【作者】 Sajid H. Guzar；

【导师】 金钦汉；

【作者基本信息】 吉林大学 ， 分析化学， 2009， 博士

【摘要】 腙是含有R2C=NNR2结构的有机甲亚胺类化合物。它们与这类化合物的其他成员(亚胺,肟等等)有明显的区别。一般来讲,腙的制备是将适当化学计量比的肼和醛或者酮的混合物溶解到适当的溶剂中,然后经过回流,冷却后即可析出腙的晶体。在本论文中,我们合成了一种自制配体( 2-pyridinecarboxaldehyde isonicotiny ydrazone )和一种新配体( Pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone)以及它们的铜(II)、钴(II)配合物。1.自制配体2-pyridinecarboxaldehyde isonicotiny hydrazone (2-PYAINH)的合成等摩尔量的2-pyridinecarboxaldehyde和isonicotinoylhydrazine溶解于无水乙醇中,回流2小时,然后冷却到室温,得到的白色沉淀经过滤分离后用热乙醇清洗数次后真空干燥。2.新配体Pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone (PY-2-AINH)的合成等摩尔量的Pyrrolyl-2-carboxaldehyde和isonicotinoylhydrazine溶解于无水乙醇中,回流2小时,然后冷却到室温,得到的白色沉淀经过滤分离后用热乙醇清洗数次后真空干燥。粗产品经热的甲醇水溶液重结晶得到最终产品(熔点:180– 182°C,产率:74 %,颜色:白)。红外光谱数据显示出产物C=O基团的吸收带(1666 cm-1)和C=N基团的吸收带(1552 cm-1)。从吸收带和产物的元素分析结果可以看出所合成的产物为一种全新的化合物。3. Pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone金属配合物的合成首先将0.5 mol的醋酸钴或者醋酸铜溶解于10 mL乙醇中,将此溶液逐滴加入到配体化合物的10 mL乙醇热溶液中。混合物持续回流3小时,冷却,过滤,用乙醇清洗并真空干燥,即可制得相应的金属配合物。需要指出,在制备钴配合物时,应在醋酸钴溶液中滴加一滴冰醋酸以防止其水解。配合物的纯度通过TLC和元素分析来检测。腙在许多应用领域里都是一个非常通用的化合物。腙因其螯合特性而在分析化学中被用作金属的选择性萃取剂和某些过渡金属元素的光谱检测试剂。腙的衍生物被发现具有抗菌、抗结核病、抗惊厥和抗炎活性。在分析化学中,腙作为金属(通常是过渡金属)的多齿配体而得到了广泛的应用。多种研究表明,甲亚胺类化合物在其p轨道或者其三角形杂化氮的sp2杂化轨道上具有一对孤对电子,因此其具有相当重要的生物应用性。腙的分析应用非常广泛。它们被广泛应用于含羰基化合物的检测、测定和分离中。众所周知,腙和它们的配位化合物具有非常重要和有趣的生物学特性,比如它们的抗菌、抗癌和抗结核活性等。由于铜(II)提供的立体化学多功能性,铜(II)配合物的结构和光谱学研究一直以来都是一个令人感兴趣的领域。ESR谱学是一个新兴的、强大的研究手段。它可以阐明固态铜(II)配合物的结构和键联情况,同时也能很好的解释其溶液动力学。它也可以检测由于配体取代或者同一金属多价态而导致的配合物几何构型的变化。此外,研究表明铜(II)的水杨醛苯甲酰腙配合物是一个非常有效的DNA合成和细胞生长的抑制剂。研究发现,一些腙的类似物是潜在的可以治疗遗传性疾病如治疗生成障碍性贫血的药物口服铁螯合剂,或者是治疗神经退行性疾病如阿尔茨海默病的金属螯合剂。目前属于芳香腙类化合物的新型铁螯合剂被证实是治疗等多种人类疾病如铁摄入量过多导致的疾病、癌症、蒽环类抗肿瘤药物引起心脏或肺结核等的潜在药物。水杨醛异烟酰腙(Salicylaldehyde isonicotinoyl hydrazone,SIH)是这一类试剂中最具有应用前景的一个腙的类似物。它除了能够降低铁过载模式中细胞内铁负荷外,还表现出了在心脏免疫保护活动中具有重要的抗氧化应激性损伤的能力。本论文的目的在于研究hydrazone 2-pyridinearboxaldehyde isonicotiny hydrazone对几种金属离子(镍II、铜II、钴II和铁III)的光谱检测方面的分析应用。所用分光光度法的基础是辐射源和物质之间相互作用的简单关系。所研究过的因素包括波长、放置时间和pH值等的影响,还通过摩尔比的方法测定了2-pyridinearboxaldehyde isonicotiny hydrazone和金属离子之间的化学计量关系。考察了在金属离子检测中比尔定律的线性范围。研究了杂质离子对待测金属离子测定的影响。研究了2-pyridinearboxaldehyde isonicotiny hydrazone试剂钴(II)和铜(II)配合物的表征和光谱。结果表明,试剂2-pyridinearboxaldehyde isonicotiny hydrazone提供了一种对几种金属离子(镍II、铜II、钴II和铁III)水溶液的简单、灵敏、具有选择性和直接的光谱检测方法。该方法对镍(II)、铜(II)、钴(II)和铁(II)配合物的最大吸收波长分别为363,352,346和359 nm。这些金属离子配合物的最佳pH值分别为7.0,9.0,8.0和8.0。结果还表明,各种金属-配体配合物的化学计量关系如下:Ni-2-PYAINH,Cu-2-PYAINH,Co-2-PYAINH为1:2;Fe-2-PYAINH为1:1。本法在金属离子浓度分别为Ni(II):0.01-1.4 mg/L;Cu(II):0.01-1.5 mg/L;Co(II):0.01-2.7 mg/L;Fe(II):0.005-5.4 mg/L时符合比尔定律。结果表明,本法对各种金属离子的一次线性回归方程分别为Ni(II):A=0.76C+0.069 ; Cu ( II ): A=0.38C+0.11 ; Co ( II ): A=0.27C+0.26 ; Fe(III):A=0.069C+0.17。相关系数R分别为Ni(II):0.9999(n=6);Cu(II):0.9996(n=10);Co(II):0.9995(n=13);Fe(III):0.9992(n=5)。本法对Ni(II),Cu(II),Co(II),Fe(III)四种金属离子的桑德尔灵敏度和相对标准偏差依次分别为8.4x104;5.2x104;7.1x104;3.9x104 L·mol-1·cm-1,0.00069;0.0012;0.00078;0.0014μg·cm-2和1.01 %;2.02 %;1.72 %;1.81%。本法对Ni(II),Cu(II),Co(II),Fe(III)四种金属离子的检出限依次分别为0.001;0.002;0.003;0.01 mg/L。本论文对一种新配体(Pyrrolyl-2 carboxaldehyde isonicotinoylhydrazone)的制备过程进行了详细的描述。该配体以Pyrrolyl-2-carboxaldehyde与isonicotinoylhydrazine反应制得。同时制备了该配体的铜(II)、钴(II)配合物。