User:Milton Beychok/Sandbox: Difference between revisions

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==Characterization of inorganic compounds==
==Types of inorganic compounds ==
Because 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 point]]s, [[solubility]], and [[acidity]].  With the advent of [[Quantum mechanics|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 [[Ultra-violet photoelectron spectroscopy|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 structure]]s.
==Typical inorganic chemical reactions==
* [[Dual polarisation interferometer]]: This technique measures the [[conformational isomerism|conformation]] and [[conformational change]] of molecules.
 
* Various forms of [[spectroscopy]]
 
** [[Ultraviolet-visible spectroscopy]]: Historically, this has been an important tool, since many inorganic compounds are strongly colored
==Analysis and characterization of  inorganic compounds==
** [[NMR spectroscopy]]: Besides <sup>1</sup>[[Hydrogen|H]] and <sup>13</sup>[[Carbon|C]] many other "good" NMR nuclei (e.g. <sup>11</sup>[[Boron|B]], <sup>19</sup>[[Fluorine|F]], <sup>31</sup>[[Phosphorus|P]], and <sup>195</sup>[[Platinum|Pt]]) 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.
 
** [[Infrared spectroscopy]]: Mostly for absorptions from [[:category:carbonyl complexes|carbonyl ligands]]
The number of known chemical elements that occur naturally on [[Earth]] is 94 and the number of diverse inorganic chemical compounds derived by combinations of those elements is virtually innumerable. The characterization of those compounds includes the [[measurement]] of chemical and physical  properties such as [[boiling point]]s, [[melting point]]s, [[density (chemistry)|density]], [[solubility]], [[refractive index]] and the  [[pH]] and [[electrical conductivity]] of solutions.
** [[Electron nuclear double resonance]] (ENDOR) spectroscopy
 
**[[Mössbauer spectroscopy]]
The  techniques of qualitative and quantitative [[analytical chemistry]] can provide the composition of a chemical compound in terms of its constituent chemical elements and can thus determine the [[chemical formula]] of  a compound.
** [[Electron-spin resonance]]: ESR (or EPR) allows for the measurement of the environment of [[paramagnetic]] metal centres.
 
* [[Electrochemical|Electrochemistry]]: [[Cyclic voltammetry]] and related techniques probe the redox characteristics of compounds.
Modern laboratory equipment and techniques can provide many more details for characterizing chemical compounds. Some of the more commonly used modern techniques are:
 
* [[Chromatography]]: A process for separating mixtures into their component constituents.
* [[X-ray diffraction]] or [[X-ray crystallography]]: A technique that determines three-dimensional arrangement of atoms within a molecule.
* [[Spectrometry]] or qualitative [[Spectroscopy]]: A technique for the identification of substances through the [[electromagnetic spectrum]] emitted from or absorbed by them.
* [[Voltammetry]]: An [[Electrochemistryl|electrochemical]] method for studying a chemical substance by measuring the [[Voltage|electrical potential ]] and/or current (amperes) in an [[electrochemical cell]] containing the substance.

Revision as of 14:46, 5 October 2010

Types of inorganic compounds

Typical inorganic chemical reactions

Analysis and characterization of inorganic compounds

The number of known chemical elements that occur naturally on Earth is 94 and the number of diverse inorganic chemical compounds derived by combinations of those elements is virtually innumerable. The characterization of those compounds includes the measurement of chemical and physical properties such as boiling points, melting points, density, solubility, refractive index and the pH and electrical conductivity of solutions.

The techniques of qualitative and quantitative analytical chemistry can provide the composition of a chemical compound in terms of its constituent chemical elements and can thus determine the chemical formula of a compound.

Modern laboratory equipment and techniques can provide many more details for characterizing chemical compounds. Some of the more commonly used modern techniques are:

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