Probing intramolecular interactions in arylselenides using a property descriptor based approach

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Organic Chemistry

Background:

• Intramolecular nonbonding interactions involving chalcogen atoms are well-documented in organometallic compounds.
• Previous research primarily focused on contact distances, neglecting quantitative measures of interaction strength.
• Selenium-chalcogen (Se...X, where X = O, S, N) interactions represent an important class of nonbonding interactions.

Purpose of the Study:

• To quantify the strength of intramolecular Se...X nonbonding interactions in organoselenium compounds.
• To introduce and validate a new scheme using molecular property descriptors for interaction quantification.
• To evaluate the efficacy of nucleus-independent chemical shift (NICS) values as a descriptor for these interactions.

Main Methods:

• Employed nucleus-independent chemical shift [NICS(0)] values as a molecular property descriptor.
• Utilized ab initio MP2 and density functional theory (DFT) methods.
• Used Dunning's cc-pVDZ basis set for all calculations.
• Compared NICS(0) results with thermochemical methods (homodesmic and ortho-para).

Main Results:

• NICS(0) values successfully quantified the strength of exocyclic Se...X nonbonding interactions in aryl selenides.
• Calculated interaction strengths showed sensitivity to changes in the aryl ring center.
• The NICS(0) scheme provided a reliable alternative to existing thermochemical methods.

Conclusions:

• NICS(0) is a sensitive and effective descriptor for quantifying intramolecular Se...X nonbonding interactions.
• The proposed method offers a valuable tool for studying nonbonding interactions in organoselenium chemistry.
• This approach advances the understanding of nonbonding interactions beyond simple contact distance analysis.