Seeking Extremes in Molecular Design: To What Extent May Two "Non-Bonded" Hydrogen Atoms be Squeezed in a

Rohoullah Firouzi1, Shant Shahbazian2

  • 1Department of Physical Chemistry, Chemistry and Chemical Engineering Research Center of Iran, P.O. Box 14968-13151, Tehran, Iran. RFirouzi@ccerci.ac.ir.

Related Concept Videos

Hydrogen Bonds01:04

Hydrogen Bonds

A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
16.2K
Hydrogen Bonds00:26

Hydrogen Bonds

Hydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
136.3K
Structure of Alkanes02:23

Structure of Alkanes

The formation of carbon-carbon bonds leading to the creation of the carbon chain is the basis of organic chemistry. August Kekulé and Archibald Scott Couper independently developed this idea of carbon chain formation.
Hydrocarbons are the simplest organic compounds composed of carbons and hydrogens. Based on the bond order between carbons, the hydrocarbons are further classified into alkanes, alkenes, and alkynes. 
Alkanes are the simplest hydrocarbons with sp3 hybrid carbon atoms....
37.4K
Degree of Unsaturation02:05

Degree of Unsaturation

The degree of unsaturation (U), or index of hydrogen deficiency (IHD), is defined as the difference in the number of pairs of hydrogen atoms between the compound and the acyclic alkane with the same number of carbon atoms. Each double bond or ring costs two hydrogen atoms compared to a saturated analog and results in one degree of unsaturation.
The degree of unsaturation for hydrocarbons is U = (2C + 2 − H) / 2, where C is the number of carbon atoms and H is the number of hydrogen atoms.
11.4K
Organic Compounds03:02

Organic Compounds

All living things are formed mostly of carbon compounds called organic compounds. The category of organic compounds includes both natural and synthetic compounds that contain carbon. Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms. However, some carbon-containing compounds such as carbonates, cyanides, and...
58.7K
Molecular Shapes01:18

Molecular Shapes

Molecules have characteristic shapes that are crucial for their function. The arrangement of various electron groups around the central atom dictates their molecular geometry. Electron pairs in the valence shell of a central atom will adopt an arrangement that minimizes repulsions between the electron pairs by maximizing the distance between them. The valence electrons form either bonding pairs, located primarily between bonded atoms, or lone pairs.
Two regions of electron density in a diatomic...
63.3K