Hydration Structure of ₁₀₂No²⁺: A Density Functional Theory-Molecular Dynamics Study.

Area of Science:

• Computational Chemistry
• Physical Chemistry
• Radiochemistry

Background:

• Understanding the hydration structure of divalent cations is crucial for predicting their behavior in aqueous solutions.
• Nobelium (No2+), a superheavy element, exhibits unique chemical properties that require detailed investigation.
• Previous studies suggest similarities between No2+ and lighter alkaline earth metal ions like Ca2+ and Sr2+.

Purpose of the Study:

• To investigate the hydration structure of the divalent nobelium ion (No2+) in water.
• To validate computational methods for simulating systems containing superheavy elements.
• To compare the hydration behavior of No2+ with Ca2+ and Sr2+.

Main Methods:

• Ab initio molecular dynamics (MD) simulations were employed.
• Density functional theory (DFT) calculations were used to validate the chosen MD methods.
• Benchmark calculations were performed on Ca2+ and Sr2+ systems prior to simulating No2+.

Main Results:

• The hydration distance of No2+ was found to be intermediate between Ca2+ and Sr2+.
• The simulated hydration distance trend aligns with experimental elution position data.
• The average No-O bond length in [No(H2O)8]2+ was calculated to be 2.55 Å.

Conclusions:

• The hydration structure of No2+ exhibits characteristics between Ca2+ and Sr2+.
• Dynamic solvent effects, including the second coordination sphere, are important for accurate theoretical calculations of superheavy element solution chemistry.
• Computational MD simulations provide valuable insights into the aqueous chemistry of rare and superheavy elements.