Bridging Titanium Nitrido Complexes Containing A Linear Ti-N-Ti Core with A Two-Coordinate Nitrido Ligand.

A series of titanium μ-nitrido complexes supported by the triamidoamine ligand Xy-NN (Xy-NN={(3,5-MeCH)NCHCH}N) is reported. The titanium azido complex [(Xy-NN)TiN] (1-N), prepared by salt metathesis of the chloride complex [(Xy-NN)TiCl] (1-Cl) with NaN, reacted with lithium metal or with alkali metal naphthalenides (alkali metal M=Na, K, and Rb) in THF to give the corresponding dinuclear μ-nitrido complexes M[(Xy-NN)Ti=N-Ti(Xy-NN)] (2-M; M=Li, Na, K, Rb). Single crystal X-ray diffraction studies of 2-Li, 2-Na, and 2-K revealed alkali metal dependent structures in the solid state.

Hydrogenolysis of Cationic Half-Sandwich Zinc Complexes Containing a Chelating Amine: Facile Cleavage of Zinc-Carbon Bond by Dihydrogen to Give Zinc Hydride Cations.

Cationic half-sandwich zinc complexes containing chelating amines [Cp*Zn(L)][BAr ] (2 a, Cp*=η-CMe, L=N,N,N',N'-tetramethylethylenediamine, TMEDA; 2 b, L=N,N,N',N'-tetraethylethylenediamine, TEEDA; 2 c, Cp*=η-CMe, L=N,N,N',N'',N''-pentamethyldiethylenetriamine, PMDTA; Ar =(3,5-(CF)CH)) reacted with dihydrogen (ca. 2 bar) in THF at 80 °C to give molecular zinc hydride cations [(L)ZnH(thf)][BAr ] (3 a,b, m=1; 3 c, m=0) previously reported along with Cp*H. Pseudo first-order kinetics with respect to the concentration of 2 b suggests heterolytic cleavage of dihydrogen by the Zn-Cp* bond, reminiscent of σ-bond metathesis.

Dihydrogen Cleavage by a Zinc-Zinc Bond of a Heteroleptic Dizinc(I) Cation.

Oxidative addition of dihydrogen across a metal-metal bond to form reactive metal hydrides in homogeneous catalysis is known for transition metals but not for zinc(I)-zinc(I) bond as found in Carmona's eponymous dizinconene [ZnCp*] (Cp* = η-CMe). Dihydrogen reacted with the heteroleptic zinc(I)-zinc(I) bonded cation [(L)Zn-ZnCp*][BAr] (L = TMEDA, ,,,-tetramethylethylenediamine, TEEDA, ,,,-tetraethylethylenediamine; Ar = 3,5-(CF)CH) under 2 bar at 80 °C to give the zinc(II) hydride cation [(L)ZnH(thf)][BAr] along with zinc metal and Cp*H derived from the intermediate [Cp*ZnH]. DFT calculations show that the cleavage of dihydrogen occurs through a highly unsymmetrical transition state.

Engineered Anchor Peptide LCI with a Cobalt Cofactor Enhances Oxidation Efficiency of Polystyrene Microparticles.

A typical component of polymer waste is polystyrene (PS) used in numerous applications, but degraded only slowly in the environment due to its hydrophobic properties. To increase the reactivity of polystyrene, polar groups need to be introduced. Here, biohybrid catalysts based on the engineered anchor peptide LCI_F16C are presented, which are capable of attaching to polystyrene microparticles and hydroxylating benzylic C-H bonds in polystyrene microparticles using commercially available oxone as oxidant.