(2R,2'S)-2,2'-Bi-piperidine-1,1'-diium dibromide

Area of Science:

• Organic Chemistry
• Crystallography
• Supramolecular Chemistry

Background:

• 2,2'-dipyridyl is a common ligand in coordination chemistry.
• Piperidine derivatives are important in pharmaceuticals and materials science.
• Understanding the stereochemistry and crystal packing of organic salts is crucial for material design.

Purpose of the Study:

• To synthesize and characterize the meso form of 2,2 -bi-piperidine.
• To elucidate the stereochemistry and conformational properties of the synthesized compound.
• To investigate the crystal structure and intermolecular interactions within the solid state.

Main Methods:

• Synthesis via reduction of 2,2 -dipyridyl using a Nickel-Aluminum alloy and Potassium hydroxide.
• Separation of diastereoisomers (meso and racemic) through recrystallization from ethanol.
• Characterization using X-ray crystallography to determine molecular structure and crystal packing.

Main Results:

• The title compound, C10H22N2 (2+).2Br(-), was successfully synthesized and identified as the achiral meso form of 2,2 -bi-piperidine.
• The meso form possesses an (S,R) configuration at the bridging carbon atoms, with both piperidinium rings adopting chair conformations and trans-oriented nitrogen atoms.
• X-ray crystallography revealed an inversion center at the midpoint of the central C-C bond and hydrogen bonding interactions forming sheets parallel to the (100) plane.

Conclusions:

• The synthesis and structural characterization confirm the formation of the achiral meso-2,2 -bi-piperidine.
• The observed conformation and hydrogen bonding network provide insights into the self-assembly behavior of organic diammonium salts.
• This study contributes to the understanding of stereoisomerism and crystal engineering in organic compounds.