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The study of the fragmentations of the protonated molecular species[M H]~ and selected fragment ions al-lowed proposals for the main fragmentation pathways of the title compound.In order to better understand the frag-mentation pathways,the MS~3 and MS~4 spectra of the title compound were obtained.The main fragmentation path-ways occur by the cleavage of the C-CO bonds between N-methylpyrrole and carbonyl groups,CO-NH amidebonds,NH-C bonds between the NH groups and the N-methylpyrrole rings,and N-C bonds in1,4,7,10-tetraazacyclododecane.Electrospray ionization was proven to be a good method for the structural charac-terization and identification of this kind of compound. 相似文献
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A novel β‐cyclodextrin dimer, 2, 2′‐o‐phenylenediseleno‐bridged bis (β‐cyclodextrin) (2), has been synthesized by reaction of mono‐[2‐O‐(p‐tolylsulfonyl)]‐β‐cyclodextrin and poly(o‐phenylenediselenide). The complexation stability constants (K2) and Gibbs free energy changes (‐ΔG°) of dimer 2 with four fluorescence dyes, that is, ammonium 8‐anilino‐1‐naphthalenesulfonate (ANS), sodium 6‐(p‐toluidino)‐2‐naphthalenesulfonate (TNS), Acridine Red (AR) and Rhodamine B (RhB) have been determined in aqueous phosphate buffer solution (pH = 7.2, 0.1 mol‐L?1) at 25 °C by means of fluorescence spectroscopy. Using the present results and the previously reported corresponding data of β‐cyclodextrin (1) and 6, 6′‐o‐phenylenediseleno‐bridged bis (β‐cyclodextrin) (3), binding ability and molecular selectivity are compared, indicating that the bis (β‐cyclodextrin)s 2 and 3 possess much higher binding ability toward these dye molecules than parent β‐cyclodextrin 1, but the complex stability constant for 2 linked from the primary side is larger than that of 3 linked from the secondary side, which is attributed to the more effective cooperative binding of two hydrophobic cavities of host 3 and the size/shape‐fit relationship between host and guest. The binding constant (K2,) upon inclusion complexation of host 3 and AR is enhanced by factor of 27.3 as compared with that of 1. The 2D 1H NOESY spectrum of host 2 and RhB is performed to confirm the binding mode and explain the relative weak binding ability of 2. 相似文献
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Synthesis and characterization of the ligand, 10-(α-hexadecylcarboxymethyl)- 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (H4L), and its Gd(Ⅲ) chelate are described. Protonation constants for H4L ( lg Ki^H = 10.52, 9.45,4.74, 4.10) and the stability constant for GdL^-(lg KGdL^-=24.50) were determined by potentiometric titrations.The results obtained show that the ligand still maintains the strong chelating properties of the parent DOTA(1,4,7,10-tetraazacyclododecane-N,N‘,N“N′“-tetraacetic acid) after introduction of a linear chain hexadecyl group at the acetic side chain of DOTA, and its basicity is not significantly altered. 相似文献
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1 INTRODUCTION The complexes containing dithiolate ligands have played a well-established role in modern coordination chemistry[1]. There is continuous interest in complexes of chalcogenolate ligands with transition metals such as complexes of Pd[1], Mo[1], Au[2], Ir[3~6], Rh[4, 5], Co[7] and Re[1, 8] containing a chelating 1,2-dicarba-closo-dodecabarane-1,2-dich- alcogenolate ligand. Some of these complexes have become important in the study of new molecular materials[1, 9, 10]. Th… 相似文献
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A. A. Soliman 《Journal of Thermal Analysis and Calorimetry》2001,63(1):221-231
New cadmium complexes of the salicylidene-2-amino-thiophenol (I) and 3-methoxysalicylidene-2-amino-thiophenol (II) Schiff bases have been prepared and characterized by elemental analyses, IR, 1H-NMR spectra, conductimetric and thermogravimetric analyses. The results suggested that the Schiff bases are bivalent anions with tridentate ONS donors derived from the phenolic oxygen azomethine nitrogen and thiophenolic sulphur. The formulae are found to be [MLH2O] and [ML2]for the 1:1 and 1:2 non-electrolytic complexes, respectively. The thermal decomposition of the complexes follows first order kinetics and the thermodynamic parameters of the decomposition are reported.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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Synthesis and Structural Features of New Schiff Base Complexes of Mononuclear MnIV,Dinuclear CoIICoIII,and Tetranuclear CuII 下载免费PDF全文
