What does the term cation pi interactions refer to?
Cation–π interaction is a noncovalent molecular interaction between the face of an electron-rich π system (e.g. benzene, ethylene, acetylene) and an adjacent cation (e.g. Li+, Na+). This interaction is an example of noncovalent bonding between a monopole (cation) and a quadrupole (π system).
How are anion pi interactions possible?
There is evidence, however, that even non-electron deficient aromatic rings can establish anion-π interactions if the ring is simultaneously interacting with a cation on the opposite face of the ring.
Are ion pi interactions strong?
The cation-π interaction was considered to contribute 2.6 kcal/mol to the binding interaction. Based on these and other studies, Diederich concluded that “the cation-π interaction is one of the strongest driving forces in biological complexation processes”.
What are electrostatic interactions?
Electrostatic interactions comprise the attractive or repulsive interactions between charged molecules. In most cases, electrostatic interactions are generally combined with other interactions for material repair.
What is pi stacking strength?
In chemistry, pi stacking (also called π–π stacking) refers to the presumptive attractive, noncovalent interactions (orbital overlap) between the pi bonds of aromatic rings.
What is pi alkyl bond?
These pi-alkyl, pi-pi T shaped and pi-Sulphur interactions comes in the broad category of non-covalent interactions. In pi-alkyl interactions there is interaction of pi- electron cloud over an aromatic group and electron group of any alkyl group.
What does electrostatic interaction mean?
Are cation pi interactions stronger than hydrogen bonds?
(1) Ten of the twenty natural amino acids are involved in the three types of strong interactions (salt-bridge, cation-π and amide bridge), which are much stronger than typical hydrogen bonds and often play important roles in protein-protein, protein-peptide, protein-ligand, and protein-DNA interactions.
What is another name of electrostatic interactions?
Electrostatic interaction (van der Waals interaction): The attractive or repulsive interaction between objects having electric charges.
What is the difference between van der Waals and electrostatic interactions?
Van der Waals force is the sum of the attractive and the repulsive non-bond forces between atoms or molecules other than the electrostatic forces. Although the van der Waals force between two carbon atoms is very weak, there are a lot of van der Waals forces between two particles, leading to a very strong interaction.
What is aromatic stacking?
Aromatic stacking interactions arise from the attractive force between the π-electron clouds in the neighboring aromatic groups. The aromatic stacking is common between proteins and small molecules. The stacking interactions at the interfaces of proteins and other macromolecules are relatively rare.
Is pi stacking a hydrophobic interaction?
Although π-π stacking, defined as an attractive, non-covalent interaction between aromatic rings, is not as widespread as hydrogen bonds and hydrophobic contacts, it plays a vital role in biological recognition and the organization of biomolecular structures.
What do you mean by non-covalent interaction?
A non-covalent interaction differs from a covalent bond in that it does not involve the sharing of electrons, but rather involves more dispersed variations of electromagnetic interactions between molecules or within a molecule.
Is pi stacking van der Waals?
π–π interaction is a particular type of dispersion force from van der Waals forces, which is established between unsaturated (poly)cyclic molecules (114). Carbon nanotubes and graphene have the same hexatomic ring of carbon atoms and therefore can be spontaneously stacked with each other by the π–π interactions (115).
Are electrostatic interactions the same as ionic bonds?
The key difference between ionic and electrostatic interactions is that ionic interactions describe the attraction force between two opposite ionic species. Meanwhile, electrostatic interactions describe the attraction force between two completely or partially ionized species with opposite charges.
Is pi stacking hydrogen bonding?
π–π stacking and hydrogen bonding interactions are found to play essential roles in this intermolecular electron transfer process. π–π stacking provides large fragment orbital overlaps between the unoccupied orbitals of the analyte and sensor, which serves as a highly efficient electron transfer bridge.
What is Vander Waals force interaction?
A van der Waals interaction is a relatively weak force ranging from 0.5 to 1 kcal/mol and is nonionic in nature. Neutral molecules containing electronegative atoms, like oxygen and nitrogen, have a tendency to draw the electron cloud toward itself through the covalent bond from its less electronegative neighbor atom.
What is stacking interaction in DNA?
Base stacking. Base stacking is a common arrangement of nucleobases found in the three dimensional structure of nucleic acids. Bases (or base pairs) are planar, and these planes stack at contact distance (about 3.4 Angstrom), excluding water and maximizing Van der Waals interactions.
What are the four types of noncovalent interactions?
Non-covalent interactions can be classified into different categories, such as electrostatic, π-effects, van der Waals forces, and hydrophobic effects.
Do cation-cation and anion-anion attractive interactions exist?
Do cation-cation and anion-anion attractive interactions exist? The pairing of ions of opposite charge is one of the dogmas in chemistry and ion-pairs or ionic interactions often govern chemical reactions or more particularly such processes as synthesis or catalysis. Usually, there is no doubt that ions possess opposite charges.
Are anions excluded from the ion atmosphere?
Previous experiments have focused primarily on the cations that are attracted to nucleic acid polyanions, but have also showed that anions are excluded from the ion atmosphere.
Does cation-cation pairing exist in 4-oxopiperidinum salts?
This is why the recent report on the existence of cation-cation pairing by hydrogen bond interactions in crystal structures of 4-oxopiperidinum salts seems to be surprising 1.
Do stabilizing interactions strengthen separated cations?
The recent experimental study seems to prove conclusively that separated cations not supported by interactions with anions are linked by stabilizing interactions. To describe the recent study let us start from the history of this topic.