ESR studies of rhodium atoms deposited from thermal sources into hydrocarbon matrices at 77 K

Abstract

Thermally generated rhodium atoms have been trapped in an adamantane matrix at 77 K and the resulting X- and K-band ESR spectra investigated over a range of temperatures. All three g-shifts of the observed orthorhombic spectrum are well resolved and the spectrum is assigned to neutral Rh atoms trapped in asymmetric matrix sites. The spectra were well simulated with the following parameters: g₁ = 2.761, g₂ = 2.572, g₃ = 1.940 and A₁ = 305 MHz, A₂ = 284 MHz, A₃ = 244 MHz. These are used to estimate spin density contributions of 0.55 (4d), 0.22 (5s) and 0.23 (5p) toward the ground state electronic configuration of the trapped atoms.