Synthesis and characterization of cationic astatine compounds with sulphur-containing ligands stable in aqueous solutions

The formation of cationic astatine compounds with thiourea, thiourea derivatives and some N-acylthioureas was investigated in aqueous solutions. The ion mobilities in free electrolytes were determined for the detection of carrier-free astatine compounds and their characterization. Informations about the stability of this group of compounds could be given after investigations in the presence of halogenide and pseudo halogenide ions /Cl^–, Br^–, I^–, SCN^–/. First results on the reaction of At//⁺ with thiourea derivatives and N-acylthioureas in acid and neutral solutions are reported. The cationic astatine compound formation with representatives of this group is shown.     

Synthesis and first characterization of cationic At/I/-compounds with selenium-containing neutral ligands

The formation of cationic astatine /I/-coordination compounds with selenium-containing neutral ligands is described. The detection of compound formation and first physico-chemical data on the characterization of this new group of At/I/-compounds were obtained by investigation of their electromigration behaviour in free electrolytes. Se-donors coordinate more strongly to At/I/ than ligands containing carbamide and thiocarbamide. This fact is proved by electromigrational studies on the exchange of N,N-ethyleneselenocarbamide, respectively N,N-ethylenethiocarbamide with iodide.     

The reaction of diarylzinc compounds with silver salts : Synthesis and characterization of arylsilver(I) compounds

The reaction of diarylzinc compounds with silver(I) salts is an excellent method of preparing stable arylsilver compounds in quantitative yields. These compounds have been characterized by IR and ¹H and ¹³C NMR spectroscopy Cryoscopy in benzene shows phenylsilver to be polymeric, and the methyl-substituted phenylsilver compounds to be trimers. All the compounds appear to be associated via aryl groups bridging between two silver atoms. As in the case of the corresponding copper compounds, the data point to the existence of rotation of these aryl groups around the C¹C⁴ axis. C¹C⁴ axis.     

Reaction of diarylzinc compounds with copper(I) salts. Synthesis and characterization of arylcopper(I) compounds

The reaction of diarylzinc compounds with copper(I) salts is an excellent way of preparing stable arylcopper compounds in quantitative yields. These compounds have been characterized by IR, and by ¹H and ¹³C NMR spectroscopy. Cryoscopic molecular weight determinations show phenylcopper to be polymeric and 2-methylphenylcopper and 2,6-dimethylphenylcopper to be tetrameric in benzene. The compounds are believed to contain aryl groups bridging two copper atoms. Evidence is presented for rotation of these aryl groups around the C(1)—C(4) axis.     

Synthesis and characterization of organogallium-antimony compounds

The simple Lewis acid–base adduct Me₃Ga←Sb(SiMe₃)₃ (1) was prepared by the reaction of Me₃Ga and Sb(SiMe₃)₃. Dehalosilylation reaction between Me₂GaCl and Sb(SiMe₃)₃ in 1:1 mol ratio yields the trimeric [Me₂GaSb(SiMe₃)₂]₃ (2). 1 and 2 were fully characterized by mass and NMR spectroscopy. In addition, the solid state structure of compound 2 was determined by single crystal X-ray diffraction.     

硫杂蒽酮的合成和表征

为了寻求合成硫杂蒽酮的高效新方法,以2,2′-二硫代二苯甲酸和苯酚为原料,硫酸为溶剂和催化剂,考察了沸石分子筛、Al2O3和P2O5、温度、原料的物质的量之比、反应时间对反应收率的影响,确定了最佳反应条件,推测了可能的反应过程;进而以2,2′-二硫代二苯甲酸和相应的苯衍生物为原料,在H2SO4-P2O5体系中于最佳反应条件下制备了13个硫杂蒽酮类化合物,并利用柱色谱分离以及红外光谱与核磁共振谱对产物进行表征.结果表明,在反应体系中引入P2O5有利于促进反应的完成;最佳反应条件为:温度70℃、2,2′-二硫代二苯甲酸/苯衍生物物质的量之比1∶6、反应时间6h.邻苯二酚与二硫代水杨酸的反应产物——化合物11(a)和11(b)为同分异构体.     

