The IUPAC designations for aldehydes and ketones follow the well-known pattern of picking the longest chain of carbon atoms that includes the functional group as the parent alkane.

• We demonstrate the aldehyde group by altering the parent alkane's suffix -e to -al (as shown in the image attached).

Because an aldehyde's carbonyl group may only exist at the end of a parent chain and numbering must begin with it as carbon-1, its position is obvious; there is no need to use a number to find it.

• The presence of a carbon-carbon double or triple bond is indicated by the infix -en- or -yn- in unsaturated aldehydes.

• The placement of the group corresponding to the infix, as with other compounds with both an infix and a suffix, is the same as in other molecules with both an infix and a suffix.

Ketones are designated in the IUPAC system by selecting the longest chain that includes the carbonyl group as the parent alkane and then expressing its presence by altering the suffix from -e to -one (as show in the image attached).

• The parent chain is numbered in the direction of the carbonyl carbon with the lower number.

• The common terms acetone, acetophenone, and benzophenone are still used by the IUPAC system.

  • The term order of precedence of functions refers to a ranking of functional groups in order of priority for the purposes of IUPAC nomenclature.

Ketones are designated in the IUPAC system by selecting the longest chain that includes the carbonyl group as the parent alkane and then expressing its presence by altering the suffix from -e to -one (as shown in the image attached).

The parent chain is numbered in the direction of the carbonyl carbon with the lower number.

The common terms acetone, acetophenone, and benzophenone are still used by the IUPAC system.

• Because oxygen has a higher electronegative potential than carbon (3.5 vs. 2.5), a carbon-oxygen double bond is polar, with oxygen having a partial negative charge and carbon having a partial positive charge.

• Furthermore, the resonance structure depicted on the right highlights the reactivity of carbonyl oxygen as a Lewis base and carbonyl carbon as a Lewis acid. A carbonyl group has a bond dipole moment of 2.3 D.

The image attached shows an electrostatic potential map for acetone.

• Note the large negative charge on oxygen (red) and the positive charges (blue) on the three carbons.

Diethyl ether and pentane have the lowest boiling points among the chemicals listed in the image attached.

• Diethyl ether is a polar molecule, but due to steric hindrance, its molecules only have modest dipole-dipole interactions (as shown in the image attached).

• Butanal and 2-butanone are both polar compounds with higher boiling temperatures than pentane and diethyl ether due to intermolecular interaction between their carbonyl groups.

• Alcohols (as shown in the image attached) and carboxylic acids are polar molecules that may form the strongest intermolecular connection, hydrogen bonding.

The boiling temperatures of 1-butanol and propanoic acid are substantially higher than those of butanal and 2-butanone, which cannot form hydrogen bonds between their molecules.

• Because the oxygen atoms in aldehydes and ketones' carbonyl groups operate as hydrogen bond acceptors with water, low-molecular-weight aldehydes and ketones are more soluble in water than nonpolar molecules of equivalent molecular weight.

The image attached shows the boiling temperatures and water solubilities of numerous low-molecular-weight aldehydes and ketones.

• The term Nucleophilic acyl addition refers to a characteristic reaction mechanism of carbonylcontaining compounds such as aldehydes and ketones in which a nucleophile makes a new bond to the electrophilic carbonyl carbon atom

One of the most typical carbonyl group reaction motifs is the addition of a nucleophile to generate a tetrahedral carbonyl addition complex.

• Because of its considerable partial positive charge and the capacity to accommodate a new bond via the conversion of the p bond to a lone pair on oxygen of the tetrahedral carbonyl addition complex, the carbonyl carbon atom is extremely electrophilic.

• These reactions are known as nucleophilic acyl additions.

• To underline the existence of its unshared pair of electrons, the nucleophilic reagent is denoted as Nu:2 in the following typical reaction.

Take note of how the carbonyl group's p bond breaks when the nucleophile hits, altering the hybridization state of the carbon atom while keeping four bonds.

Carbonyl molecules, such as aldehydes and ketones, are involved in a broad range of significant reactions, the majority of which involve nucleophilic acyl addition.

• Because virtually all of the processes can be characterized as one of the four mechanistic elements initially outlined, the mechanisms for these reactions are identical.

When deciding which of the four mechanisms to start, consider whether an acid or a strong base is present.

• If there is a nucleophile but no acid or base, the reaction process will start with the nucleophile attacking the electrophilic carbonyl carbon atom (forming a new bond between a nucleophile and an electrophile).

As the nucleophile adds, the carbonyl's p bond splits. If an acid is present, the proton will add to the carbonyl oxygen atom (add a proton), increasing the electrophilicity of the carbonyl group.

• In these circumstances, the next step is for a nucleophile to attack the carbonyl carbon atom.

• Carbonyl compounds undergo a third distinctive reaction (take a proton away) in the presence of a strong base to generate a highly significant species known as an enolate anion.

A new chiral center is frequently formed as a tetrahedral result of nucleophile addition to a carbonyl.

• If none of the initial components are chiral, the nucleophile will approach the carbonyl with equal probability from either side.