The electron spin resonance spectrum of Al[C2H4] in hydrocarbon matrices

Abstract

Al[C₂H₄] is formed from Al atoms and C₂H₄ on solid hydrocarbons at 77 K in a rotating cryostat. It has the magnetic parameters a‖(Al)= 123 MHz, a‖(Al)=–14 MHz, a_Al= 31 MHz, a_H(4)= 7.5 MHz, g‖= 2.0026, g⊥= 2.0047 and g= 2.004. This complex is remarkably stable and persists in adamantane up to 297 K. The structure and bonding of Al[C₂H₄] is still in some doubt, but the magnetic parameters and stability suggest a strong σ as well as π interaction between the Al atom and the ethylene group.