(Halomethyl)arsenic compounds : I. Synthesis and characterization of (chloromethyl)arsine

(Chloromethyl)arsine, ClCH₂Ash₂, can be prepared by the reduction of chloromethylarsonic acid. Bromomethyl and iodomethyl analogs could not be prepared. NMR, IR, and mass spectra data are included.     

Synthesis and characterization of new cyclotriphosphazene compounds

In the present study, spiro (1a), dispiro (1b, 2, 3), per-substituted spermine-bridged (6–9) and dispiroansa spermine (10) derivatives of cyclotriphosphazene have been synthesized. The structures of the novel compounds (1b, 6–10) have been characterized by elemental analysis, FTIR, mass spectrometry, ¹H and ³¹P NMR spectroscopy. The molecular structures of 1b, 2, 8, and 10 were determined by single crystal X-ray crystallography. In order to investigate the anti-tumour properties of the newly synthesized cyclotriphosphazene derivatives, in vitro cytotoxic activity test (MTT assay) has been performed using HT-29 (human colon adenocarcinoma) and Hep2 (human epidermoid larynx carcinoma) cell lines. The result of the MTT assay showed that while compound 1a has cytotoxic effect on both Hep2 and HT-29 cell lines, compound 3 has only cytotoxic effect towards the Hep 2 cells.     

Synthesis, characterization and bromination of bis(phosphinoferrocenyl) gold(I) compounds

Reaction of [(dppf)Au₂Br₂] (3) {dppf = 1,1′-bis(diphenylphosphino)ferrocene} and [(dippf)Au₂Br₂] (4) {dippf = 1,1′-bis(diisopropylphosphino)ferrocene} with excess bromine yields two new complexes [(C₅H₄Br₃)(PR₂)AuBr] (R = Ph, 5; R = i-Pr, 6). Bromination of the free diphosphinoferrocene ligands produces the expected brominated cyclopentenes (C₅H₄Br₃)(PR₂) (R = Ph, 7; R = i-Pr, 8) in good yields; however, these compounds could not be complexed to gold due to reduced basicity of 7 and 8. When the bromination is performed under wet aerobic conditions the oxidized pseudo-centrosymmetric product, [doppf][FeBr₄] (9) {doppf = 1,1′-bis(oxodiphenylphosphino)ferrocene, is formed as the major product. Solid-state structures of 1, 2, 4, 6, and 9 have been established by means of single-crystal X-ray crystallography.     

哒嗪酮类阿拉伯糖苷化合物的合成与表征

近年来科学家和营养学家就阿拉伯糖(Arabinose)在肠道内对糖类代谢的作用作了大量的研究工作:临床试验表明阿拉伯糖对蔗糖的代谢转化具有阻断作用,使其在减肥、控制糖尿病等方面的应用前景看好.     

Synthesis and characterization of deep blue emitters from starburst carbazole/fluorene compounds

A series of well-defined, highly fluorescent starburst compounds with a carbazole core and oligo(2,7-fluorene ethynylene) arms have been synthesized by Sonogashira coupling reaction and fully characterized. These conjugated compounds exhibit good solubility, high thermal stability, and excellent fluorescence quantum yields (up to 0.99). The incorporation of carbazole core interrupted the main-chain conjugation and resulted in blue-shifted absorption and emission. Moreover, deep blue light has been approached from organic light-emitting diodes (OLEDs) adopting these compounds as emitting layer.     

含硅二烃基锡(Ⅳ)邻菲咯啉配合物的合成及结构表征

1980年,Crowe等人首次报道了六配位有机锡(Ⅳ)配合物R2SnX2L2(R=烷基或苯基;X=F,C l,Br,I或NCS;L为含O或N的有机配体)对P388淋巴白血病细胞有抑制活性[1]。以后人们合成许多二烃基锡配合物,并对基作了广泛的研究[2,3]。结果表明,二烃基锡化合物的抗肿瘤活性主要取决于烃基,混合二烃基锡化合物毒性较高,使它们的应用受到一定的限制。在药物分子中,某个碳原子被硅取代,称为硅药(Sila-drug),其特点是能降低毒性,有时也能提高药效[6]。因此,开展对含硅有机锡化合物进行研究,对于探讨分子中引入硅原子后对有机锡化合物性质的影响有一定的…     

