TY - JOUR
T1 - Copper(I), Silver(I), and Gold(I) Ethylene Complexes of Fluorinated and Boron-Methylated Bis- and Tris(pyridyl)borate Chelators
AU - Watson, Brandon T.
AU - Vanga, Mukundam
AU - Noonikara-Poyil, Anurag
AU - Muñoz-Castro, Alvaro
AU - Dias, H. V.Rasika
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under grant number (CHE-1954456, HVRD). A.M.-C. acknowledge FONDECYT 1221676 grant.
Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/1/30
Y1 - 2023/1/30
N2 - Bis- and tris-pyridyl borate ligands containing pyridyl donor arms, a methylated boron cap, and a fluorine-lined coordination pocket have been prepared and utilized in coinage metal chemistry. The tris(pyridyl)borate ligand has been synthesized using a convenient boron source, [NBu4][MeBF3]. These N-based ligands permitted the isolation of group 11 metal-ethylene complexes [MeB(6-(CF3)Py)3]M(C2H4) and [Me2B(6-(CF3)Py)2]M(C2H4) (M = Cu, Ag, Au). The gold complexes display the largest coordination-induced upfield shifts of the ethylene 13C resonance relative to that of the free ethylene in their NMR spectra, while the silver complexes show the smallest shift. Solid-state structures of five of these metal-ethylene complexes as well as the related free ligands were established by X-ray crystallography. Surprisingly, all three [MeB(6-(CF3)Py)3]M(C2H4) adopt the rare κ2 coordination mode rather than the typical κ3 coordination mode of facial capping tridentate ligands. Computational analyses indicate that κ2 coordination mode is favored over the κ3-mode in these coinage metal-ethylene complexes and point to the effects CF3-substituents have on κ2/κ3-energy difference. The M-C and M-N bond distances of [MeB(6-(CF3)Py)3]M(C2H4) follow the trend expected based on covalent radii of M(I) ions. The calculated ethylene-M interaction energy of κ2-[MeB(6-(CF3)Py)3]M(C2H4) indicated that the gold(I) forms the strongest interaction with ethylene. A comparison to the related poly(pyrazolyl)borates is also presented.
AB - Bis- and tris-pyridyl borate ligands containing pyridyl donor arms, a methylated boron cap, and a fluorine-lined coordination pocket have been prepared and utilized in coinage metal chemistry. The tris(pyridyl)borate ligand has been synthesized using a convenient boron source, [NBu4][MeBF3]. These N-based ligands permitted the isolation of group 11 metal-ethylene complexes [MeB(6-(CF3)Py)3]M(C2H4) and [Me2B(6-(CF3)Py)2]M(C2H4) (M = Cu, Ag, Au). The gold complexes display the largest coordination-induced upfield shifts of the ethylene 13C resonance relative to that of the free ethylene in their NMR spectra, while the silver complexes show the smallest shift. Solid-state structures of five of these metal-ethylene complexes as well as the related free ligands were established by X-ray crystallography. Surprisingly, all three [MeB(6-(CF3)Py)3]M(C2H4) adopt the rare κ2 coordination mode rather than the typical κ3 coordination mode of facial capping tridentate ligands. Computational analyses indicate that κ2 coordination mode is favored over the κ3-mode in these coinage metal-ethylene complexes and point to the effects CF3-substituents have on κ2/κ3-energy difference. The M-C and M-N bond distances of [MeB(6-(CF3)Py)3]M(C2H4) follow the trend expected based on covalent radii of M(I) ions. The calculated ethylene-M interaction energy of κ2-[MeB(6-(CF3)Py)3]M(C2H4) indicated that the gold(I) forms the strongest interaction with ethylene. A comparison to the related poly(pyrazolyl)borates is also presented.
UR - http://www.scopus.com/inward/record.url?scp=85146605677&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.2c04009
DO - 10.1021/acs.inorgchem.2c04009
M3 - Article
C2 - 36657123
AN - SCOPUS:85146605677
SN - 0020-1669
VL - 62
SP - 1636
EP - 1648
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 4
ER -