Hydroboration Reactivity of Niobium Bis(N-heterocyclic carbene)borate Complexes.

Title Hydroboration Reactivity of Niobium Bis(N-heterocyclic carbene)borate Complexes.
Authors J.A. Ziegler; C. Prange; T.D. Lohrey; R.G. Bergman; J. Arnold
Journal Inorg Chem
DOI 10.1021/acs.inorgchem.8b00247
Abstract

The syntheses of high-valent niobium imido complexes [HB(Im)]Nb(N Bu)Cl (2) and [HB(Im)]Nb(N Bu)Me (3) bearing a bis(NHC)borate (NHC = N-heterocyclic carbene) supporting ligand are described. The reaction of the dimethyl complex (3) with excess CO generates an equivalent of acetone, which inserts into a B-H bond of the bis(NHC)borate ligand to form a boryl isopropoxide/niobium(III) dicarbonyl complex (4). This mode of hydroboration reactivity also occurs readily upon the treatment of either 2 or 3 with ketones, aldehydes, and isocyanates. Modification of the bis(carbene) ligand of 3 via the hydroboration of benzophenone produces the dimethylniobium complex [(OCHPh)B(Im)]Nb(N Bu)Me (12), which undergoes intramolecular ?-arene coordination upon hydrogenation.

Citation J.A. Ziegler; C. Prange; T.D. Lohrey; R.G. Bergman; J. Arnold.Hydroboration Reactivity of Niobium Bis(N-heterocyclic carbene)borate Complexes.. Inorg Chem. 2018. doi:10.1021/acs.inorgchem.8b00247

Related Elements

Niobium

See more Niobium products. Niobium (atomic symbol: Nb, atomic number: 41) is a Block D, Group 5, Period 5 element with an atomic weight of 92.90638. Niobium Bohr ModelThe number of electrons in each of niobium's shells is 2, 8, 18, 12, 1 and its electron configuration is [Kr] 4d4 5s1. The niobium atom has a radius of 146 pm and a Van der Waals radius of 207 pm. Niobium was discovered by Charles Hatchett in 1801 and first isolated by Christian Wilhelm Blomstrand in 1864. In its elemental form, niobium has a gray metallic appearance. Niobium has the largest magnetic penetration depth of any element and is one of three elemental type-II superconductors (Elemental Niobiumalong with vanadium and technetium). Niobium is found in the minerals pyrochlore, its main commercial source, and columbite. The word Niobium originates from Niobe, daughter of mythical Greek king Tantalus.

Boron

See more Boron products. Boron Bohr ModelBoron (atomic symbol: B, atomic number: 5) is a Block P, Group 13, Period 2 element with an atomic weight of 10.81. The number of electrons in each of boron's shells is 2, 3 and its electron configuration is [He] 2s2 2p1. The boron atom has a radius of 90 pm and a Van der Waals radius of 192 pm. Boron was discovered by Joseph Louis Gay-Lussac and Louis Jacques Thénard in 1808 and was first isolated by Humphry Davy later that year. Boron is classified as a metalloid is not found naturally on earth. Elemental BoronAlong with carbon and nitrogen, boron is one of the few elements in the periodic table known to form stable compounds featuring triple bonds. Boron has an energy band gap of 1.50 to 1.56 eV, which is higher than that of either silicon or germanium. The name Boron originates from a combination of carbon and the Arabic word buraqu meaning borax.

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