9-(Pyrrolidinium-1-yl)-9-boranuidabi-cyclo-[3.3.1]nona-ne.

Area of Science:

• Organometallic Chemistry
• Crystallography
• Structural Chemistry

Background:

• Organoboranes, such as 9-borabicyclo-[3.3.1]nonane (9-BBN), are versatile reagents in organic synthesis.
• Pyrrolidine is a common cyclic secondary amine used in various chemical applications.
• Adduct formation between Lewis acids (like boranes) and Lewis bases (like amines) is a fundamental chemical interaction.

Purpose of the Study:

• To elucidate the crystal structure of the adduct formed between 9-borabicyclo-[3.3.1]nonane (9-BBN) and pyrrolidine.
• To analyze the B-N bond characteristics and molecular geometry of the adduct.
• To investigate conformational variations within the crystallographically independent molecules.

Main Methods:

• Single-crystal X-ray diffraction analysis was employed to determine the crystal structure.
• The crystal system, space group, and unit cell parameters were identified.
• Bond lengths, bond angles, and conformational analyses were performed on the molecular structures.

Main Results:

• The compound C12H24BN crystallizes in the triclinic space group P with three molecules in the asymmetric unit.
• B-N bond lengths were determined to be in the range of 1.631(2) to 1.641(2) Å.
• All three molecules show chair conformations for the 9-BBN unit's six-membered rings, while the pyrrolidine rings exhibit diverse twisted and envelope conformations, with one molecule displaying disorder.

Conclusions:

• The crystal structure provides detailed insights into the bonding and conformation of the 9-BBN-pyrrolidine adduct.
• The observed conformational flexibility of the pyrrolidine ring is a key feature of this adduct.
• This structural characterization contributes to the understanding of organoborane-amine interactions and their solid-state properties.