新型桥连双卟啉化合物的合成及结构表征

通过将4,4′-二羧基-2,2′-联吡啶、2,6-二溴甲基吡啶、2,6-二羟甲基吡啶和1,8-二氨基萘分别与5-(4-羟基苯基)-10,15,20-三苯基卟啉(1a)、5-(4-甲酰苯基)-10,15,20-三苯基卟啉(1b)和5-[4-(4′-溴代丁氧基)苯基]-10,15,20-三苯基卟啉(1c)反应,合成了3类新型的双卟啉化合物2a-2e,经IR,¹HNMR,MS,UV-Vis光谱及元素分析对中间体和目标化合物的结构进行了表征.     

新型燃速催化剂—烷基二茂铁桥联双聚分子的电化学研究

液态烷基二茂铁桥联双聚分子是一类新型燃速催化剂,它不仅具有催化活性高的优良特性,而且挥发性及迁移性均有改善,适宜用于火箭燃料复合固体推进剂。本文合成9种含不同取代基的双核二茂铁化合物,其中6种为首次合成。该9种化合物的通式为:其结构通式、各化合物的编号、英文名缩写及所含取代基和桥联基表示如下:     

Palladium catalyzed oxidation of monoterpenes: NMR study of palladium(II)-monoterpene interactions

Reactions of the monoterpenes β-pinene, limonene and myrcene with Pd(II) complexes in acetic acid solutions were studied by ¹H NMR spectroscopy. Various π-allyl palladium complexes were detected in situ and their interaction with CuCl₂ has been investigated. The results clarify the mechanism of allylic oxidation of these substrates mediated by Pd(II)/Cu(II)-based catalytic systems. Originally introduced to regenerate reduced palladium species, CuCl₂ has been shown to play an important role in the formation and/or decomposition of key reaction intermediates - π-allyl palladium complexes. β-Pinene and myrcene readily react with Pd(OAc)₂ giving corresponding π-allyls, with two complexes acyclic and cyclic being formed from myrcene. On the other hand, the formation of π-allyl complexes from limonene occurs at a significant rate only in the presence of CuCl₂. NMR observations, including selective paramagnetic enhancement of spin-lattice relaxation, indicate that π-allyl palladium intermediates specifically interact with Cu(II) ions in the reaction solutions. Such interaction probably involves Cu(II) bonding to Pd(II) via bridging ligands, and seems to be responsible for the accelerative effect of CuCl₂ in the palladium catalyzed oxidation of the monoterpenes. Indeed, most of these reactions do not occur at all in the absence of CuCl₂.     

氰酸根桥联双核铜配合物磁构效关系的密度泛函研究

在密度泛函理论的框架下,采用对称性破损态方法,以{Cu2(C2H4N2)2(N, N-μ-NCO)2}2+为模型化合物,研究氰酸根EO方式桥联双核铜配合物的磁构效关系,进一步证实了通过CuNCu间的三中心d-p-dσ反键的超交换作用与磁偶合构效关系的本质联系. 计算了氰酸根桥联配合物磁交换偶合常数J与桥联角θ的关系,并与叠氮酸桥联配合物进行了比较.     

Noncovalently-Bound Cyclodextrin Dimers and Related Compounds. (Review)

In the review noncovalently-bound cyclodextrin (CD) dimers, i. e., CD host-guest 2:1 complexes as well as CD self-assembled inclusion oligomers, are briefly characterized, showing methods of their investigations; the properties and possible applications of these species are also described. __________ Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1603–1624, November, 2005.     

Some Arylidene-2-Pyridylhydrazone Derivatives as Reagents for Spectrophotometric Determination of Palladium (II)

Abstract

A method for spectrophotometric determination of palladium by complexation with Arylidene-2-pyridylhydrazone derivatives in 50% (V/V) ethanolic solution are described-Pd(II) forms a 1:1 complex with the reagents. Beer's law is obeyed over the range 0.2-6.5 μg ml^?1. The effect of pH, effect of excess reagent, stability of complexes as well as the tolerance amount of many metal ions have been reported. The method is applied, with fair accuracy, to the determination of pd(II) in synthetic solutions.     

Palladium(II) Complexes of 1-vinylimidazole

Two new co-ordination compounds of Pd^II with 1-vinylimidazole of the formulae [PdL₄]Cl₂·3H₂O and trans-[PdL₂Cl₂], where L is a 1-vinylimidazole molecule, have been obtained. The compounds were characterised by spectroscopic, molar conductivity, thermogravimetric and magnetochemical measurements. Single crystal X-ray structure analyses of the complexes were also carried out. The compounds are diamagnetic with square-planar coordinatination around the palladium(II) ions. Other physico-chemical properties of the both complexes are compatible with their structures.     

