Difference Between Saturated and Unsaturated Bonds

Thekey differencebetween saturated and unsaturated bonds is thata saturated bond has nopi bondswhereas unsaturated bonds always have pi bonds.

Chemical bonds are the linkages between atoms. These bonds cause the formation of molecules. There are two major types of bonds; they are thecovalent bonds and ionic bonds. However, the bonds in metals aremetallic bonds. Covalent bonds form when two atoms share their valence electrons. These covalent bonds can be either saturated or unsaturated depending on the number and type of bond existing between two atoms.

CONTENTS

1.Overview and Key Difference
2.What are Saturated Bonds
3.What are Unsaturated Bonds
4.并排比较 - 表格形式的饱和与不饱和键
5.概括

What are Saturated Bonds?

Saturated bonds are single bonds. These are covalent chemical bonds. There, two atoms bind with each other via a sigma bond, and thus, there are no pi bonds — the bond forms involving two electrons; one electron from each of the two atoms which form this bond. These electrons are the valence electrons of the atoms. The bond strength of this type of bond is comparatively weak. The two shared electrons exist in between the atoms, and the more electronegative atom will attract the electrons towards itself.

此外，这种类型的键具有进行旋转的能力。在那里，这种键充当旋转轴。遵循轨道相互重叠时，饱和键形成。

• Two s orbitals
• Two p_z轨道als
• S and p_z轨道al
• Two d_z²轨道als
• Linear overlapping of hybrid orbitals.

What are Unsaturated Bonds?

Unsaturated bonds are double bonds and triple bonds between two atoms. These are covalent bonds. Therefore, electrons are shared between atoms. Moreover, there are sigma bonds and pi bonds as well. In a double bond, there is a sigma bond and a pi bond between two atoms. In a triple bond, there is a sigma bond and two pi bonds. A sigma bond forms due to linear overlapping of atomic orbitals while the pi bonds form due to parallel overlapping.

同样，双键在原子之间具有四个键电子，而三键在那里有六个电子。由于不饱和结合中原子之间的大量电子，这些键往往更具反应性。此外，与单键相比，这些键更强和更短。

What is the Difference Between Saturated and Unsaturated Bonds?

饱和键是单键，不饱和键是两个原子之间的双键和三键。饱和键和不饱和键之间的关键区别在于，饱和键没有PI键，而不饱和键始终具有PI键。饱和键和不饱和键之间的另一个差异是，饱和键中两个原子之间有一个电子对，而不饱和键的原子之间有两个或三个电子对。

Furthermore, an important difference between saturated and unsaturated bonds is that the saturated bonds are comparatively weak, long, and less reactive whereas, the unsaturated bonds are strong, short, and more reactive. Moreover, saturated bonds can undergo rotations while unsaturated bonds cannot.

The below infographic is a comparison summary on difference between saturated and unsaturated bonds.

概括– Saturated vs Unsaturated Bonds

In summary, saturated bonds are single covalent bonds while unsaturated bonds are double and triple bonds. Therefore, the key difference between saturated and unsaturated bonds is that a saturated bond has no pi bonds whereas unsaturated bonds always have pi bonds.

Reference:

1. Helmenstine, Anne Marie, Ph.D. “Double Bond Definition and Examples in Chemistry.” ThoughtCo, Sep. 8, 2017.Available here
2. Britannica, The Editors of Encyclopaedia. “Triple Bond.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 14 Apr. 2011.Available here

Image Courtesy:

1.”Methane-2D-square” (Public Domain) viaCommons Wikimedia
2.弗雷德·尤斯特里（Fred oysteri）的“双键”(CC BY-SA 4.0)viaCommons Wikimedia