Crystal structure and Hirshfeld surface analysis of 2-picolyllithium·3thf

Area of Science:

• Inorganic Chemistry
• Crystallography
• Supramolecular Chemistry

Background:

• Organolithium compounds are crucial in organic synthesis.
• Understanding the coordination chemistry of lithium ions with organic ligands is essential for catalyst design.
• The 2-picolyl anion and tetrahydrofuran (THF) are common motifs in organometallic chemistry.

Purpose of the Study:

• To elucidate the crystal structure and coordination environment of a novel lithium-2-picolyl complex.
• To investigate the bonding interactions and packing motifs in the solid state.
• To analyze the role of tetrahydrofuran ligands in stabilizing the lithium complex.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
• The coordination geometry around the lithium ion was analyzed.
• Hirshfeld surface analysis was used to quantify intermolecular interactions and packing contributions.

Main Results:

• The lithium ion adopts a distorted tetrahedral coordination geometry, bonded to the nitrogen of the 2-picolyl anion and three oxygen atoms of THF ligands.
• The 2-picolyl anion exists in its enamido form, with the lithium ion situated close to the pyridine ring plane.
• A methylene group in one THF ligand exhibits positional disorder.
• Hirshfeld surface analysis indicates that H⋯H contacts (86%) are the dominant feature in the crystal packing, followed by C⋯H/H⋯C (10.4%) and O⋯H/H⋯O (3%) interactions.

Conclusions:

• The study provides detailed structural insights into a lithium-2-picolyl complex coordinated by THF.
• The observed coordination geometry and crystal packing are influenced by a combination of Li-N, Li-O bonds, and weaker intermolecular forces.
• The findings contribute to the understanding of bonding and structural diversity in organolithium compounds.