Palladium(II) and platinum(II) 2-(methoxycarbonyl)ethylselenolates: Synthesis, spectroscopy, structures and their conversion into metal selenide

A diselenide, (MeOOCCH₂CH₂Se)₂ (1) has been prepared by esterification of (HOOCCH₂CH₂Se)₂ in methanol. The reductive cleavage of Se-Se bond in 1 by NaBH₄ in methanol generates MeOOCCH₂CH₂SeNa. The latter in different stoichiometries reacts with [M₂Cl₂(μ-Cl)₂(PR₃)₂] to give a variety of products of compositions [M₂Cl₂(μ-SeCH₂CH₂COOMe)₂(PR₃)₂] (2); [M₂Cl₂(μ-Cl)(μ-SeCH₂CH₂COOMe)(PR₃)₂] (3); [Pd₂(SeCH₂CH₂COOMe)₂(μ-SeCH₂CH₂COOMe)₂(PR₃)₂] (4);[Pd₃Cl₂(μ-SeCH₂CH₂COOMe)₄(PR₃)₂] (5). Treatment of complexes 2 with [M₂Cl₂(μ-Cl)₂(PR₃)₂] affords complexes 3 in nearly quantitative yield. The formation of various products in these reactions is sensitive to stoichiometric ratio of reactants employed. This enables interconversion of various complexes by manipulating mole ratios of appropriate starting materials. A homoleptic palladium complex, [Pd(SeCH₂CH₂COOMe)₂]₆ (6) was isolated from a reaction between Na₂PdCl₄ and MeOOCCH₂CH₂SeNa. All these complexes have been characterized by elemental analysis, IR, UV-Vis and NMR (¹H, ¹³C, ³¹P, ⁷⁷Se, ¹⁹⁵Pt) spectroscopy. Structures of trans-[Pd₂Cl₂(μ-SeCH₂CH₂COOMe)₂(PPh₃)₂] (2d), [Pt₂Cl₂(μ-Cl)(μ-SeCH₂CH₂COOMe)(PⁿPr₃)₂] (3e), [Pd₃Cl₂(μ-SeCH₂CH₂COOMe)₄(PⁿPr₃)₂] (5) and [Pd(SeCH₂CH₂COOMe)₂]₆ (6) have been established unambiguously by X-ray crystallography. In these complexes, there are bridging selenolate ligands with their uncoordinated ester groups. Compound 6 has a centrosymmetric Pd₆Se₁₂ hexagon in which every two palladium atoms are bridged by selenolate ligands. Thermal behaviour of some complexes has been investigated. Pyrolysis of compound 2b in tributylphosphate at 195 °C gave Pd₁₇Se₁₅ nanoparticles which were characterized by XRD and EDAX.     

DNA Binding Studies and Cytotoxicity of Ethylenediamine 8‐Hydroxyquinolinato Palladium(II) Chloride

Interaction between ethylenediamine 8‐hydroxyquinolinato palladium(II) chloride and calf thymus DNA (CT‐DNA) in aqueous solution were studied by UV‐Visible absorption, fluorescence spectroscopic techniques and gel chromatography at temperatures of 300 K and 310 K. The complex bound strongly and intercalatively to the CT‐DNA. The results of the cytotoxicity assay of the Pd(II) complex on the leukemia cell line, K562 indicated lower cytotoxicity than cisplatin. The Pd(II) complex is considered an agent with potential antitumor activity. The calculation of several binding and thermodynamic parameters of the inclusion Pd(II) complex with CT‐DNA may provide deeper insights into the mechanism of action of these types of complexes with nucleic acids.     

New Palladium(II) Complexes with a Tridentate PNO Ligand

The synthesis of neutral and cationic palladium complexes containing the tridentate monoanionic ligand [2-(2-Ph₂PC₆H₄-CH=N)C₆H₄O]^? is described. Deprotonation of the Schiff base formed by condensation of 2-(diphenylphosphino)benzaldehyde with 2-aminophenol in the presence of the appropriate palladium precursor ([Pd(AcO)₂] or [PdCl₂(PhCN)₂]) form the corresponding neutral complexes [Pd{2-(2-Ph₂PC₆H₄-CH=N)C₆H₄O}(AcO)] (1) or [Pd{2-(2-Ph₂PC₆H₄-CH=N)C₆H₄O}(Cl)] (2) in good yield. The first reacts smoothly with thiols and activated phenols to give complexes of general formula [Pd{2-(2-Ph₂PC₆H₄-CH=N)C₆H₄O}(X)] (X = OC₆F₅ (3), SEt (4), S^tBu (5), SC₆H₅ (6), SC₆H₄-4Me (7), SC₆H₄-4NO₂ (8)). When the chloro complex is treated with silver perchlorate and tertiary phosphines (L) the cationic derivatives [Pd{2-(2-Ph₂PC₆H₄-CH=N)C₆H₄O}(L)][ClO₄] (L = PPh₃ (9), PMePh₂ (10), PMe₂Ph (11), PEt₃ (12)) were obtained. The new complexes were characterized by partial elemental analyses and spectroscopic methods (IR, ¹H, ¹⁹F and ³¹P NMR).     

