ORGANIC CHEMISTRY: CONCEPTS AND
APPLICATIONS
CHAPTER 1
Bonding and Structure of Organic
Compounds
1.1 Introduction
The word “organic” was first used to describe compounds that were derived
from plants or animals, but this term was later used to describe compounds
that contain mostly carbon and hydrogen atoms. Today, the term organic is
loosely used to describe food that is produced without the use of pesticides,
hormones, antibiotics, or fertilizers.
In organic chemistry, we will carry out a detailed study of the composition,
properties, and reactions of compounds that contain primarily carbon and
hydrogen atoms, also known as organic compounds. Even though many
organic compounds contain only carbon and hydrogen atoms, a large
percentage contains other atoms, such as oxygen, nitrogen, sulfur, as well as
halogens; these atoms are referred to as heteroatoms. Atoms other than
carbon and hydrogen that are present in organic compounds are called
heteroatoms.
Prior to the start of the nineteenth century, chemists were familiar with
inorganic compounds; for example, it was known that ammonium cyanate,
an inorganic compound, could be easily made by the exchange reaction
shown in reaction (fig 1:1)
,Even though organic compounds were known, similar reactions that could
be used for their synthesis were not known. Instead, organic compounds
were obtained primarily from natural sources, such as extraction from
plants and other natural sources. As early as 1828, a medical doctor,
Friedrich Wöhler, synthesized urea, a known organic compound. The
synthesis of urea was accomplished by heating ammonium cyanate (an
inorganic compound), as shown by the reaction (fig1:2)
This was a major discovery that initiated the era of organic chemistry. For
the first time, an organic compound could be synthesized and these types of
compounds did not have to be obtained naturally. In the early 1800s, just
about all compounds that were used for different reasons, mostly medical,
were obtained from natural sources. Today, a large percentage of organic
compounds, including urea, which is a major component of fertilizer,
adhesives, and resins, are synthesized and are not obtained naturally.
, You may be wondering where are the carbon and hydrogen atoms in these
compounds since they are not shown in the structure, except for the first
structure, which shows two representations of N,N‐diethyl‐3‐
methylbenzamide (DEET). You will learn later in this chapter that at each
intersection in the structure, there are carbon and hydrogen atoms or just
carbon atoms. DEET contains carbon, hydrogen, oxygen, and nitrogen
atoms. Ibuprofen, a painkiller, contains carbon, hydrogen, and oxygen
atoms. The artificial sweetener, saccharin, contains carbon, hydrogen,
oxygen, nitrogen, and sulfur atoms. Dichlorodiphenyltrichloroethane
(DDT), which is used as an insecticide, contains carbon, hydrogen, and
chlorine atoms. As mentioned earlier, these compounds are still considered
organic even though they contain heteroatoms and not just carbon and
hydrogen atoms. Today, a variety of useful organic compounds, like those
shown above, are made from simple starting compounds and they are not
obtained from natural sources. Various drugs, pesticides, herbicides, plastic
bottles, and various household cleaners are examples of compounds that are
synthesized from simple starting compounds. A specific branch of
chemistry that deals with the synthesis of such compounds from simple
starting compounds is called organic synthesis. Today’s pharmaceutical
industries routinely synthesize important drugs to cure various diseases, but
there are many factors that must be considered before a decision is made to
synthesize a particular drug or to isolate it from nature as was typically
done in the 1800s as pointed out earlier. It is extremely expensive to
develop a particular drug, and isolation from natural sources has
environmental impacts that must be considered.
1.2 Electronic Structure of Atoms
Before we actually examine how atoms are bonded together to form
different organic molecules, we need to review our understanding and
concept of atoms, and more specifically, at the electronic level. There are
four elements that we will encounter frequently throughout our study of
organic chemistry: hydrogen (H), carbon (C), nitrogen (N), and oxygen (O).
You should locate these elements on the periodic table before continuing.
