A Mononuclear and High-Spin Tetrahedral TiIIComplex

Reinholdt A, Pividori DM, Laughlin AL, Dimucci IM, MacMillan SN, Jafari MG, Gau MR, Carroll PJ, Krzystek J, Ozarowski A, Telser J, Lancaster KM, Meyer K, Mindiola DJ (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Inorganic Chemistry American Chemical Society

DOI: 10.1021/acs.inorgchem.0c02586

Abstract

A high-spin, mononuclear TiII complex, [(TptBu,Me)TiCl] [TptBu,Me- = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate], confined to a tetrahedral ligand-field environment, has been prepared by reduction of the precursor [(TptBu,Me)TiCl2] with KC8. Complex [(TptBu,Me)TiCl] has a 3A2 ground state (assuming C3v symmetry based on structural studies), established via a combination of high-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy, solution and solid-state magnetic studies, Ti K-edge X-ray absorption spectroscopy (XAS), and both density functional theory and ab initio (complete-active-space self-consistent-field, CASSCF) calculations. The formally and physically defined TiII complex readily binds tetrahydrofuran (THF) to form the paramagnetic adduct [(TptBu,Me)TiCl(THF)], which is impervious to N2 binding. However, in the absence of THF, the TiII complex captures N2 to produce the diamagnetic complex [(TptBu,Me)TiCl]2(η1,η1μ2-N2), with a linear TiNNTi topology, established by single-crystal X-ray diffraction. The N2 complex was characterized using XAS as well as IR and Raman spectroscopies, thus establishing this complex to possess two TiIII centers covalently bridged by an N22- unit. A πacid such as CNAd (Ad = 1-adamantyl) coordinates to [(TptBu,Me)TiCl] without inducing spin pairing of the d electrons, thereby forming a unique high-spin and five-coordinate TiII complex, namely, [(TptBu,Me)TiCl(CNAd)]. The reducing power of the coordinatively unsaturated TiII-containing [(ptBu,Me)TiCl] species, quantified by electrochemistry, provides access to a family of mononuclear TiIV complexes of the type [(TptBu,Me)TiE(Cl)] (with E2- = NSiMe3, N2CPh2, O, and NH) by virtue of atom- or group-transfer reactions using various small molecules such as N3SiMe3, N2CPh2, N2O, and the bicyclic amine 2,3:5,6-dibenzo-7-azabicyclo[2.2.1]hepta-2,5-diene.

Authors with CRIS profile

Daniel Maximilian Pividori Lehrstuhl für Anorganische und Allgemeine Chemie Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie

Involved external institutions

University of Pennsylvania US United States (USA) (US) Cornell University US United States (USA) (US) Florida State University (FSU) US United States (USA) (US) Roosevelt University US United States (USA) (US)

How to cite

APA:

Reinholdt, A., Pividori, D.M., Laughlin, A.L., Dimucci, I.M., MacMillan, S.N., Jafari, M.G.,... Mindiola, D.J. (2020). A Mononuclear and High-Spin Tetrahedral TiIIComplex. Inorganic Chemistry. https://dx.doi.org/10.1021/acs.inorgchem.0c02586

MLA:

Reinholdt, Anders, et al. "A Mononuclear and High-Spin Tetrahedral TiIIComplex." Inorganic Chemistry (2020).

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