Inorganic Chemistry翻譯.doc

新編化學(xué)化工專業(yè)英語 Inorganic ChemistryInorganic chemistry is the branch of chemistry concerned with the properties and reactions of inorganic compounds. This includes all chemical compounds except the many which are based upon chains or rings of carbon atoms, which are termed organic compounds and are studied under the separate heading of organic chemistry. The distinction between the two disciplines is not absolute and there is much overlap, most importantly in the sub-discipline of organometallic chemistry. 1 Key conceptsThe bulk of inorganic compounds occur as salts, the combination of cations and anions joined by ionic bonding. Examples of cations are sodium Na+, and magnesium Mg2+ and examples of anions are oxide O2 and chloride Cl. As salts are neutrally charged, these ions form compounds such as sodium oxide Na2O or magnesium chloride MgCl2. The ions are described by their oxidation state and their ease of formation can be inferred from the ionization potential (for cations) or from the electron affinity (anions) of the parent elements.Important classes of inorganic compounds are the oxides, the carbonates, the sulfates and the halides. Many inorganic compounds are characterized by high melting points. Inorganic salts typically are poor conductors in the solid state. Another important feature is their solubility in e.g. water, and ease of crystallization. Where some salts (e.g. NaCl) are very soluble in water, others (e.g. SiO2) are not.The simplest inorganic reaction is double displacement when in mixing of two salts the ions are swapped without a change in oxidation state. In redox reactions one reactant, the oxidant, lowers its oxidation state and another reactant, the reductant, has its oxidation state increased. The net result is an exchange of electrons. Electron exchange can occur indirectly as well, e.g. in batteries, a key concept in electrochemistry.When one reactant contains hydrogen atoms, a reaction can take place by exchanging protons in acid-base chemistry. In a more general definition, an acid can be any chemical species capable of binding to electron pairs is called a Lewis acid; conversely any molecule that tends to donate an electron pair is referred to as a Lewis base. As a refinement of acid-base interactions, the HSAB theory takes into account polarizability and size of ions.Inorganic compounds are found in nature as minerals. Soil may contain iron sulfide as pyrite or calcium sulfate as gypsum. Inorganic compounds are also found multitasking as biomolecules: as electrolytes (sodium chloride), in energy storage (ATP) or in construction (the polyphosphate backbone in DNA).The first important man-made inorganic compound was ammonium nitrite for soil fertilization through the Haber process. Inorganic compounds are synthesized for use as catalysts such as vanadium(V) oxide and titanium(III) chloride, or as reagents in organic chemistry such as lithium aluminium hydride.Subdivisions of inorganic chemistry are organometallic chemistry, cluster chemistry and bioinorganic chemistry. These fields are active areas of research in inorganic chemistry, aimed toward new catalysts, superconductors, and therapies.2 Descriptive inorganic chemistryDescriptive inorganic chemistry focuses on the classification of compounds based on their properties. Partly the classification focuses on the position in the periodic table of the heaviest element (the element with the highest atomic weight) in the compound, partly by grouping compounds by their structural similarities. When studying inorganic compounds, one often encounters parts of the different classes of inorganic