并对该配体的铜(II)、钴(II)配合物应用元素分析,磁性和电导率测量,光谱方法,电子自旋共振,红外光谱,核磁共振,热和电子能谱等方法进行了表征。1. PY-2-AINH及其钴(II)铜(II)配合物的分析数据及物理性质从配体和配位化合物的分析数据和物理性质可以看出配体与金属离子的配位摩尔比为2:1。配体在热乙醇和强极性溶剂如DMF和DMSO中可溶。所有的化合物在空气中都可以稳定存在。配合物的熔点高于配体,表明配合物与配体相比具有更好的稳定性。配合物在苯或硝基苯中不溶。配合物的摩尔电导率值在25 ?C时为21.70–22.2 ??1·cm2·mol?1,这表明了配合物的非电解质属性。2.配体及其钴(II)铜(II)配合物的红外光谱配体及其钴(II)、铜(II)配合物的红外光谱显示出特征吸收带为3178,1666,1552,1470和957 cm?1,分别来自于ν(N?H),ν(C=O),ν(C=N),δ(N?H)和ν(N?N)。红外光谱数据揭示了钴(II)、铜(II)配合物与配体相比产生了非常明显的变化。在配合物中属于ν(N?H),ν(C=O)和δ(N?H)的吸收带消失了,出现了两个由共轭体系ν(>C=N?N=C<)和ν(C?O)产生的吸收带,分别为1638–1641和1338–1359 cm?1。ν(C=N)吸收带产生了30–33 cm?1的红移,ν(N?N)吸收带产生了37–43 cm?1的蓝移,表明金属离子与配体通过酰胺甲亚胺氮和氧负离子形成了烯醇式中性配位化合物。ν(C=N)吸收带向低频转移是由于双键上的p-轨道与金属离子的d-轨道共轭而导致力常数降低所致。ν(N?N)吸收带向高频转移是由于形成共轭体系时的电子吸引诱导效应所致。在远红外区配合物的两个新的吸收带543–557和425–438 cm?1可以分别归属于ν(M? O)和ν(M? N)。3. 1H核磁共振谱配体的核磁共振谱─NH (2-pyrrole)质子出现在12.46 ppm,─NH (hydrazid)质子出现在11.76 ppm,2-pyrrole环质子出现在6.15–7.12 ppm(多重态),2-pyridine环质子出现在7.44–8.75 ppm(多重态),etheonyl质子出现在7.94和8.79 ppm(每一个都是双重态)。由于顺磁性的干扰没有得到配合物的1H核磁共振谱。4.电子能谱研究全部配合物的配体场谱是在室温下的DMF溶液中得到的。配体在DMF溶液中的电子能谱显示出n→π*和π→π*跃迁,其吸收谱的两个肩分别为315和295 nm。配合物在DMF溶液中的电子能谱数据与它们的几何构型非常吻合。紫外吸收带显示了电荷位移跃迁(charge transfer transition,CT),对钴(II)铜(II)配合物为385到410 nm,可能来自于配体-金属电荷位移跃迁。5.磁性研究研究发现Co(II)的配合物是顺磁性的,这就排除了平面正方形构型的可能性。测得的Co(II)配合物的磁矩值为3.37 BM,这是四面体几何构型的明显证据。所研究的Cu(II)配合物的磁矩值为1.79 BM,这是平面正方形几何构型的明显证据。6.电子自旋共振谱(ESR)在室温下测定了Cu(II)配合物的电子自旋共振谱参数。所得的Cu(II)配合物的g值较低,表明Cu(II)配合物有更多的平面共价键,两个配体象二齿配体一样以N,O为电子给予体。从测得的g值明显看出未成对电子主要存在于dx2–y2轨道,这意味着是一个2B1g的基态。Cu(II)配合物的g值大于2,表明配合物中存在Cu─O和Cu─N键,正如Kivelson和Neiman所提出的那样,可以用Cu(II)配合物的gII值来表征金属-配体共价键。就离子环境而言,其gII值通常是2.3或者更高,对于共价键环境而言,其gII值小于2.3。使用这一判断标准,当前配合物的金属-配体键具有非常明显的共价键特征。7.热分析在20–850 ?C温度范围内对配体及其配合物进行了热示重(TG)和差热分析(DTA)研究。从配体的DTA分析曲线可以看出在400-460 ?C之间有三个吸热峰但是只有一个放热峰。出现在172 ?C的第一个峰为配体的熔点,因为在TG曲线上没有观察到重量的损失。出现在250 ?C以上的第二和第三个峰预示着配体的分解,相应的TG曲线上观察到重量损失。大约在390 ?C时配体分解完全,这里有一个有机残留物高温分解产生的放热峰。配合物的热分解曲线与配体的不同。DTA曲线上没有吸热峰,只有一系列的放热峰,表明这些配合物没有熔点。Cu(II)配合物的第一步分解在280–320 ?C,第二步分解从370 ?C开始一直持续上升到500 ?C。Co(II)配合物的第一步分解在320–360 ?C之间,第二步分解从390 ?C开始一直持续上升到470 ?C。从TG曲线上看,Co(II)配合物的失重有三个阶段:(1)从300到320 ?C之间失去30 %的重量;(2)从320到420 ?C之间,由于有机组分高温分解而失去大约65 %的重量;(3)从420到470 ?C之间由于有机残留物高温分解而失去5 %的重量。从TG曲线上看,Cu(II)配合物的失重有三个阶段:(1)从240到270 ?C之间失去55 %的重量;(2)从270到380 ?C之间,由于有机组分高温分解而失去大约30 %的重量;(3)从380到440 ?C之间由于有机残留物高温分解而失去15 %的重量。本论文对实际样品进行了分析。为检验所提出的方法的适用性,用论文所建的模型对实际样品中的钴、铜、镍和铁进行了测定。为此,我们对两种矿泉水和一种自来水进行了分析。每种样品中都加入1 mg/L的金属离子。所有的样品都得到了非常好的回收率。本论文具有如下创新点:1.首次合成了具有选择性和灵敏性的试剂2-pyridinecarboxaldehyde isonicotinylhydrazone (2-PYAINH),对痕量镍、铜、钴和铁进行了详细光谱测量研究。2.所提出的方法是对水溶液中痕量镍、铜、钴和铁进行光谱测定的最有选择性、灵敏性、经济和快速的方法之一。3.所提出的方法不需要任何萃取和预富集过程。4.本方法成功应用于两种矿泉水和一种自来水中金属离子的测定。5.本论文所报道的检出限与相似方法相比非常具有挑战性。6.结果的完美吻合证明了本法对复杂样品如生物材料中铁、钴、镍和铜的测定不需要冗长乏味的样品预处理过程。7.应用元素分析、光谱方法、磁性和电导率测量及热分析对所合成的配合物进行了结构表征。从光谱表征可以得出化合物Pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone (PY-2-AINH)是作为二齿配体通过羰基氧和甲亚胺氮进行配位的。8.由于所合成的Cu(II)和Co(II)的PY-2-AINH配合物在环境样品分析中非常稳定,因此本法可以扩展到批量制药和配方的常规分析中。更多还原

