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Iso Compounds: Structure, Properties and Uses

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Properties of Iso Compounds

We use the prefix iso to identify an organic compound that has all carbon atoms, except one, arranged in a continuous chain. So, we use this phrase whenever a molecule has a single branch. The carbon chain splits off at this point.

The term "iso" can also refer to a molecule that is a constitutional isomer of another molecule having a common (or trivial) name.

Structure and Bonding of Iso Compounds

Iso is a prefix that describes an organic molecule with all carbon atoms except one that forms a continuous chain. As a result, we use this phrase when there is just one branch in the molecule. This branch is found at the very end of the carbon chain.

This branch is known as the "terminal isopropyl group." When a methyl group is connected to the second carbon of a carbon chain, we use the prefix iso to designate the molecule. Isopropyl alcohol, for example. This prefix can identify compounds with at least four carbon atoms.

Two crystals are considered to be isostructural if they have the same structure but not necessarily the same cell v or chemical composition and if the variability in the atomic coordinates is 'similar' to the variability in the cell dimensions and chemical composition. Calcite CaCO3, sodium nitrate NaNO3, and iron borate FeBO3 are all isostructural. Isostructural series, polymorphs, and phase transitions are other terms for the same thing. The terms isotypic and isostructural are interchangeable.

Nomenclature of Iso Compounds

Some branched alkanes have popular names that are still used today. Prefixes such as iso-, sec-, tert-, and neo- are used in these common names. 2-methyl alkanes are usually prefixed with the word iso-, which stands for isomer. In other words, if a methyl group is found on the second carbon in a carbon chain, the prefix iso- might be used. The prefix shows the total number of carbons and will be placed before the alkane name.

Examples: Isopentane is the same as 2-methylbutane, whereas isobutane is the same as 2-methylpropane.

Odour and Toxicity

Isopropanol, like other hazardous alcohols, is rapidly absorbed, with about 80% absorbed within 30 minutes of administration. Approximately 80% of the isopropanol ingested is metabolised by the liver via first-order kinetics and converted to acetone by the enzyme alcohol dehydrogenase. Isopropanol blood levels typically peak between 30 minutes and 3 hours after intake, with a half-life of 3 to 7 hours.

When isopropanol is co-ingested with ethanol, its half-life increases because ethanol has a stronger affinity for alcohol dehydrogenase than isopropanol, acetone, on the other hand, has a half-life of 22 hours and is mostly eliminated by the kidneys.

Isopropanol, often known as isopropyl alcohol, is a clear, colourless liquid with an odour similar to acetone. It is a commercially accessible substance mostly found in rubbing alcohol and hand sanitisers as a 70% solution.

Isopropanol, unlike other hazardous alcohols, seldom causes mortality and is linked with ketosis without acidosis. Isopropanol ingestions are routinely treated with supportive care, and ingestions are seldom fatal.

Synthesis of Iso Compounds

Chemical compounds are atoms from various elements held together by chemical bonds. Chemical synthesis generally entails breaking existing bonds and forming new ones.

In materials science, isoindoline has found widespread use. Isoindole-containing BODIPY dyes are extremely fluorescent compounds widely employed in various scientific applications. Most elements of the periodic table form coordination complexes with phthalocyanines, which are metal-containing cyclic tetramers of isoindole.

Important Questions

1. Why is isopropyl also known as sec-propyl, yet t-butyl is not known as neo-butyl?

At least five C atoms must be present when one C atom is connected with four C atoms. As a result, butyl cannot be neo. When a methyl group is added to the second position of isopropyl, it is transformed into t-butyl. Isopropyl alcohol is what this is.

2. Why is isopropyl also known as sec-propyl?

Since the functional group in isopropyl is linked to the second position, isopropyl is essentially 2-propyl. Butyl groups have four carbon atoms. T-butyl has four carbon atoms, one of which is bound to the other three.


2-methyl alkanes are usually prefixed with the word iso-, which stands for isomer. In other words, if a methyl group is found on the second carbon in a carbon chain, the prefix iso- might be used.

In organic chemistry, iso refers to an organic molecule that contains all carbon atoms except one in a continuous chain. This prefix is used to identify a chemical with a single branch in its carbon chain. In organic chemistry, the word Sec refers to the attachment of a secondary carbon.

Last updated date: 27th Sep 2023
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FAQs on Iso Compounds: Structure, Properties and Uses

1. When naming organic compounds, do we use the prefixes iso, neo, tert, and sec?

Iso: one carbon branching at the chain's second final carbon.

Neo: two single-carbon chains, one at either end of the chain.

Sec: connection at the chain's secondary carbon

Tert: chain connection at the tertiary carbon

When all but two carbons form a continuous chain, the prefix "neo" is used. When the functional group is attached to a secondary carbon, the prefix "sec" or "s" is used. When the functional group is attached to a tertiary carbon, the prefix "tert" or "t" is used.

2. Is IsoOctane a possibility?

The chemical molecule 2,2,4-trimethylpentane, sometimes known as iso-octane or iso-octane, has the formula (CH3)3CCH2CH(CH3)2. It is one of the numerous octane isomers (C8H18). This isomer corresponds to the conventional octane rating of 100. (the zero point is n-heptane). The use and production of isooctane are anticipated to increase sharply shortly. The traditional method for producing isooctane comprises dimerizing isobutene in a fixed bed reactor with a supported acid catalyst, then hydrogenating the result in a continuously stirred tank reactor using hydrogenation catalysts.

3. Which of the following compounds is categorised as an ether?

The more complicated group is called the root name in systematic (IUPAC) nomenclature for ethers, with the oxygen atom and the smaller group identified as an alkoxy substituent. Ethoxyethane (diethyl ether), methoxyethane (methyl ethyl ether), 2-methoxy-2-methylpropane (MTBE), and phenoxybenzene are other examples (diphenyl ether). A functional group must have two non-carbonyl carbons and an oxygen atom to be referred to as ether. When a carbon atom is double-bonded to oxygen, it is referred to as a "carbonyl."