Further investigations of linear trirhodium complexes: experimental and theoretical studies of [Rh3(dpa)4Cl2] and [Rh3(dpa)4Cl2](BF4) [dpa = bis(2-pyridyl)amido anion].
The linear trirhodium compound, Rh3(dpa)4Cl2 (1), and its one-electron oxidation product, [Rh3(dpa)4Cl2]BF4 (2), have been synthesized and studied extensively. The magnetic measurement for compound 1 shows that it possesses one unpaired electron that is assigned to occupy the sigma(nb) orbital (2A2) by DFT calculations. Upon oxidation, a beta-spin electron of 1 is removed, that causes compound 2 to exhibit a triplet ground state. DFT calculations indicate that the two unpaired electrons of 2 occupy sigma(nb) and delta* orbitals (3B1), which is supported by 1H NMR spectrum. Unlike their isoelectronic analogues [Co3(dpa)4Cl2] (3) and [Co3(dpa)4(Cl)2]BF4 (4), both compound 1 and 2 do not display the spin-crossover phenomenon. The reason may be attributed to the relative large energy gap between 3B1 and open-shell singlet 1B1 states.
Huang
Gin-Chen
GC
Department of Chemistry, National Taiwan University, Taipei, Taiwan, (ROC).
Liu
Isiah Po-Chun
IP
Kuo
Jau-Huei
JH
Huang
Yi-Lin
YL
Yeh
Chen-Yu
CY
Lee
Gene-Hsiang
GH
Peng
Shie-Ming
SM