Palladium(II)-catalyzed addition of arylboronic acid to nitriles

The addition of arylboronic acid to nitriles catalyzed by palladium(II) species in the presence of bipyridine as the ligand was developed. The use of bipyridine is crucial for changing the properties of arylpalladium species from more electrophilic to more nucleophilic making the reaction possible.     

Tripropylarsane Complexes of Palladium(II) and Platinum(II) — Syntheses,Spectroscopy, and Structures

Several palladium(II) and platinum(II) complexes of tripropylarsanes (AsR₃; R = Pr, iPr) with the formulae, [MCl₂(AsR₃)₂], [M₂Cl₂(μ‐Cl)₂(AsR₃)₂], [Pd₂Me₂(μ‐Cl)₂(AsR₃)₂], [Pd₂X₂(μ‐Pz)₂(AsR₃)₂] (X = Cl or Me, Pz = pyrazolate), [Pd₂Cl₂(μ‐Y)₂(AsR₃)₂] (Y = OAc or SPh), [MCl(S₂CNEt₂)(AsR₃)] and [PdCp(Cl)(AsiPr₃)] (M = Pd or Pt) have been prepared. All the complexes have been characterised by elemental analyses, IR and ¹H NMR spectroscopy. The stereochemistry of the complexes has been deduced from the spectroscopic data. The structures of [Pd₂Me₂(μ‐X)₂(AsiPr₃)₂] (X = Cl or Pz) have been established by single crystal X‐ray diffraction analyses. Both of the complexes have sym‐trans configuration. Strong trans influence of the methyl group is reflected on the Pd—X bond distances.     

Palladium(II)-catalyzed ring expansion of a 1-alkenyl cyclopentanol

7,7-Dimethyl-2-methylenenorbornan-1-ol, a strained bicyclic 1-alkenyl cyclopentanol, undergoes Wagner-Meerwein rearrangement to fenchone under treatment with a catalytic amount of PdCl₂(PPh₃)₂ in refluxing N-methylpyrrolidin-2-one. The described reaction constitutes the first example of the palladium(II)-catalyzed ring expansion of 1-alkenyl cyclopentanols to the corresponding cyclohexanones.     

Determination of Osmium(VIII) and Palladium(II) in Mixtures by Derivative Spectrophotometry

Abstract

A sensitive method for the simultaneous determination of osmium(VIII) and Palladium(II) (up to 15 μ9/ml of Os and 11 μ9/ml of Pd) in mixtures, by first and second derivative spectrophotometry, using allyl thiourea as reagent, is described.

A statistical analysis of the results is reported.     

Synthesis of Alkylene—linked Dimers of （—）—Huperzine A

Six alkylene-linked dimers of (-)-huperzineA(6) were prepared. All these dimers are less potent than (-)-Hup A in inhibition of AChE.     

Syntheses and Crystal Structures of New Palladium(II) and Platinum(IV) Trialkylsulfonium Compounds

The reactions of platinum(II) iodide with triethyl‐ or trimethylsulfonium iodide in acetonitrile solution lead to the formation of crystalline products (Et₃S)₂[PtI₆] ( 1 ) and [Me₃S]₂[PtI₆]·CH₃CN ( 2 ), respectively. The formation of Pt(IV) complexes may be explained either by disproportionation of PtI₂ or oxidation by oxygen. Palladium(II) iodide reacts with triethylsulfonium iodide to give the palladium(II) complex (Et₃S)₂[PdI₄] ( 3 ). The crystal structures of 1 – 3 were determined by single‐crystal X‐ray diffraction. In the crystal structures, the compounds 2 and 3 exhibit an extensive hydrogen‐bonding network.     

Palladium(II)-catalyzed isomerization-Claisen rearrangement of 2-alkoxy diallyl ethers

Diallyl ethers bearing an enol ether react in the presence of PdCl₂ as catalyst to give α-allyl α-alkoxy ketones by selective isomerization via formal 1,2-H migration at the more substituted allyl group, followed by Claisen rearrangement. This rearrangement is also promoted by AuCl₃ and IrCl₃, although the yields are lower with these catalysts.     

Determination of Trace Amounts of Palladium(II) by Solid-Phase Spectrophotometry

A simple and sensitive method for solid-phase spectrophotometric determination of palladium(II) at µgL^–1 level based on the reaction product of Pd²⁺ with disodium 1-nitroso-2-hydroxynaphthalene-3,6-disulphonate (Nitroso R salt) previously immobilized on Dowex 1×1 anion exchanger has been developed. The experimental factors (wavelength, pH, amount of resin, concentration of Pd²⁺ solution, volume of solution sample, equilibration time) were optimized. The advantages of this procedure as opposed to solution methods are discussed. The results obtained with synthetic solutions clearly indicate the suitability of the proposed method for real samples analysis.