chemistry (an organometallic compound is characterized by its coordination chemistry, and may show interesting solid state properties).Different classifications are:u Coordination compoundsClassical coordination compounds feature metals bound to “l(fā)one pairs” of electrons residing on the main group atoms of ligands such as H2O, NH3, Cl, and CN. In modern coordination compounds almost all organic and inorganic compounds can be used as ligands. The “metal” usually is a metal from the groups 3-13, as well as the trans-lanthanides and trans-actinides, but from a certain perspective, all chemical compounds can be described as coordination complexes.The stereochemistry of coordination complexes can be quite rich, as hinted at by Werners separation of two enantiomers of Co(OH)2Co(NH3)4)36+, an early demonstration that chirality is not inherent to organic compounds. A topical theme within this specialization is supramolecular coordination chemistry. Examples: Co(EDTA), Co(NH3)63+, TiCl4(THF)2. u Main group compoundsThese species feature elements from groups 1, 2 and 13-18 (excluding hydrogen) of the periodic table. Due to their often similar reactivity, the elements in group 3 (Sc, Y, and La) and group 12 (Zn, Cd, and Hg) are also generally included. Main group compounds have been known since the beginnings of chemistry, e.g. elemental sulfur and the distillable white phosphorus. Experiments on oxygen, O2, by Lavoisier and Priestley not only identified an important diatomic gas, but opened the way for describing compounds and reactions according to stoichiometric ratios. The discovery of a practical synthesis of ammonia using iron catalysts by Carl Bosch and Fritz Haber in the early 1900s deeply impacted mankind, demonstrating the significance of inorganic chemical synthesis. Typical main group compounds are SiO2, SnCl4, and N2O. Many main group compounds can also be classed as “organometallic”, as they contain organic groups, e.g. B(CH3)3). Main group compounds also occur in nature, e.g. phosphate in DNA, and therefore may be classed as bioinorganic. Conversely, organic compounds lacking (many) hydrogen ligands can be classed as “inorganic”, such as the fullerenes, buckytubes and binary carbon oxides. Examples: tetrasulfur tetranitride S4N4, diborane B2H6, silicones, buckminsterfullerene C60. u Transition metal compoundsCompounds containing metals from group 4 to 11 are considered transition metal compounds. Compounds with a metal from group 3 or 12 are sometimes also incorporated into this group, but also often classified as main group compounds.Transition metal compounds show a rich coordination chemistry, varying from tetrahedral for titanium (e.g. TiCl4) to square planar for some nickel complexes to octahedral for coordination complexes of cobalt. A range of transition metals can be found in biologically important compounds, such as iron in hemoglobin. Examples: iron pentacarbonyl, titanium tetrachloride, cisplatin u Organometallic compoundsUsually, organometallic compounds are considered to contain the M-C-H group. The metal (M) in these species can either be a main group element or a transition metal. Operationally, the definition of an organometallic compound is more relaxed to include also highly lipophilic complexes such as metal carbonyls and even metal alkoxides.Organometallic compounds are mainly considered a special category because organic ligands are often sensitive to hydrolysis or oxidation, necessitating that organometallic chemistry employs more specialized preparative methods than was traditional in Werner-type complexes. Synthetic methodology, especially the ability to manipulate complexes