Generalized Turnstile Rotation: Formulation, Visualization, Workflow Implementation, and Application for Modeling...

Area of Science:

• Computational Chemistry
• Coordination Chemistry
• Molecular Dynamics

Background:

• Turnstile rotation is a key polytopal rearrangement mechanism in coordination compounds.
• Conventional internal coordinates struggle to represent large-amplitude, collective motions like turnstile rotation.
• Accurate computational modeling of these dynamic processes is crucial for understanding chemical reactivity and stability.

Purpose of the Study:

• To develop a generalized mathematical formulation for N-arm turnstile rotation.
• To create user-friendly computational tools (PyMOL plugin gTA and command-line utility gTA-cli) for visualizing and manipulating structures during turnstile rotation.
• To establish a practical computational workflow for studying fluxionality and dynamic stereochemistry in coordination complexes.

Main Methods:

• Developed a mathematical framework for generalized N-arm turnstile rotation.
• Created the gTA PyMOL plugin for visualization and gTA-cli for manipulation.
• Implemented a computational workflow combining turnstile rotation-driven relaxed scans with transition state location methods.

Main Results:

• Successfully applied the generalized turnstile rotation approach to five diverse chemical systems, including SF4, IF7, [Co(en)3]3+, and novel bismuth and nickel complexes.
• Identified transition states for pronounced polytopal rearrangements that are challenging to access with standard computational methods.
• Demonstrated the generality and effectiveness of the developed computational workflow in studying complex molecular motions.

Conclusions:

• Generalized turnstile rotation is a fundamental molecular motion with broad applicability in coordination chemistry.
• The developed gTA tools and computational workflow provide a powerful strategy for investigating fluxionality and dynamic stereochemistry.
• This work facilitates the computational study of complex rearrangements, previously inaccessible with conventional techniques.