TY - JOUR
T1 - Three-Coordinate Halide and Methyl Complexes of Chromium, Manganese, Iron, Cobalt, and Nickel Enabled by an Imidazolin-2-iminato Ligand
AU - Chen, Guan Wen
AU - Chen, Yu Hsuan
AU - Liu, Hsin Kuan
AU - Lin, Chun Yi
N1 - Funding Information:
We thank the National Science and Technology Council (NSTC, previously Ministry of Science and Technology, MOST) of Taiwan (Young Scholar Fellowship Program, MOST 108-2636-M-006-011, 109-2636-M-006-018, 110-2636-M-006-009, 111-2636-M-006-020, and 108-2113-M-006-015-MY2) and the National Cheng Kung University (through Higher Education Sprout Project of the Ministry of Education of Taiwan) for support of this work. We are grateful to the Core Facility Center at the National Cheng Kung University for the use of the Bruker D8 Venture Single Crystal X-ray Diffractometer (XRD003100), Bruker AV-500 NMR spectrometer (NMR005000), Quantum Design MPMS SQUID VSM (SQUID000200), and Elementar UNICUBE (EA000600). We also thank Professor Ho-Hsuan Chou and Dr. Tsu Lien Hung for the use of Shimadzu UV-1800 spectrophotometer in his lab and crystallographic assistance, respectively. We thank the reviewers for their invaluable comments and suggestions.
Publisher Copyright:
© 2023 American Chemical Society
PY - 2023/9/11
Y1 - 2023/9/11
N2 - Accessing low-coordinate halide and methyl complexes requires a bulky monodentate or bidentate ligand. Here, the synthesis and characterization of three-coordinate terminal halide and methyl complexes of the first-row transition metals are reported. The halide complexes could be accessed by the reaction of 1 molar equivalent (equiv) of M(II) halides (M = Cr, Mn, Fe, Co, and Ni) and one equiv of the bulky imidazolin-2-iminato ligand NImDipp- (1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato). Three-coordinate bridging (for Cr) and terminal (for Mn, Fe, and Co) methyl complexes could be synthesized by the reaction of [M(μ2-NImDipp)(X)]2 and LiCH3 or CH3MgCl in a 1:2 molar ratio. Single-crystal X-ray diffractometry (SC-XRD) revealed that Mn, Fe, and Co complexes have dimeric structures with terminal methyl ligands in the form of [M(μ2-NImDipp)(CH3)]2. In contrast, the Cr analog is a tetranuclear Cr4 cluster [Cr4(μ2-NImDipp)2(μ2-CH3)6] with both bridging NImDipp and CH3 ligands. Superconducting quantum interference device (SQUID) magnetometry studies of these methyl complexes showed that the metal ions are antiferromagnetically coupled. Furthermore, the catalytic activities of the methyl complexes and the nickel halide complex were also tested in Kumada cross-coupling reactions, and [Ni(μ2-NImDipp)(Cl)]2 was found to be the best catalyst among the complexes.
AB - Accessing low-coordinate halide and methyl complexes requires a bulky monodentate or bidentate ligand. Here, the synthesis and characterization of three-coordinate terminal halide and methyl complexes of the first-row transition metals are reported. The halide complexes could be accessed by the reaction of 1 molar equivalent (equiv) of M(II) halides (M = Cr, Mn, Fe, Co, and Ni) and one equiv of the bulky imidazolin-2-iminato ligand NImDipp- (1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato). Three-coordinate bridging (for Cr) and terminal (for Mn, Fe, and Co) methyl complexes could be synthesized by the reaction of [M(μ2-NImDipp)(X)]2 and LiCH3 or CH3MgCl in a 1:2 molar ratio. Single-crystal X-ray diffractometry (SC-XRD) revealed that Mn, Fe, and Co complexes have dimeric structures with terminal methyl ligands in the form of [M(μ2-NImDipp)(CH3)]2. In contrast, the Cr analog is a tetranuclear Cr4 cluster [Cr4(μ2-NImDipp)2(μ2-CH3)6] with both bridging NImDipp and CH3 ligands. Superconducting quantum interference device (SQUID) magnetometry studies of these methyl complexes showed that the metal ions are antiferromagnetically coupled. Furthermore, the catalytic activities of the methyl complexes and the nickel halide complex were also tested in Kumada cross-coupling reactions, and [Ni(μ2-NImDipp)(Cl)]2 was found to be the best catalyst among the complexes.
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U2 - 10.1021/acs.organomet.3c00316
DO - 10.1021/acs.organomet.3c00316
M3 - Article
AN - SCOPUS:85171542649
SN - 0276-7333
VL - 42
SP - 2395
EP - 2404
JO - Organometallics
JF - Organometallics
IS - 17
ER -