【Abstract】 Hydrazones are azomethines characterized by the grouping C N N . They are distinguished from other members of this class (imines, oximes,……etc). Hydrazones in general are prepared by refluxing the stoichiometric amounts of the appropriate hydrazine and aldehyde or ketone dissolved in a suitable solvent. The compound usually crystallize out on cooling.In this thesis we report the synthesis of a home-made ligand (2-pyridinearboxaldehyde isonicotiny ydrazone) and a new ligand (Pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone) and its Copper (II) and Cobalt (II) complex.1. Synthesis of a home-made ligand 2-pyridinearboxaldehyde isonicotiny hydrazone(2-PYAINH)Equimolar solutions of 2-pyridinecarboxaldehyde and isonicotinoylhydrazine in anhydrous ethanol were refluxed for 2 h, then the contents were cooled to room temperature; the white precipitate was separated by filtration, washed with hot ethanol and dried in vacuum.2. Synthesis of a new ligand pyrrolyl-2-carboxaldehyde isonicotinoylhydrazone(PY-2-AINH)Equimolar solutions of pyrrolyl-2-carboxaldehyde and isonicotinoylhydrazine in anhydrous ethanol were refluxed for 2 h, then the contents were cooled to room temperature; the white precipitate was separated by filtration, washed with hot ethanol and dried in vacuum. Recrystallized from hot aqueous methanol (m. p. 180-182°C, 74 % yield, and color is white). The band at 1666 cm-1 is due to the C=O group and absorption bands at 1552 cm-1 due to the C=N group of the reagent, from these absorption bands and elemental analyses of the reagent, one can conclude that the newly synthesized compound is a novel reagent. 3. Synthesis of complexes of pyrrolyl-2-carboxaldehyde isonicotinoylhydrazoneThe complexes were prepared by adding metal acetate (0.5 mo1) [metal = Co (II), and Cu (II)] in ethanol (10 ml) dropwise to the hot solution of ligand in ethanol (10 ml). The mixture was maintained under reflux for 3 h, then cooled, filtered, washed with ethanol and dried in vacuum. While preparing the cobalt complex, a drop of glacial acetic acid was added to the cobalt acetate solution to prevent its hydrolysis. The purity of complexes was checked by TLC and elemental analyses.Hydrazones are a versatile class of compounds with several applications. Due to their chelating behavior, hydrazones are used in analytical chemistry as selective metal extracting agents as well as in spectroscopic determination of certain transition metals. Hydrazone derivatives are found to possess antimicrobial, anti-tubercular, anti-convulsant and anti-inflammatory activities.In analytical chemistry, hydrazones find application by acting as multidentate ligands with metals (usually from the transition group). Various studies have also shown that the azomethine group having a lone pair of electrons in either a p or sp2 hybridized orbital on trigonally hybridized nitrogen has considerable biological importance.Hydrazones found a wide analytical application. They are extensively used in the detection, determination and isolation of the compounds containing carbonyl group. Hydrazones and their coordination compounds are well known to be biologically important and interest for their antibacterial, antitumour and antitubercular activities. Structural and spectral investigations on