|
|||||
|
|
Synthesis and spectroscopic investigations of four-coordinate nickel complexes supported by a strongly donating scorpionate ligand |
|
| Authors: | Ismael Nieto Andrew Ozarowski J. Krzystek Jeremy M. Smith |
| Affiliation: | a Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C, P.O. Box 30001, Las Cruces, NM 88003-8001, USA b Cabot Corporation, 5401 Venice Ave. N.E., Albuquerque, NM 87113, USA c National High Magnetic Field Laboratory, Florida State University, 1800 E. Paul Dirac Dr., Tallahassee, FL 32310, USA d Department of Biological, Chemical and Physical Sciences, Roosevelt University, 430 S. Michigan Ave., Chicago, IL 60605-1394, USA |
| Abstract: | Two four-coordinate nickel complexes, HB(tBuIm)3NiBr and HB(tBuIm)3NiNO, were prepared by reaction of a bulky tris(carbene)borate ligand with NiBr2(PPh3)2 and NiBr(NO)(PPh3)2, respectively, and structurally and spectroscopically characterized. In addition to standard techniques, high-frequency and -field electron paramagnetic resonance (HFEPR) was employed to understand the spin triplet (S = 1) ground state of the bromo complex. HFEPR, combined with electronic absorption spectroscopy allows comparison of this novel complex with other paramagnetic four-coordinate Ni(II) species. The tris(carbene)borate ligand is a stronger σ-donor than corresponding tris(pyrazolyl)borates (traditional “scorpionate” ligands). The tris(carbene)borate ligand may also act as a π-acceptor, in contrast to tris(pyrazolyl)borates, which show relatively little π-bonding interactions. The influence of tris(carbene)borate substituents on the donor strength of the ligand have been elucidated from IR spectroscopic investigations of {NiNO}10 derivatives. HFEPR spectra of HB(tBuIm)3NiBr exhibit hyperfine coupling from Br, which indicates the strong electronic interaction between Ni(II) and this halide ligand, consistent with studies on tris(pyrazolyl)borate Ni(II) complexes. |
| Keywords: | Scorpionate ligands Nickel complexes Spectroscopy |
| 本文献已被 ScienceDirect 等数据库收录！ | |