Zwitterionic and biradicaloid heteroatomic cyclopentane derivatives containing different group 15 elements

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Synthetic Chemistry

Background:

• Exploration of novel bonding motifs in main group elements.
• Understanding the electronic structure and reactivity of low-valent main group compounds.

Purpose of the Study:

• To synthesize and characterize novel cyclopentane-1,3-diyl derivatives.
• To investigate the influence of different main group elements (N, P, As, Sb) on the electronic structure and reactivity of these derivatives.
• To differentiate between biradicaloid and zwitterionic character in these compounds.

Main Methods:

• Synthesis of [E1(μ-NTer)2({E2C} = NDmp)] derivatives via 1,1-insertion reactions.
• Characterization using computational methods (e.g., density functional theory).
• Reactivity studies, including housane formation and activation of unsaturated molecules.

Main Results:

• Successful synthesis of cyclopentane-1,3-diyl derivatives with varying main group elements (E1, E2).
• Insertion reactions were successful for N/P/As combinations but not for As/As or As/Sb.
• Compounds with P and As radical centers exhibited biradicaloid character, showing reactivity in housane formation and activation of multiple bonds (e.g., PCy3).
• Compounds with N,As- and N,P-centered biradicaloids were identified as zwitterionic species with diminished reactivity.

Conclusions:

• The nature of the main group elements (E1, E2) dictates the electronic structure (biradicaloid vs. zwitterionic) of cyclopentane-1,3-diyl derivatives.
• Biradicaloid character in P,As-centered compounds enables unique reactivity, including molecular activation.
• Zwitterionic character in N,As- and N,P-centered compounds leads to reduced reactivity.