Noncovalent Interactions

Noncovalent Interactions

Interactions that do not involve the sharing of electron pairs, such as ionic bonds and dipole-dipole interactions.

Ionic Bond

A bond formed through electrostatic interactions between ions of opposite charges, such as NaCl.

Covalent Bond

A bond in which two atoms share one or more pairs of electrons.

Polar Covalent Bond

A type of bond where the electrons are shared unequally between two atoms with different electronegativities.

Electronegativity

The measure of an atom's ability to attract and hold electrons.

Dipole Moment

A measure of the polarity of a bond or molecule, represented by the separation of positive and negative charges.

Debyes

Units used to measure dipole moments, where 1 D = 3.336 x 10^-30 C·m.

Formal Charge

An accounting of the charges on atoms in a molecule, calculated using the electron bookkeeping method.

Dielectric Constant

A measure of a solvent’s ability to reduce the electrostatic forces between charged particles.

Hydrogen Bond

An attractive interaction between a hydrogen atom bonded to a more electronegative atom and another electronegative atom.

Dipole-Dipole Interaction

Interactions between molecules that have dipole moments, where positive and negative ends attract.

London Dispersion Forces

Weak intermolecular forces resulting from temporary changes in electron density.

Van der Waals Radius

The optimal radius of interaction between two atoms, based on their size and the distance at which they can closely approach each other.

Hydrophobic Pocket

An area within a protein that excludes water, enhancing the interaction between nonpolar molecules.

Symmetric Molecule

A molecule whose dipole moments cancel out due to equal distribution of charges.

Asymmetric Molecule

A molecule lacking symmetry, resulting in a net dipole moment.

Interaction Energy

The energy associated with the interaction between charged species or molecules.

Energy of Interaction

The strength of interaction between charged particles or polar molecules affected by distance.

Inductive Effect

The shifting of electron density in a bond due to electronegativity differences.

Nonpolar Molecules

Molecules that do not have permanent dipole moments due to symmetrical distribution of charge.

Electrostatic Interaction

The attraction or repulsion between charged particles.

Monovalent Ion

An ion with a single positive or negative charge.

Polyatomic Ion

An ion composed of two or more atoms that are covalently bonded and have an overall charge.

Sustainable Energetics

The energy calculations concerning noncovalent interactions, especially in macromolecules.

Force Field Model

A computational method to calculate the energy of interactions of molecular systems.

Ionic Interaction

Interactions between charged species that can substantially affect molecular structures.

Hydrogen Donor

An atom (usually hydrogen) that provides a hydrogen bond to another atom.

Hydrogen Acceptor

An atom that receives a hydrogen bond from a hydrogen donor.

Electrostatic Forces

Forces arising from charged particles that can attract or repel one another.

Strength of Hydrogen Bonds

Typically between 10 to 30 kJ/mol, indicative of their significance in biochemistry.

C—C Covalent Bond

A bond between two carbon atoms where electrons are shared equally.

Polarity

The distribution of electrical charge over the atoms in a molecule.

Lewis Structure

A diagram that shows the bonding between atoms and the lone pairs of electrons in a molecule.

Partial Charge

The charge distribution that occurs due to differences in electronegativity between atoms.

Electrons in Covalent Bonds

Electrons that are shared between two atoms in a covalent bond, influencing molecular shape and polarity.

Oxygen in Molecular Bonds

Oxygen is often a hydrogen bond acceptor due to its high electronegativity and availability of lone pairs.

Chlorine Electronegativities

Chlorine's electronegativity is about 3.0, influencing its behavior in polar covalent bonds.

Microscopic Interactions

The interactions at the atomic and molecular levels that dictate macroscopic properties in materials.

Biomolecular Interactions

The various types of interactions that occur between biological molecules.

Symmetry in Molecules

Geometric configuration that can affect dipole moments and molecular polarity.