From a nanoparticular solid-state material to molecular organo-f-element-polyarsenides

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Materials Science

Background:

• Lanthanide chemistry offers unique electronic properties for novel material synthesis.
• Polyarsenide ligands are challenging to synthesize and stabilize in molecular complexes.
• Divalent lanthanide compounds provide a versatile platform for multi-electron reduction reactions.

Purpose of the Study:

• To report a convenient synthetic pathway to molecular organo-lanthanide-polyarsenides.
• To detail the synthesis of f-element complexes featuring the largest known polyarsenide ligands.
• To explore the reactivity of nanoscale gray arsenic with divalent lanthanide reducing agents.

Main Methods:

• Activation of solid-state nanoscale gray arsenic (As⁰_nano).
• Utilizing multi-electron reducing agents: divalent lanthanide complexes [K(18-crown-6)][(Ln^+II)₂(μ-η⁶:η⁶-C₆H₆)] and [K(18-crown-6)]₂[(Ln^+II)₂(μ-η⁶:η⁶-C₆H₆)].
• Directing product formation by varying the applied lanthanide reactant.

Main Results:

• Successful synthesis of organo-lanthanide-polyarsenides using nanoscale gray arsenic.
• Formation of Zintl anions As₃^3-, As₇^3-, and As₁₄^4-, previously inaccessible in molecular 4f-element chemistry.
• Characterization of compounds containing the As₁₄^4- moiety, representing the largest organo-lanthanide-polyarsenides to date.

Conclusions:

• A novel and convenient synthetic route to organo-lanthanide-polyarsenides has been established.
• Divalent lanthanide compounds serve as effective multi-electron reducing agents for arsenic activation.
• The study expands the scope of lanthanide chemistry and polyarsenide ligand synthesis.