Wydział Chemii

Ewa Pacholska

Piotr J. Chmielewski

Lechosław Latos-Grażyński

1998

Inorganica Chimica Acta

273

184-190

10.1016/S0020-1693(97)06006-4

Naukowa

Angielski

Artykuł

Addition of aryl Grignard reagents to a toluene solution of nickel(II) monohalide complexes of 5.20-bis(p-tolyl)-10.15-diphenyl-21-oxaporphyrin (ODTDPPH) and 5.20-diphenyl-10.15-bis(p-tolyl)-21-selenaporphyrin (SeDPDTPH) at 203 K resulted in formation of paramagnetic σ-aryl nickel(II) derivatives which were identified and characterized by means of ¹H NMR. The coordination of the aryl ligand has been unambiguously proven by the unique downfield pattern of the corresponding resonances. The (σ-aryl)nickel(II) derivatives are in the high-spin electronic state: (d_xv)²(d_vz)²(d_vz)²(d_z²)²(d_z²)¹(d_{x² y²})¹. A homolytic cleavage of the Ni¹¹-C bond has been determined for (ODTDPP)Ni^II(Ar) and (SeDPDTP)Ni^II(Ar) in toluene with formation of low-valent nickel species: (ODTDPP)Ni and (SeDPDTP)Ni. One-electron reduction of (SeDPDTP)Ni^IICl to generate (SeDPDTP)Ni has been investigated by means of EPR, involving ⁶¹Ni isotope enrichment and spectral simulations. A considerable increase in metal d-orbital contribution to the singly occupied molecular orbital has been observed upon coordination of 1-methylimidazole to (SeDPDTP)Ni.

Nickel complexes, Paramagnetic complexes, Selenaporphyrin complexes

https://doi.org/10.1016/S0020-1693(97)06006-4

http://www.elsevier.com