Chalcogen bond

N sigma star orbital interaction

Chalcogen gate topology

AIM analysis

Enantioselective acyl transfer

Chalcogen bonding refers to a type of noncovalent interaction involving a chalcogen atom (elements of group 16 in the periodic table, namely oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po)) in a molecular entity. This interaction is similar to hydrogen bonding and halogen bonding but involves chalcogens as the electron acceptors. Chalcogen bonds play a crucial role in various fields, including molecular recognition, supramolecular chemistry, and drug design, due to their ability to influence molecular assembly and structure.

Overview

Chalcogen bonding occurs when a chalcogen atom acts as an electrophile, or electron acceptor, interacting with a nucleophile, or electron donor, such as nitrogen, oxygen, or another chalcogen. This interaction is directional and can significantly influence the orientation and packing of molecules in crystals, impacting material properties and molecular recognition processes. The strength and directionality of chalcogen bonds make them valuable tools in the design of new materials and pharmaceuticals.

Types of Chalcogen Bonds

Chalcogen bonds can be classified based on the chalcogen involved in the interaction. The most commonly studied types are:

• Sulfur Bonds: Involving sulfur atoms, these are among the most common and well-understood chalcogen bonds.
• Selenium Bonds: Selenium, being more polarizable than sulfur, can form stronger chalcogen bonds.
• Tellurium Bonds: Tellurium bonds are even stronger due to the high polarizability of tellurium atoms.

Applications

Chalcogen bonding has found applications in several areas of chemistry and material science:

• In supramolecular chemistry, chalcogen bonds are used to construct complex molecular architectures with specific properties.
• In drug design, they can influence the binding affinity and specificity of drug molecules to their targets.
• In crystal engineering, chalcogen bonds can dictate the packing and orientation of molecules, affecting the material's physical properties.

Chalcogen Bonding vs. Other Noncovalent Interactions

Chalcogen bonding shares similarities with other noncovalent interactions like hydrogen and halogen bonds but has unique characteristics due to the nature of chalcogen atoms. Compared to hydrogen bonds, chalcogen bonds typically involve heavier atoms and can offer different directionalities and strengths. Compared to halogen bonds, they are generally weaker but can be more versatile due to the variety of chalcogen atoms.

Research and Development

Research in chalcogen bonding is ongoing, with scientists exploring its potential in novel material synthesis, environmental sensing, and the development of new pharmaceuticals. The ability to predict and manipulate these interactions is key to advancing their application in various fields.

Conclusion

Chalcogen bonding represents a fascinating area of study in chemistry, with significant implications for molecular design and material science. As research continues to uncover the nuances of these interactions, their potential applications are likely to expand, offering new possibilities in the design of functional materials and effective drugs.

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