copper (II) complexes continue to be interesting because of the stereochemical versatility offered by copper(II). ESR spectroscopy has emerged as another powerful method for elucidating the solid state structure and bonding as well as for understanding the solution dynamics of copper(II) complexes. It also detects variations in coordination geometry due to ligand substituents as well as multiple valencies of the same metal. Moreover, the copper(II) complex of salicylaldehyde benzoylhydrazone was shown to be a potent inhibitor of DNA synthesis and cell growth. Some hydrazone analogues have been investigated as potential oral iron chelating drugs for the treatment of genetic disorders such as thalassemia and have also been suggested as possible metal chelating agents for treating neurodegenerative disorders such as Alzheimer disease. Novel iron chelating agents belonging to the group of aromatic hydrazones are currently investigated as potential drugs for the treatment of various human pathologies, including iron overload-associated diseases, cancer, anthracycline-induced cardiotoxicity and tuberculosis. Salicylaldehyde isonicotinoyl hydrazone (SIH) is among the most promising agents of this group. Besides its ability to reduce cellular-iron burden in iron-overload models, it has been also shown to possess significant cardioprotective activity against oxidative stress-induced injuryThe aim of this thesis is concerned with the analytical application of the hydrazone 2-pyridinearboxaldehyde isonicotiny hydrazone as a reagent for the spectrophotometric determination of several ions such as (Nickel(II), Copper(II), Cobalt(II) and Iron(III)). The basis of spectophotometric methods is the simple relationship between interaction of a beam of radiation and matter.Several factors includes wavelength, standing time and pH have been studies, the study also includes the determination of the stoichiometric of 2-pyridinearboxaldehyde isonicotiny hydrazonewith metal ions by molar-ratio method.The linearity range of Beer’s law for the determination of metal ion was examined. The effect of the foreign ions on the determination of the interested metal ions has been investigated.The results showed that the reagent 2-pyridinearboxaldehyde isonicotiny hydrazone provides a simple, sensitive, selective and direct method for the spectophotometric determination of (nickel(II), copper(II), cobalt(II) and iron(III)) in the aqueous solution. This method gives it’s maximum absorption values at wavelengths of 363, 352, 346 and 359 nm, respectively. Also, preferable pH values for the complexation of these metal ions were 7.0, 9.0, 8.0 and 8.0, respectively.The results also showed that the stoichiometry of metal-ligand complexes were 1:2 for Ni-2-PYAINH, 1:2 for Cu-2-PYAINH, 1:2 for Co-2-pyridinearboxaldehyde isonicotiny hydrazoneand and 1:1 for Fe-2-PYAINH.This method obeys Beer’s law in the range of 0.01-1.4, 0.01-1.5, 0.01-2.7 and 0.005-5.4 mg/L for nickel (II), copper (II), cobalt (II) and iron (III), respectively.The results show that, the simple linear-regression calibration equations