] by forming bonds with four phenoxo and three ethoxy oxygens. The three [Cu^IIL] moieties are parallel and hence 1 is a triple-decker system. Neighboring triple-decker moieties are interlinked by π?π stacking interaction and weak hydrogen bonds to generate 3-D self-assembly in 1. Salient features in the composition and structure of the title compound are discussed; the title compound is the first example of a thallium(I) system in imino-phenolate Schiff base family.     

Syntheses,crystal structures,and magnetic properties of a series of Fe2Ln complexes

A family of phenoxo-bridged heterometallic Schiff base trinuclear complexes, [Fe₂LnL₂(C₃H₇COO)(H₂O)]·CH₃OH·CH₃CN·H₂O (Ln = Sm, 1; Gd, 2; Tb, 3; Dy, 4) is reported. Those complexes were afforded by “one-pot” reaction of a polydentate Schiff base ligand 2-hydroxy-3-methoxy-phenylsalicylaldimine (H₂L) with Fe(NO₃)₃·9H₂O, Ln(NO₃)₃·6H₂O and sodium butyrate (C₃H₇COONa) in a mixture of methanol and acetonitrile in the presence of triethylamine as a base. Single-crystal X-ray diffraction analysis reveals that the structures of the four complexes are isomorphic. In each complex, two anionic [FeL₂]^? units coordinate to the central lanthanide ion as a tetradentate ligand using its four phenoxo oxygens, forming a two-blade propeller-like molecular shape. Magnetic properties of 1–4 were investigated using variable temperature magnetic susceptibility, and weak ferromagnetic exchange between the Fe^III and Ln^III ions has been established for the Gd derivative. The Tb and Dy complexes show no evidence of slow relaxation behavior above 2.0 K.     

Synthesis and characterization of a thioether Schiff base ligand and its metal complexes and crystal structure determination of the nickel(II) complex

Reactions of 1,2-di(o-aminophenylthio)ethane with 3-ethoxy-2-hydroxybenzaldehyde yield the new hexadentate N₂S₂O₂ donor thioether Schiff base 1,2-bis(2-((2-(thio)phenylimino)methyl)-6-ethoxyphenol)ethane (H₂L). Ni(II), Zn(II), Cd(II), and Hg(II) complexes of this ligand were prepared. Of these complexes, [NiL]·2H₂O has been structurally characterized by X-ray crystallography. The coordination geometry around Ni(II) was described as octahedral. Zn(II), Cd(II), and Hg(II) complexes and the Schiff base ligand have been characterized by CHN analyses, molar conductivity, UV–vis, FT-IR, ¹H, and ¹³C NMR spectroscopy.     

Copper(I) bromide and chloride complexes with urotropine and triethylenediamine: synthesis,crystal structure,and Raman characterization*

Abstract

In the present study, the oxidative dissolution of metallic copper has been explored with the intention to prepare some new complexes with urotropine (hmta) and triethylenediamine (dabco) ligands. All the compounds synthesized were characterized by single-crystal X-ray diffraction and Raman spectroscopy. Reactions performed in a DMSO/CuCl₂?2H₂O mixture resulted in [(μ-Cl)₂Cu^I(hdabco⁺)Cu^I(μ-Cl)(κS-DMSO)]_n and [Cu^ICl(hmta)₂] complexes. Their isostructural bromide analogs [(μ-Br)₂Cu^I(hdabco⁺)Cu^I(μ-Br)(κS-DMSO)]_n and [Cu^IBr(hmta)₂] were prepared by the reaction of elemental copper with respective ligands in a DMSO/CBr₄ mixture. Early interrupted reaction of the copper wire with the DMSO/CBr₄/dabco solution resulted in an appearance of crystals of the [Cu^I₂Br₂(CO)₂(dabco)]_n carbonyl complex on the copper surface. It arises with the participation of in situ formed carbon monoxide. Despite the identical stoichiometry, the crystal structure of the [Cu₂Br₂(CO)₂(dabco)]_n complex is markedly different from that of a known [Cu₂Cl₂(CO)₂(dabco)]_n analog.     

Crystal structures and luminescent properties of a cadmium(II) metal-organic framework based on tri(4-pyridylphenyl)amine

Abstract

A luminescent cadmium(II) metal-organic framework, [Cd(tppa)₂ (bpdc)₂]_n (1) (tppa?=?tri(4-pyridylphenyl)amine, bpdc =4,4′-biphenyldicarboxylic acid), has been solvothermally synthesized by using Cd(NO₃)₂·4H₂O and a mixture of tppa and bpdc. Single crystal X-ray analysis reveals that 1 crystallizes in the orthorhombic system and Pbcn space group. Its overall structure is a twofold interpenetrated framework, and it shows a porosity of 31.8% based on a calculation by PLATON and a 4-c type topological network with the point symbol of {6^5.8}. In addition, 1 may be exploited as WLED due to its ability to give off yellow light under ultraviolet excitation.