in solvents of low coordinating power, enabled the exploration of very weakly coordinating ligands such as hydrocarbons, H2, and N2. Because the ligands are petrochemicals in some sense, the area of organometallic chemistry has greatly benefited from its relevance to industry. Examples: Cyclopentadienyliron dicarbonyl dimer (C5H5)Fe(CO)2CH3, Ferrocene Fe(C5H5)2, Molybdenum hexacarbonyl Mo(CO)6, Diborane B2H6, Tetrakis(triphenylphosphine)palladium(0) PdP(C6H5)34 u Cluster compoundsClusters can be found in all classes of chemical compounds. According to the commonly accepted definition, a cluster consists minimally of a triangular set of atoms that are directly bonded to each other. But metal-metal bonded dimetallic complexes are highly relevant to the area. Clusters occur in “pure” inorganic systems, organometallic chemistry, main group chemistry, and bioinorganic chemistry. The distinction between very large clusters and bulk solids is increasingly blurred. This interface is the chemical basis of nanoscience or nanotechnology and specifically arise from the study of quantum size effects in cadmium selenide clusters. Thus, large clusters can be described as an array of bound atoms intermediate in character between a molecule and a solid. Examples: Fe3(CO)12, B10H14, Mo6Cl142, 4Fe-4S u Bioinorganic compoundsBy definition, these compounds occur in nature, but the subfield includes anthropogenic species, such as pollutants (e.g. methylmercury) and drugs (e.g. Cisplatin). The field, which incorporates many aspects of biochemistry, includes many kinds of compounds, e.g. the phosphates in DNA, and also metal complexes containing ligands that range from biological macromolecules, commonly peptides, to ill-defined species such as humic acid, and to water (e.g. coordinated to gadolinium complexes employed for MRI). Traditionally bioinorganic chemistry focuses on electron- and energy-transfer in proteins relevant to respiration. Medicinal inorganic chemistry includes the study of both non-essential and essential elements with applications to diagnosis and therapies. Examples: hemoglobin, methylmercury, carboxypeptidase u Solid state compoundsThis important area focuses on structure, bonding, and the physical properties of materials. In practice, solid state inorganic chemistry uses techniques such as crystallography to gain an understanding of the properties that result from collective interactions between the subunits of the solid. Included in solid state chemistry are metals and their alloys or intermetallic derivatives. Related fields are condensed matter physics, mineralogy, and materials science. Examples: silicon chips, zeolites, YBa2Cu3O7 3 Characterization of inorganic compoundsBecause of the diverse range of elements and the correspondingly diverse properties of the resulting derivatives, inorganic chemistry is closely associated with many methods of analysis. Older methods tended to examine bulk properties such as the electrical conductivity of solutions, melting points, solubility, and acidity. With the advent of quantum theory and the corresponding expansion of electronic apparatus, new tools have been introduced to probe the electronic properties of inorganic molecules and solids. Often these measurements provide insights relevant to theoretical models. For example, measurements on the photoelectron spectrum of methane demonstrated that describing the bonding by the two-center, two-electron bonds predicted between the carbon and hydrogen using Valence Bond Theory is not appropriate for describing ionisation processes in a simple way. Such insights led to the popularization of molecular orbital theory