Note carefully their location on the periodic table in relationship to each
other and the various numbers that are associated with each atom. First, we
will review the electronic structure of these atoms. It is extremely important
APPLICATIONS
CHAPTER 1
Bonding and Structure of Organic
Compounds
1.1 Introduction
The word “organic” was first used to describe compounds that were derived
from plants or animals, but this term was later used to describe compounds
that contain mostly carbon and hydrogen atoms. Today, the term organic is
loosely used to describe food that is produced without the use of pesticides,
hormones, antibiotics, or fertilizers.
In organic chemistry, we will carry out a detailed study of the composition,
properties, and reactions of compounds that contain primarily carbon and
hydrogen atoms, also known as organic compounds. Even though many
organic compounds contain only carbon and hydrogen atoms, a large
percentage contains other atoms, such as oxygen, nitrogen, sulfur, as well as
halogens; these atoms are referred to as heteroatoms. Atoms other than
carbon and hydrogen that are present in organic compounds are called
heteroatoms.
Prior to the start of the nineteenth century, chemists were familiar with
inorganic compounds; for example, it was known that ammonium cyanate,
an inorganic compound, could be easily made by the exchange reaction
shown in reaction (fig 1:1)
,Even though organic compounds were known, similar reactions that could
be used for their synthesis were not known. Instead, organic compounds
were obtained primarily from natural sources, such as extraction from
plants and other natural sources. As early as 1828, a medical doctor,
Friedrich Wöhler, synthesized urea, a known organic compound. The
synthesis of urea was accomplished by heating ammonium cyanate (an
inorganic compound), as shown by the reaction (fig1:2)
This was a major discovery that initiated the era of organic chemistry. For
the first time, an organic compound could be synthesized and these types of
compounds did not have to be obtained naturally. In the early 1800s, just
about all compounds that were used for different reasons, mostly medical,
were obtained from natural sources. Today, a large percentage of organic
compounds, including urea, which is a major component of fertilizer,
adhesives, and resins, are synthesized and are not obtained naturally.
, You may be wondering where are the carbon and hydrogen atoms in these
compounds since they are not shown in the structure, except for the first
structure, which shows two representations of N,N‐diethyl‐3‐
methylbenzamide (DEET). You will learn later in this chapter that at each
intersection in the structure, there are carbon and hydrogen atoms or just
carbon atoms. DEET contains carbon, hydrogen, oxygen, and nitrogen
atoms. Ibuprofen, a painkiller, contains carbon, hydrogen, and oxygen
atoms. The artificial sweetener, saccharin, contains carbon, hydrogen,
oxygen, nitrogen, and sulfur atoms. Dichlorodiphenyltrichloroethane
(DDT), which is used as an insecticide, contains carbon, hydrogen, and
chlorine atoms. As mentioned earlier, these compounds are still considered
organic even though they contain heteroatoms and not just carbon and
hydrogen atoms. Today, a variety of useful organic compounds, like those
shown above, are made from simple starting compounds and they are not
obtained from natural sources. Various drugs, pesticides, herbicides, plastic
bottles, and various household cleaners are examples of compounds that are
synthesized from simple starting compounds. A specific branch of
chemistry that deals with the synthesis of such compounds from simple
starting compounds is called organic synthesis. Today’s pharmaceutical
industries routinely synthesize important drugs to cure various diseases, but
there are many factors that must be considered before a decision is made to
synthesize a particular drug or to isolate it from nature as was typically
done in the 1800s as pointed out earlier. It is extremely expensive to
develop a particular drug, and isolation from natural sources has
environmental impacts that must be considered.
1.2 Electronic Structure of Atoms
Before we actually examine how atoms are bonded together to form
different organic molecules, we need to review our understanding and
concept of atoms, and more specifically, at the electronic level. There are
four elements that we will encounter frequently throughout our study of
organic chemistry: hydrogen (H), carbon (C), nitrogen (N), and oxygen (O).
You should locate these elements on the periodic table before continuing.
Note carefully their location on the periodic table in relationship to each
other and the various numbers that are associated with each atom. First, we
will review the electronic structure of these atoms. It is extremely important