for nickel (II), copper (II), cobalt (II) and iron (III), A=0.76C+0.069, A=0.38C+0.11, A=0.27C+0.26 and A=0.069C+0.17, with correlation coefficient of 0.9999 (n=6), 0.9996 (n=10), 0.9995 (n=13) and 0.9992 (n=5), respectively.The results also show that, Sandell’s sensitivities and relative standard deviations were 8.4x104, 5.2x104, 7.1x104 and 3.9x104 L mol-1 cm-1, 0.00069, 0.0012, 0.00078 and 0.0014μg cm-2, and 1.010%, 2.023%, 1.715% and 1.813%, for nickel (II), copper (II), cobalt (II) and iron (III), respectively.The results show that, the detection limits were found to be 0.001, 0.002, 0.003 and 0.01 mg/L, for nickel (II), copper (II), cobalt (II) and Iron (III), respectively.This thesis describes the preparation of the new ligand (pyrrolyl-2 carboxaldehyde isonicotinoylhydrazone), obtained in the reaction of pyrrolyl-2-carboxaldehyde with isonicotinoylhydrazine, and its copper (II) and cobalt (II) complex. These copper (II) and cobalt (II) complexes are characterized by elemental analyses, magnetic and conductance measurements, spectroscopic methods, ESR, IR, 1H NMR, thermal studies and electronic spectral studies.1. The analytical data and physical properties of P-2-AINH and of cobalt (II) and copper (II) complexes. the results from analytical data and physical properties of the ligands and coordination compounds show that the ligand coordinates to the metal ion in a 2:1 molar ratio. The ligands are soluble in hot ethanol and strong polar solvents such as in DMF and DMSO. All compounds are stable in air. The melting points of the complexes are higher than that of the ligands revealing that the complexes are much more stable than the ligands. Due to insolubility of the complexes in benzene/nitrobenzene the molar conductance values of the complexes was shown to be in the range 21.70–22.2 --1 cm2 mol-1 (at 25 -C) which indicates that the complexes are of non-electrolytic nature.2. Infrared spectra of ligand and cobalt (II) and copper (II) complexThe IR spectra of the ligand and cobalt (II) and copper (II) complex show characteristic absorption bands at 3178, 1666, 1552, 1470 and 957 cm-1 due toν(N-H),ν(C=O),ν(C=N),δ(N-H) andν(N-N), respectively. The IR spectra of the ligand, Co(II) complex and Cu(II) complex, respectively, reveal significant changes compared to the ligand. The absorption bands attributed toν(N-H),ν(C=O) andδ(N-H) disappeared in the complexes and two new bands due to conjugate systemν(>C=N-N=C<) andν(C-O) appeared in the regions 1638–1641 and 1338–1359 cm-1, respectively. The band forν(C=N) undergoes a bathochromic shift of 30–33 cm-1 (in HL) andν(N?N) band exhibited a hypsochronic shift of 37–43 cm?1 (in HL) which indicate that the metal ions form neutral coordination compounds with the ligand in the enol form through the azomethine nitrogen and amide oxygen negative ion . A shift ofν(C=N) band to a lower frequency is due to the conjugation of the p-orbital on the double bond with the d-orbital on metal ion with reduction of the force constant. A shift ofν(N?N) band to a higher frequency is attributed to the electron attracting inductive effect when forming the conjugated system. In the far-IR region two new bands around 543–557 and 425–438 cm?1 in the complexes can be assigned toν(M? O) andν(M? N), respectively.3. 