as fully delocalised orbitals are a more appropriate simple description of electron removal and electron excitation.Commonly encountered techniques are: X-ray crystallography: This technique allows for the 3D determination of molecular structures. Various forms of spectroscopy o Ultraviolet-visible spectroscopy: Historically, this has been an important tool, since many inorganic compounds are strongly colored o NMR spectroscopy: Besides 1H and 13C many other “good” NMR nuclei (e.g. 11B, 19F, 31P, and 195Pt) give important information on compound properties and structure. Also the NMR of paramagnetic species can result in important structural information. Proton NMR is also important because the light hydrogen nucleus is not easily detected by X-ray crystallography. o Infrared spectroscopy: Mostly for absorptions from carbonyl ligands o Electron-nuclear double resonance (ENDOR) spectroscopy o Mssbauer spectroscopy o Electron-spin resonance: ESR (or EPR) allows for the measurement of the environment of paramagnetic metal centres. Electrochemistry: Cyclic voltammetry and related techniques probe the redox characteristics of compounds.譯文：第一課無機(jī)化學(xué)無機(jī)化學(xué)是一門涉及化學(xué)性質(zhì)和無機(jī)化合物反應(yīng)的化學(xué)學(xué)科分支。無機(jī)化學(xué)包括了所有除了那些基于鏈或環(huán)的碳原子的被稱為有機(jī)化合物，并在有機(jī)化合物的獨(dú)立標(biāo)題下研究有機(jī)化學(xué)的化合物。兩學(xué)科之間的區(qū)別并不是絕對(duì)的,兩者之間有許多重疊,最重要的是在有機(jī)金屬化學(xué)的分支學(xué)科上。1主要概念無機(jī)化合物主要是鹽，它是通過陰、陽離子通過離子鍵鍵合形成。例如：陽離子鈉Na+和鎂Mg2+分別與陰離子氧O2-和氯Cl-形成化合物。鹽都是電中性的,如離子化合物氧化鈉Na2O或氯化鎂MgCl2。這些離子的電性可以由他們的氧化態(tài)和易于形成可以從他們母體元素中的電離電位和電子親和力推斷出來的來描述。一類重要的無機(jī)化合物是氧化物,碳酸鹽、硫酸鹽和鹵化物。許多無機(jī)化合物都具有很高的熔點(diǎn)。固態(tài)無機(jī)鹽是典型的不良導(dǎo)體。另一個(gè)重要性質(zhì)是他們?cè)谒械娜芙舛群腿菀捉Y(jié)晶。有些鹽(例如NaCl)極易溶于水,另一些(例如 二氧化硅)是不易溶于水的。最簡(jiǎn)單的無機(jī)反應(yīng)是復(fù)分解反應(yīng)，即在兩種鹽的混合物中，離子相互交換但不發(fā)生電荷及化合價(jià)的改變。在氧化還原反應(yīng)中，氧化劑的化合價(jià)降低，還原劑的化合價(jià)升高，最終的結(jié)果是發(fā)生了。交換電子也可以間接發(fā)生，例如電池電化學(xué)中一個(gè)很重要的概念。在酸堿化學(xué)中，反應(yīng)物包含氫原子的反應(yīng)可以通過交換質(zhì)子發(fā)生。更廣泛的定義就是：在任何化學(xué)種類里能結(jié)合電子對(duì)的被稱為路易斯酸,相反的，任何提供電子對(duì)的分子被稱為路易斯堿。在精細(xì)酸堿反應(yīng)中,軟硬酸堿理論考慮到離子的極化性和離子大小。無機(jī)化合物存在于天然礦物質(zhì)中。例如土壤和黃鐵礦中含有硫化亞鐵，石膏中含有硫酸鈣。無機(jī)化合物應(yīng)用于多個(gè)方面：作為生物大分子，作為電解液(氯化鈉)，作為儲(chǔ)能物(ATP)或作為結(jié)構(gòu)骨架（DNA骨架中的多磷酸鹽)。最重要的人工合成的無機(jī)化合物是通過哈伯合成氨法合成的，用于土壤施肥的亞硝酸鹽銨。無機(jī)化合物可以用來合成催化劑如五氧化二釩和三氯化鈦或有機(jī)化學(xué)試劑如鋁鋰氫化物。無機(jī)化學(xué)分為有機(jī)金屬化學(xué)、簇化學(xué)和生物無機(jī)化學(xué)。這些領(lǐng)域在無機(jī)化學(xué)的研究中是非常活躍的，旨在研究新的催化劑、超導(dǎo)體和治療方法。2定性無機(jī)化學(xué)定性無機(jī)化學(xué)主要講的是無機(jī)化合物基于其性質(zhì)的分類。一部分是根據(jù)化合物中重元素在元素周期表中的位置分類的，一部分是根據(jù)他們的結(jié)構(gòu)的相似性來分類化合物的。當(dāng)學(xué)習(xí)無機(jī)化合物時(shí)，經(jīng)常面臨不同種類的無機(jī)化學(xué)(有機(jī)金屬化合物的特點(diǎn)是配位化學(xué)，顯示出了有趣的固態(tài)性質(zhì))。不同的分類:配位化合物經(jīng)典配位化合物的特征是金屬結(jié)合位于由主族原子形成的配位體上的孤對(duì)電子，例如水、NH3、Cl-和 CN-。在現(xiàn)代配位化學(xué)中，幾乎所有的有機(jī)和無機(jī)化合物都可以作為配位體。前面所說的“金屬”往往是族的金屬，也可以是過渡鑭系和過渡錒系的金屬，但從某種角度看,所有化合物都可以被描述為配位復(fù)合體。 配位復(fù)合物的立體化學(xué)是相當(dāng)豐富的。由溫納斯分離出的兩種對(duì)映體Co(OH)2Co(NH3)4)36+,早期證明了手性不是有機(jī)化合物所固有的。在這個(gè)專業(yè)，典型的主題就是超分子配位化學(xué)。例如:Co(EDTA),Co(NH3)63 +,TiCl4(THF)2。主族化合物這些種類的特征元素是元素周期表中12族和1318族(不含氫)的元素。由于他們常有相似的反應(yīng)活性,第3族元素（鈧，釔，鑭)和第12族(鋅、鎘，汞)也通常包括在內(nèi)。主族化合物從化學(xué)發(fā)展的開端就被人們所熟知，如化學(xué)元素硫和可以蒸餾的白磷。拉瓦錫和普里斯特利對(duì)氧的實(shí)驗(yàn)不僅找到了一種重要的雙原子氣體，而且發(fā)現(xiàn)了通過化學(xué)計(jì)量數(shù)之比來描述化合物和化學(xué)反應(yīng)的方法。早在1900年，卡爾博世和弗里茨哈伯用鐵做催化劑合成氨的實(shí)踐深深地影響了人類，展示出了無機(jī)化學(xué)合成的重要性。典型的主族元素化合物有氧化二氮，二氧化硅和四氯化錫。許多主族化合物也可以歸類為有機(jī)金屬化合物，因?yàn)樗麄兒袡C(jī)基團(tuán)如甲硼烷。主族化合物也存在于自然界中，例如DNA中含有磷酸鹽，因此可以歸為生物無機(jī)化合物。相反地,有機(jī)缺氫配位化合物可以歸類為“無機(jī)”,例如,富勒烯,二倍碳氧化物。例子: 氮化硫，乙硼烷， ,硅酮和碳六十。 過渡金屬化合物 含有411族金屬的化合物是過渡金屬化合物。含有312族金屬的化合物有時(shí)也被歸為過渡金屬化合物，但通常他們屬于主族化合物一類。過渡金屬化合物展現(xiàn)出豐富的配位化學(xué),從四面體的鈦到平面的鎳，再