Open Chain Polyarsenides of the Lanthanides

Area of Science:

• Organometallic Chemistry
• Lanthanide Chemistry
• Main Group Chemistry

Background:

• Cobalt polyarsenide complexes serve as precursors for novel inorganic compounds.
• Divalent samarium complexes are potent reducing agents in organometallic synthesis.

Purpose of the Study:

• To synthesize and characterize novel mixed d/f polyarsenides.
• To investigate the coordination chemistry of lanthanides with open chain-like polyarsenide ligands.
• To elucidate the mechanism of polyarsenide formation.

Main Methods:

• Reaction of [(Cp'''Co)2(μ,η2:2-As2)2] with decamethylsamarocenes and related samarium complexes.
• X-ray crystallography for structural determination.
• Density functional theory (DFT) calculations.

Main Results:

• Synthesis of mixed d/f polyarsenides [(Cp'''Co)2As4Sm(η5-C5Me4R)2] (R=Me, n-propyl).
• These compounds are the first structural examples of open chain-like polyarsenides coordinated to lanthanides.
• Intramolecular As-As coupling within the cobalt complex after reduction by samarium is proposed as the formation mechanism.

Conclusions:

• The study reports the first open chain-like polyarsenides ligated to lanthanides.
• The formation mechanism involves reduction and intramolecular coupling of the cobalt polyarsenide precursor.
• DFT calculations provide insights into the structural transformations of the polyarsenide ligand.