1H NMR spectraThe NMR spectrum of the ligands exhibits─NH (2-pyrrole) proton at 12.46 ppm,─NH (hydrazid) proton at 11.76 ppm, 2-pyrrole ring protons at 6.15–7.12 ppm (multiplets), 2-pyridine ring protons at 7.44–8.75 ppm (multiplets) and etheonyl protons at 7.94 and 8.79 ppm (each as a doublet). The 1H NMR spectra of the complexes cannot be obtained due to interference in their paramagnetic properties.4- Electronic spectral studiesThe ligand field spectra of all the complexes were recorded in DMF at room temperature. The electronic spectrum of the ligand in DMF showed the n→π* andπ→π* transitions as a band with a shoulder at 315 and 295 nm, respectively. The electronic spectral data of the complexes in DMF are in good agreement with their geometries. The UV absorption bands exhibit a charge transfer transition (CT) in the range 385 to 410 nm for Co(II) and Cu(II) complexes and may be assigned to the ligand-to-metal charge transfer transition.5- Magnetic studiesThe cobalt(II) complex was found to be paramagnetic which excludes the possibility of square planar configuration. The measured magnetic moment value for cobalt(II) complex of 3.37 BM is an evidence for tetrahedral geometry. The magnetic moment value of the copper(II) complex under study, 1.79 BM, is an evidence for square planar geometry.6- Electron spin resonance spectroscopy (ESR)The powder ESR parameters of the copper(II) complex measured at room temperature. The low g-value of copper(II) complex, indicating more covalent planar bonding and two ligands are likely bidentate, N, O, donor. From the observed g-values, it is clear that the unpaired electron lies predominantly in the dx2–y2 and implying a 2B1g as a ground state. The g-value for copper(II) complexes is greater than 2 indicating to the presence of Cu─O and Cu─N bonds as Kivelson and Neiman have suggested that the g11 value in the Cu(II) complex can be used as a measure of covalent character of the metal–ligand bond. For the ionic environment, the gII value is normally 2.3 or higher and for the covalent environment, it is less than 2.3. Using this criterion, the data show considerable covalent character of the metal–ligand bonding of the present complex.7. Thermal analysisTG and DTA studies were carried out on the ligand and its complexes in the temperature range of 20–850 ?C. The thermal analyses show that there are three endothermic peaks and only one exothermic peak in the range of 400-460 ?C in the DTA curve of the ligand. The first appeared at 172 ?C is melting point of the ligand, because no loss of weight was observed in the TG curve. The second and third peaks appeared above 250 ?C where the weight loss on the corresponding TG curve indicates decomposition of the ligand. The decomposition is complete at about 390 ?C where an exothermic peak arises from the pyrolysis of the organic residues. The thermal decomposition curves of the complexes