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Definition

 

Activation energy

The amount by which the energy of reactants must be raised for reaction to take place

 

Analgesic

A substance with pain-relieving properties

 

Aromatic

Compounds based on the “benzene ring”

 

Atom economy

The proportion of reactant atoms that appear in the desired product

 

Autoclave

Apparatus used for small-scale reactions in a contained environment, usually at high pressure

 

Biocatalysis

Catalysed reactions where the catalyst is an enzyme

 

Biotransformation

Chemical reaction carried out using biological catalysts

 

Candida rugosa

A fungus used in biocatalysis

 

Carbocation

(“Carbo – cation”, not “carbocashun”!) A positive ion formed from an organic molecule

 

Cat cracker

“Catalytic cracker” – industrial scale equipment used to break large alkane molecules from fractional distillation of oil into smaller molecules

 

Chemical promoter

A substance which, though not itself a catalyst, improves the effectiveness of the catalyst by chemical means

 

Chiral

Term used to describe molecules that contain a carbon atom that is surrounded by four different groups, allowing for isomers that are mirror-images (leading to optical isomerism)

 

Co-catalyst

A second catalyst used in conjunction with another

 

Co-monomer

Monomer molecules used in addition to main monomer when making a polymer (introduces controlled branching)

 

Cracking

Breaking large alkane molecules from heavier oil fractions into smaller ones

 

Creep

Polymer chains sliding over one another in a plastic, leading to a change in dimensions

  Diffraction An interference effect that leads to the scattering of beams of electromagnetic radiation and small particles (like electrons) in specific directions - used to help determine structure
 

Enantiomers

Two mirror-image molecules

 

Envirocats

A group of catalysts using clay supports

 

Enzyme

A catalyst of biological origin

 

Ferrocene

The first of the metallocenes, transition metal complexes consisting of a metal atom “sandwiched” between two 5-membered rings

 

Fuel Cell

Electrochemical cell used to generate electricity from fuels

 

hdpe

High Density Poly(ethene)

 

Heterogeneous catalysis

Catalysed reactions in which the catalyst and reactants are in different phases (solid, liquid or gas)

 

Homogeneous catalysis

Catalysed reactions in which the catalyst and reactants are in the same phase (solid, liquid or gas)

  IR Spectrum Infra-red radiation can cause a molecule to vibrate, absorbing energy, and the frequencies at which this happens is different for each substance. A spectrum can be produced showing the frequencies at which absorption occurs, effectively a fingerprint for the material.
 

Isomerism

The characteristic of substances that have the same formula, but different structures

 

Kaminsky

Walter Kaminsky developed catalysts based on metallocenes

 

Kevlar

A nylon-based fibre with exceptional strength – used to make bullet-proof vests, tyres, heat resistant fabrics

 

ldpe

Low density poly(ethene)

 

Lewis acid

A substance that is an electron-pair acceptor

 

lldpe

Linear low density poly(ethene)

 

MAO

Methylalumoxane – formed during activation of a metallocene catalyst for  the production of poly(ethene)

 

Metallocene

Transition metal complexes consisting of metal atoms “sandwiched” between 5-membered rings

 

Montmorillonite

A type of clay used as catalyst support in Friedel-Crafts alkylation

 

Nanotechnology

Technology that is on a molecular (or strictly nanometre) scale

 

Natta

Developer of organo-metallic catalysts for production of plastics – shared Nobel Prize with Ziegler

 

Optical isomerism

Isomerism as a result of a molecule existing in two mirror-image forms (which affect polarised light differently).  The two isomers are referred to as the L- and D- isomers, or alternatively as the (R) and (S) forms

 

Organometallic

Organic compounds that also include one or more metal atoms

 

PET

“Polyethylene terephthalate” (polyethene benzene – 1,4- dicarboxylate) – used to make lightweight plastic bottles

 

Polyethylene

Poly(ethene) Note that Polythene is an ICI trade name

 

Promoter

A substance which, though not itself a catalyst, improves the effectiveness of the catalyst – promoters may act chemically or physically

 

Protecting groups

Groups of atoms that are placed temporarily on parts of a molecule which need to be protected from a reagent to be used in one of the synthetic steps needed to make the final product . These protecting groups are removed afterwards.

 

Racemic mixture

An equal mixture of the two optical isomers of a compound, being therefore optically inactive

 

Racemisation

The process of producing an equal mixture of the two optical isomers of a compound

 

Recombinant DNA techniques

 These are a variety of techniques used to analyse and manipulate DNA. They include methods to modify genes and construct new genes. The techniques also include ways to express new and modified genes to yield protein products.

 

Reforming

The process of synthesising a suitable material from another less suitable one

 

Rhodococcus rhodochrous

A bacterium used to provide the enzymes used in the biocatalytic manufacture of Propeneamide.  This bacterium is able to use organic substances as its sole source of carbon for growth

 

Sintering

The fusing of individual solid particles caused by heating.

  Spectroscopy Methods for analysing materials based on how the reflection or transmission of radiation (eg light, IR etc) is affected by the material
 

Stereo selective

Reacting mainly with only one optical isomer

 

Stoichiometric

In the proportions indicated by the chemical equation

 

Structural promoter

A substance which, though not itself a catalyst, improves the effectiveness of the catalyst by providing a suitable structure

 

Supercritical CO2

Carbon dioxide at a temperature and pressure such that distinct liquid and gas phases do not occur

 

TAED

Tetraacetyl ethylenediamine is used in some washing powder detergents to enable peroxide-based bleaches to work at lower temperatures

 

titanocene

A metallocene compound containing the metal titanium

 

uhmwpe

Ultra High Molecular Weight Poly(ethene)

 

Zeolite

A group of aluminosilicate materials, some of which occur in nature. They are widely used as catalysts and as catalyst supports.

 

Ziegler

Developer of organo-metallic catalysts (known as Ziegler Catalysts) for production of plastics – shared Nobel Prize with Natta

 

Zirconocene

A metallocene compound containing the metal zirconium