Difference Between Functional Group and Homologous Series

Thekey differencebetween functional group and homologous series is thatfunctional group is a moiety of a chemical compound that is responsible for the reactivity of that chemical compound whereas homologous series is a sequence of chemical compounds having the similar functional group and similar chemical reactivity。

术语函数组和同源系列是两个相关术语。这是因为根据化合物的官能团形成同源序列。

内容

1.Overview and Key Difference
2.What is a Functional Group
3.What is a Homologous Series
4.并排比较 - 功能组与表格形式的同源系列
5.概括

What is Functional Group?

Functional groups are specific substituents that occur within a molecule and are responsible for the characteristic chemical reactions those molecules undergo. For example, if the functional group is the same for two molecules that have different chemical structures, the two molecules will undergo similar types of reactions, no matter the size of the molecules. Generally, functional groups are very important in different aspects; in identifying unknown molecules, in determining end products of reactions, in chemical synthesis reactions for the designing and synthesis of new compounds, etc.

Difference Between Functional Group and Homologous Series

Figure 01: Functional Groups in Different Organic Compounds

通常，官能团通过分子通过共价化学键。在聚合物中，官能团连接到碳原子的非极性核心上，从而使聚合物具有特定的特征。但是，官能团有时是充电的化学物种。即羧酸盐离子组。这使得分子成为多原子离子。另外，在坐标复合物中附着在中央金属原子上的官能团称为配体。一些功能组的常见示例包括羟group,carbonylgroup,醛group,ketonegroup, carboxyl group, etc.

What is a Homologous Series?

A homologous series is a sequence of chemical compounds having the same functional groups and thus, the same chemical reactivity. This term is used mainly in the field of organic chemistry where chemical compounds can be either branched or unbranched structures. A homologous series can form according to the length of a carbon chain or according to the number of monomer units in a homopolymer as well. For example, a homologous series of straight-chain alkanes begin with methane, ethane propane, butane and pentane.

图02：沸点逐渐变化

Typically, the members of a homologous series contain a fixed set of functional groups that give these molecules similar chemical and physical properties. E.g. the primary straight chain alcohols have a hydroxyl at the end of the carbon chain. The properties of the homologous series gradually change along with the series, and these changes can often be explained by slight differences in molecular size and mass. However, if we cannot arrange the members of the series according to a linear order depending on a single parameter, the compounds collection is called a chemical family or a class of homologous compounds, not a series.

What is the Difference Between Functional Group and Homologous Series?

术语函数组和同源系列是两个相关术语。The key difference between functional group and homologous series is that functional group is a moiety of a chemical compound that is responsible for the reactivity of that chemical compound whereas homologous series is a sequence of chemical compounds having the similar functional group and thus, similar chemical reactivity.

下面的信息图介绍了功能组和同源系列之间差异的更多细节。

概括– Functional Group vs Homologous Series

A homologous series forms according to the functional groups of chemical compounds. Therefore, the key difference between functional group and homologous series is that functional group is a moiety of a chemical compound that is responsible for the reactivity of that chemical compound whereas homologous series is a sequence of chemical compounds having the similar functional group and thus, similar chemical reactivity.