Davi F. Back Gelson Manzoni de Oliveira Cibele Mensch Canabarro Bernardo Almeida Iglesias 《无机化学与普通化学杂志》2015,641(5):941-947
2‐(((2‐Hydroxy‐3‐methoxyphenyl)methylene)amino)‐2(hydroxymethyl)‐1,3‐propanediol (LH4, as abbreviation) reacts with MnCl2 · 4H2O, CoCl2 · 6H2O, and Cu(ClO4)2 · 6H2O to give the new complexes [Mn(LH2)2] ( 1 ), [Co2Cl(H2O)(LH2)2] · 4H2O ( 2 ), and [Cu4(LH2)4(H2O)4] ( 3 ). Complex 1 is formed by the assembly of two molecules of the ligand with one manganese(IV) ion. In the mixed‐valence cobalt complex 2 there is an asymmetry between the coordination spheres of cobalt(II) and cobalt(III). In the tetramer 3 four copper(II) ions attain a distorted tetrahedral configuration surrounded by four molecules of the ligand. 相似文献
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新型Schiff碱单核配合物的合成及光谱特征 总被引:1,自引:0,他引:1
首次报道了新型Schiff碱配合物-双[N,N’-亚乙基-2,2’-(苯亚甲基)二(3,4-二甲基吡咯-5-醛缩亚胺)]合单金属配合物MH_2L[M=Mn(Ⅱ)、Fe(Ⅲ)Cl、Cr(Ⅲ)Cl、Cu(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)]的合成方法及光谱特征。 相似文献
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B. Meltem Ateş Bülent Zeybek Dr. Mecit Aksu Ümit Ergun Filiz Ercan M. Levent Aksu Orhan Atakol 《无机化学与普通化学杂志》2010,636(5):840-845
Mononuclear nickel(II) complexes were prepared by reaction of the three ONNO type reduced Schiff bases bis‐N,N′‐(2‐hydroxybenzyl)‐1,3‐propanediamine (LHH2), bis‐N,N′‐(2‐hydroxybenzyl)‐2,2′‐dimethyl‐1,3‐propanediamine (LDMHH2), and bis‐N,N′‐[1‐(2‐hydroxyphenyl)ethyl]‐1,3‐propanediamine (LACHH2) with NiII ions in the presence of pseudo halides (OCN–, SCN– and N3–). The complexes were characterized with the use of elemental analyses, IR spectroscopy, and thermal analyses. The molecular structure of one of the complexes was obtained by single‐crystal X‐ray diffraction. The obtained complexes are mononuclear, and a pseudo halide molecule is attached. One of the oxygen atoms of the ligand is in phenolate and the other was in phenol form. According to the thermogravimetry results, it was thought that the pseudo halide thermally detaches from the structure as hydropseudo halide. In azide‐containing complexes an endothermic reaction was observed although the azide group usually decomposes with an exothermic reaction. 相似文献
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Diorganotin dichloride compounds, Rl2SnCl2 (R=Me, nBu, Ph) react with Schiff bases (L), derived from substituted and non-substituted 2- or 3-aminopyridine with 2-hydroxy-, 2-methoxy- or 2-hydroxy-3-methoxy-benzaldehyde in a 1 : 1 molar ratio, to give complexes of general formula R2SnCl2·L. It is suggested that the Schiff bases coordinate with tin in bidentate fashion to give hexacoordinate tin species. Almost all the complexes prepared show some 1 : 1 molar conductivity in ethanol and DMF, indicating on R2Sn(L)Cl+ Cl− ionic structure type. The complexes were screened against seven species of bacteria. 相似文献
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Partial molar volumes of cytosine, uracil, thymine, cytidine, uridine, thymidine, and adenosine have been measured in different concentrations of aqueous ethanol, 1,2-ethanediol, 2-propanol, and 2-methyl-2-propanol at 25°C using densimetry. These data are utilized in conjunction with the partial molar volumes of these nucleic acid bases and nucleosides in water reported earlier to deduce the partial molar volumes of transfer from water to aqueous alcohol or diol. The results are explained in terms of likely solute–solvent interactions; the role of solvent in these interactions is discussed. The partial molar volume data are also used to calculate the contribution of –CH2- groups in the nucleic acid base or solvent and of ribose in the nucleoside to the partial molar volume of transfer. The validity of group additivity in these systems is discussed. 相似文献