Trans and cis influences in hypervalent iodine(III) complexes: a DFT study.

Area of Science:

• Computational Chemistry
• Organic Chemistry
• Hypervalent Iodine Chemistry

Background:

• Hypervalent iodine compounds exhibit unique reactivity due to their unusual bonding.
• Understanding ligand influences is crucial for predicting and controlling their chemical behavior.

Purpose of the Study:

• To investigate the trans and cis influences of various ligands in acyclic and heterocyclic hypervalent iodine compounds.
• To identify sensitive parameters for quantifying these influences and correlate them with compound stability.

Main Methods:

• Computational investigation of two isomeric structures: acyclic Ph[XI(OH)] and heterocyclic Ph[(heterocycle)I(OH)].
• Analysis based on I-OH bond distance (d), electron density at the bond critical point (ρ), I-OH stretching frequency (ν), and molecular electrostatic potential minimum (Vmin).

Main Results:

• Vmin was identified as the most sensitive parameter for quantifying trans and cis influences.
• Heterocyclic λ(3)-iodanes exhibited smaller trans influence than acyclic counterparts.
• Ligand inductive nature dictated the relative order of trans and cis influences, with electron-withdrawing ortho substitution strengthening the hypervalent I-OH bond.

Conclusions:

• The quantified trans/cis influences correlate directly with the stability of products from nucleophilic attack.
• This relationship aids in predicting nucleophile interaction energy in hypervalent iodine complexes.
• The findings are valuable for designing stable acyclic and heterocyclic hypervalent complexes.