are different from that of the ligand. There is no endothermic peak, only a series of exothermic ones in the DTA curves indicating no melting points for these complexes .The first step of decomposition of the Cu(II) complex is at 280–320 ?C. The second step of decomposition of the Cu(II) complex starts from about 370 ?C and continues up to 500 ?C. The first step of decomposition of the Co(II) complex is at 320–360 ?C. The second step of decomposition of the Co(II) complex starts from about 390 ?C and continues up to 470 ?C . There are three stages of weight loss of Co(II) complex seen from the TG curve: (1) from 300 to 320 ?C, 30% weight loss and (2) from 320 to 420 ?C, about 65% weight loss due to the pyrolysis of organic compounds; (3) 5% weight loss from 420 to 470 ?C arising from the pyrolysis of the organic residues. There are also three stages of weight loss of Cu (II) complex seen from the TG curve: (1) from 240 to 270 ?C, 55% weight loss (2) from 270 to380 ?C, about 30% weight loss due to the pyrolysis of organic compounds; (3) 15% weight loss from 380 to 440 ?C arising from the pyrolysis of the organic residues. This thesis describes the analysis of real samples. In order to test the applicability of the proposed method, it has been applied for determination of cobalt, copper, nickel and iron in real samples. For this we analysed two mineral and one tap water samples. To each sample was added 1 mg/L of metal ions. In all the samples, extremely good recoveries have been obtained.Through the studying of this method, it was noticed that:1. Selective and sensitive reagent of 2-pyridinecarboxaldehyde isonicotinylhydrazone (2-PYAINH) was for the first time synthesized and studied for the spectrophotometric determination of trace amounts of nickel, copper, cobalt and iron in detail.2. Proposed method is one of the most selective, sensitive, economy and rapid methods for spectrophotometric determination of trace amounts of nickel, copper, cobalt and iron in the aqueous solution3. Proposed method does not require any extraction or pre-concentration step.4. The methods were applied successfully for the analysis of metal ions in two mineral and one tap water samples.5. The limits of detection herein reported are extremely challenging, if compared with similar methods.6. The good agreement clearly demonstrates the utility of this procedure for the determination of iron, cobalt, nickel and copper without tedious pretreatment in complex samples such as biological materials.7. The structural characterizations of synthesized complexes were made by using the elemental analysis, spectroscopic methods, magnetic and conductance measurements, thermal studies. From the spectroscopic characterization, it is concluded that Pyrrolyl- 2-carboxaldehyde isonicotinoylhydrazone(PY-2-AINH) acts as a bidentate ligands, coordinating through carbonyl oxygen and azomethine nitrogen.8. Because of the stable complex of Cu(II) and Co(II) (PY-2-AINH) made to study in environmental samples may be extended to the routine analysis of pharmaceutical samples of bulk and formulations.更多还原