Molecular titanium nitrides: nucleophiles unleashed

Abstract

Reactivity studies of a rare example of a molecular titanium nitride are presented. A combination of theory and NMR spectroscopy provide a description of the bonding in the these nitrides, the role of the counter cation, K+, as well as the origin of their highly downfield 15N NMR spectroscopic shifts.

Exceptional uranium(VI)-nitride triple bond covalency from 15N nuclear magnetic resonance spectroscopy and quantum chemical analysis

“…Accordingly, we list pertinent nitrides with both associated δ iso values (MeNO 2 /NH 3(l) = 0 ppm): 1* (δ iso = av. 971/1351 ppm); [V(N)(L MeDipp )(ODipp)] (δ iso = 679/1059 ppm, 48,49 ; [ T i ( μ-N)(NP) 2 K(18C6)] (δ iso = 542/922 ppm) 48,49 ; [Ti(μ-N)(NP) 2 K(OEt 2 )] 2 (δ iso = 512/ 892 ppm) 48,49 ;…”

“…The Ω value for 1* is notably large, and can be compared to those of [Ti(N)(NP) 2 ][K(2,2,2-crypt)] (Ω = 1470 ppm) 48,49 , [Mo(N){N(Bu t )(C 6 H 3 -3,5-Me 2 } 3 ] (Ω = 1187 ppm) 50 , [Ti(μ-N) (L ButDipp )(NTol 2 )K] 2 (Ω = 1155 ppm) 51 , and [(N″) 3 Th(μ-N) Th(N″) 3 ][K(18C6)(THF) 2 ] (Ω = 847 ppm) 26 . Thus, though there are comparatively few data for comparison, 1* exhibits the largest Ω of any nitrogen-containing molecule, enlarging the known tensor span range by ~500 ppm.…”

“…This is indeed the case, spanning a range of ≤2.8 eV and we note that the HOMO-LUMO gap of 1* is consistently close to the mean and median computed HOMO-LUMO gap over BP86, PBE0, and B3LYP functionals (Supplementary Table 5). Indeed, separately plotting 15 N δ iso values for the three unique, correlated U-N bonds in 1* (experimental nitride δ iso and extrapolated computed amide and amine δ iso values ) and available experimental data for 16 literature complexes 25,26,[46][47][48][49][50][51]65 -various M-NR 2 , M = NR, and M ≡ N (terminal and capped) bonds involving Th, Ti, Zr, V, and Mo-against Mayer, Nalewajski-Mrozek (NM), Delocalisation Index (DI), and interatomic exchangecorrelation energy (V XC ) 66 bond order metrics produces satisfactory linear correlated relationships with R 2 values ranging from 0.7240 (δ iso vs V XC ) to 0.8621 (δ iso vs Mayer) (Fig. 6 and Supplementary Figs.…”

Heterolytic Splitting of Molecular Hydrogen by Frustrated and Classical Lewis Pairs: A Unified Reactivity Concept

“…Namely, in the case of systems with bulky substituents, dispersion stabilizes the transition states by about 11–18 kcal mol −1 with respect to free reactants. In this context it is worth noting the crucial importance of dispersion in correctly describing and quantitatively understanding contemporary chemical problems, such as C–H bond activations 87 and Suzuki-Miyaura cross-coupling reactions 82 amongst many others 88 . Using the Non-Covalent Interaction method 72 , 73 we scrutinized the various secondary interactions that lead to this contribution of dispersion and, accordingly, demonstrated the presence of π–π stacking, C–F … H and other specific weak-interactions in the transition states and ion-pair products (see Figures S2 and S3 ).…”

Microfabrication atomic layer deposited Pt NPs/TiN thin film on silicon as a nanostructure signal Transducer: Electrochemical characterization toward neurotransmitter sensing

“…Furthermore, there is a synergistic effect between titanium oxynitride functional groups as active sites and titanium nitride functional groups as nucleophile center that cause intense interaction between DA and TiN/Air surface (Fig. 7b) [64,65]. Considering the substantial sensitivity of TiN/Air electrode toward DA sensing, development of Nafion/ MWCNTs/Pt NPs/TiN sensor was conducted based on TiN/Air sample.…”