Synthesis and characterization of MDI-butanediol urethane model compounds

Hard-segment model compounds containing one to five 4,4′-methylene bis(p-phenylisocyanate) (MDI) units extended with 1,4-butanediol (BD) were synthesized. The ends of the model compounds were reacted with ethanol. The melting point (T_m) of the model compounds increased with the number of MDI units to an extrapolated value of 299°C for the homopolymer using Flory's equation accounting for chain end defects. The ΔH of fusion was 5.3 kcal/mol. Intrinsic viscosity measurements in DMA solutions revealed a Mark Houwink exponent of 1.43 suggesting that the hard-segment model compounds are rodlike in solution. Wide-angle X-ray diffraction showed that the percentage of hard-segment crystallinity decreased as the oligomer length increased. Infrared spectroscopy studies showed that the distribution of hydrogen bond distances between C?O and NH groups became broader with increasing segment length.     

Synthesis and characterization of some new dimesogenic compounds

We have synthesized four different types of dimesogenic compounds involving the cholesteryl moiety as one of the mesogenic constituents, and have investigated their liquid crystalline properties. The molecular structures of these dimesogens have been confirmed by spectral analyses; they exhibit a rich polymorphism, as revealed by optical microscopic and differential scanning calorimetric observations. The studies show that the mesomorphic behaviour is sensitive to the nature of the terminal alkyl chains, and to the structure of the 'second mesogen' that is attached to the cholesteryl unit through a polymethylene spacer.     

卟啉-5-氟尿嘧啶衍生物的合成与表征

5-氟尿嘧啶(5-Fu)是一种作用于DNA合成期的抗恶性肿瘤药物,主要用于消化道癌和乳腺癌,是治疗胃癌的首选药.但它的一大缺点是服药有效剂量与中毒量相近,在杀死癌细胞的同时正常细胞损伤也较严重.     

Calcium alkoxyalanates : I. Synthesis and physicochemical characterization

Soluble calcium alkoxyalanates, Ca[AlH_4?n(OR)_n]₂, in which n ranges from 1 to 3, generally complexed with tetrahydrofuran, have been obtained by partial alcoholysis of calcium alanate with various branched aliphatic alcohols and with 2-methoxyethanol in toluene. With a few exceptions X-ray powder diffraction patterns and infrared AlH absorptions indicate that the calcium alkoxyalanates are individual molecular species.     

Synthesis and characterization of new copper(II) complex compounds with chlorhexidine. Part I

Three new copper(II) complex compounds with chlorhexidine diacetate as a ligand have been prepared and characterized by elemental and thermogravimetrical analyses, molar conductances, magnetic susceptibility measurements, infrared, electronic and EPR spectra. The complexes correspond to the formulas: [Cu₂(CHX)Cl₄]·2C₂H₅OH, [Cu₂(CHX)Br₄]·2C₂H₅OH and [Cu₂(CHX)(CH₃COO)₂] (CH₃COO)₂·2C₂H₅OH, where CHX = chlorhexidine, their composition and stereochemistry depending on the reaction conditions and the metal salt used. Chlorhexidine acts as neutral tetradentate NNNN donor, coordinating through the four imine nitrogen atoms. Investigations on antimicrobial activity in vitro show that all the complexes are active against the tested microorganisms, the complex with chloride being more active against Gram negative bacteria than chlorhexidine diacetate..      

Synthesis, characterization and photophysical properties of benzidine-based compounds

The N-alkylation of the 3,3′-diaminobenzidine with innocent substituents leads to unusual properties. The emission of the benzidine core can be fine-tuned by subtle modifications, and the N-substitution with benzylic groups results in photoinduced exciplexes with distinct and increased emission. This compound constitutes the first example of intramolecular exciplex containing benzidine unit. We also show that these photoinduced processes could be modulated by proton input, and that the diprotonation of the benzidine core disrupted the intramolecular communication in the excited states with a concomitant inhibition of the ligand-centred fluorescence. Furthermore, upon photo-irradiation at 254 nm, semiquinone imine and quinone diimine systems are produced in CH₂Cl₂ of which the photolysis generates Cl radicals, which rapidly oxidize the tetraamine compounds.