A high-spin, mononuclear Ti-II complex, [(Tp(tBu,Me))TiCl] [Tp(tBu,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 [(T-tBu,T-Me)TiCl2] with KC8. Complex [(Tp(tBu,Me))TiCl] has a (3)A(2) ground state (assuming C-3, 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 Ti-II complex readily binds tetrahydrofuran (THF) to form the paramagnetic adduct {(Tp(tBu,Me))TiCl(THF)], which is impervious to N-2 binding. However, in the absence of THF, the Ti-II complex captures N-2 to produce the diamagnetic complex [(Tp(tBu,Me))TiCl](2)(eta(1),eta(1);mu(2)-N-2), with a linear Ti=N=N=Ti topology, established by single-crystal X-ray diffraction. The N-2 complex was characterized using XAS as well as IR and Raman spectroscopies, thus establishing this complex to possess two Ti-III centers covalently bridged by an N-2(2-) unit. A pi acid such as CNAd (Ad = 1-adamantyl) coordinates to [(Tp(tBu,Me))TiCl] without inducing spin pairing of the d electrons, thereby forming a unique high-spin and five-coordinate Ti-II complex, namely, [(Tp(tBu,Me))TiCI(CNAd)]. The reducing power of the coordinatively unsaturated Ti-II-containing [(Tp(tBu,Me))TiCl] species, quantified by electrochemistry, provides access to a family of mononuclear Ti-IV complexes of the type [(Tp(tBu,Me))Ti=-E(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.