Abstract
Nickel(II) complexes containing P-N-type bidentate hybrid ligands of 2-aminoethylphosphanes (RR'Pea; RR' = Ph2 or MePh) or 8-quinolylphosphanes (RR'Pqn), namely [Ni(P-N)2](BF4) 2 [P-N = Ph2Pea (1), MePhPea (2), Ph2Pqn (3), or MePhPqn (4)] have been prepared, and their structural, spectroscopic, and electrochemical properties determined. The crystal structure analysis indicates that: the 2-amlnoethylphosphane complexes (1 and 2) have a square-planar coordination geometry around the NiII center with a cis(P,P) configuration, whereas the 8-quinolylphosphane complexes (3 and 4) exhibit a severe tetrahedral distortion because of the steric repulsion between the ortho-H atoms in the mutually cis-positioned quinolyl rings, Complexes 1 and 2 maintain their diamagnetic square-planar four-coordinate structure on acetonitrile solution, whereas complexes 3 and 4 show paramagnetic behavior. Spectroscopic and electrochemical measurements suggest that the ligand-field strengths of these four PN-type ligands increase in the order Ph2Pqn (3) < MePhPqn (4) < Ph2Pea (1) < MePhPea (2). The Ph 2Pqn complex 3 is readily reduced by Zn powder to afford the corresponding nickel(I) complex [Ni(Ph2Pqn)2]BF 4 (5), The crystal structure of complex 5 reveals that the Ni I ion adopts a distorted tetrahedral coordination geometry with slightly longer (≈ 0.05 Å) Ni-P and. Ni-N bond lengths than those in the corresponding NiII complex 3.
Original language | English |
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Pages (from-to) | 39-47 |
Number of pages | 9 |
Journal | European Journal of Inorganic Chemistry |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 19 2010 |
Keywords
- Ligand effects
- N,p ligands
- Nickel
- Phosphane ligands
ASJC Scopus subject areas
- Inorganic Chemistry