What Is Inorganic Chemistry?
Inorganic chemistry is concerned with the properties and behavior of inorganic compounds, which include metals, minerals, and organometallic compounds. While organic chemistry is defined as the study of carbon-containing compounds and inorganic chemistry is the study of the remaining subset of compounds other than organic compounds, there is overlap between the two fields (such as organometallic compounds, which usually contain a metal or metalloid bonded directly to carbon).
Where Is Inorganic Chemistry Used?
Inorganic compounds are used as catalysts, pigments, coatings, surfactants, medicines, fuels, and more. They often have high melting points and specific high or low electrical conductivity properties, which make them useful for specific purposes. For example:
- Ammonia is a nitrogen source in fertilizer, and it is one of the major inorganic chemicals used in the production of nylons, fibers, plastics, polyurethanes (used in tough chemical-resistant coatings, adhesives, and foams), hydrazine (used in jet and rocket fuels), and explosives.
- Chlorine is used in the manufacture of polyvinyl chloride (used for pipes, clothing, furniture etc.), agrochemicals (e.g., fertilizer, insecticide, or soil treatment), and pharmaceuticals, as well as chemicals for water treatment and sterilization.
- Titanium dioxide is the naturally occurring oxide of titanium, which is used as a white powder pigment in paints, coatings, plastics, paper, inks, fibers, food, and cosmetics. Titanium dioxide also has good ultraviolet light resistance properties, and there is a growing demand for its use in photocatalysts.
Inorganic chemistry is a highly practical science—traditionally, a nation’s economy was evaluated by their production of sulfuric acid because it is one of the more important elements used as an industrial raw material.
Inorganic chemists are employed in fields ranging from mining to microchips. Their work is based on understanding the behavior and the analogues for inorganic elements and how these materials can be modified, separated, and used. It includes developing methods to recover metals from waste streams; employment as analytical chemists specializing in the analysis of mined ores; and performing research on the use of inorganic chemicals for treating soil.
Many inorganic chemists work in industry, but they also work in academic institutions and in government labs. Inorganic chemists who work in government say their time is increasingly spent writing grant proposals and competing for research money.
Inorganic chemists compare their jobs to those of materials scientists and physicists. The common focus is on the exploration of the relationship between physical properties and functions, but an inorganic chemist is more concerned with these properties at the molecular level.
Industries that Hire Inorganic Chemists
Inorganic chemistry is a highly practical area of science used in many industries, including:
Environmental chemistry uses inorganic chemistry to understand how the uncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. They also identify the effects of additives, such as fertilizers, on natural processes. The U.S. Environmental Protection Agency and other agencies detect and identify the nature and source of pollutants.
Companies that focus in environmental science include CH2M Hill, Bechtel, Veolia, URS Corporation, Black & Veatch, Tetra Tech, Energy Solutions, and government agencies as the U.S. Environmental Protection Agency (EPA). These companies study the chemical and biochemical phenomena that occur in natural places. They use atmospheric, aquatic, and soil chemistry, as well as analytical chemistry.
Fibers and Plastics
Fibers are materials that are continuous filaments or discrete elongated pieces, similar to lengths of thread. They are important for a variety of applications, including holding tissues together in both plants and animals. There are many different kinds of fibers including textile fiber, natural fibers, and synthetic or human-made fibers such as cellulose, mineral, polymer, and microfibers. Fibers can be spun into filaments, string, or rope; used as a component of composite material; or matted into sheets to make products such as paper. Fibers are often used in the manufacture of other materials. The strongest engineering materials are generally made as fibers, for example, carbon fiber and ultra-high-molecular-weight polyethylene. Synthetic fibers can often be produced cheaply and in large amounts as compared to natural fibers, but natural fibers have benefits some applications, especially for clothing.
Plastic material is any of a wide range of synthetic or semisynthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass and may contain other substances to improve performance and/or reduce production costs. Monomers of plastic are either natural or synthetic organic compounds.
Thermoplastics are plastics that do not undergo chemical change in their composition when heated and therefore can be molded again and again; examples are polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polytetrafluoroethylene. The raw materials needed to make most of these plastics come from petroleum and natural gas.
Because of their relatively low cost, ease of manufacture, versatility, and imperviousness to water, plastics are used in a wide range of products, from paper clips to spaceships. However, these same properties make them persist beyond their usefulness, so much current work is focused on making photodegradable or other more environmentally friendly versions.
Chemistry and material science allows the production of inorganic electronics with highly ordered layers and interfaces that organic and polymer materials cannot provide. Precise control of surface composition results in microchips with specific, desired properties.
An integrated circuit or monolithic integrated circuit (also referred to as IC, chip, or microchip) is an electronic circuit manufactured by the patterned deposition (or diffusion) of trace elements into the surface of a thin substrate of semiconductor material. Additional materials are deposited and patterned to form interconnections between semiconductor devices.
Integrated circuits are used in virtually all electronic equipment today and have revolutionized society. Computers, cell phones, and other digital appliances are now inextricable parts of the structure of modern societies, made possible by the low cost of production of integrated circuits.
Integrated circuits are also being developed for sensoric applications in medical implants and other bioelectronic devices. These environments require special sealing strategies to avoid corrosion or biodegradation of the exposed semiconductor materials.
Mining, Ore, and Metals
Mining involves the extraction of valuable minerals or other geological materials from the earth or from an ore body, vein, or seam. Materials recovered by mining can include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock salt, and potash. Any material that cannot be grown through agricultural processes or created in a laboratory or factory comes from mining. In the wider sense, mining comprises extraction of any nonrenewable resource (e.g., petroleum, natural gas, or even water) for human use.
Paint, Pigment, and Coatings
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. Pigments are classified as either organic (derived from plant or animal sources) or inorganic (derived from salts or metallic oxides).
Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food, and other materials. Most pigments used in manufacturing and the visual arts are dry inorganic colorants, usually ground into a fine powder. This powder is added to a vehicle (or binder), which is a relatively neutral or colorless material that suspends the pigment and gives the paint its adhesion.
Examples of companies that focus in paint, pigment, and coatings are Continental Chemical, Lintech International, Shepherd Chemical Company, DuPont, The Valspar Corporation, and Glidden Paints (A division of PPG Industries).
Chemists in the Field
Voices of Inorganic Chemistry
Interviews with prominent inorganic chemists.
ACS Division of Inorganic Chemistry
The Division of Inorganic Chemistry (DIC) represents a diverse body of scientists who come together to understand and promote the richness of the chemistry of the elements. The division focuses its work on five areas:
- Organometallic Chemistry. Includes the synthesis, characterization, and reactivity of main group, transition metal, and rare earth organometallic compounds, as well as the applications of such compounds in organic synthesis, inorganic synthesis, and catalysis.
- Bioinorganic Chemistry. Includes all aspects of the chemistry of the metallic elements and small inorganic molecules in biological systems.
- Solid-State and Materials Chemistry. Includes the synthesis, characterization, and physical and chemical properties of solids that contain metallic and/or main group elements.
- Coordination Chemistry. Includes the synthesis, characterization, and physical and chemical properties of classical coordination compounds.
- Nanoscience. Includes the synthesis, characterization, and physical and chemical properties of nanostructured materials (inorganic nanocrystals, inorganic–organic hybrid materials, etc.).