Synthesis and characterization of coordinatively unsaturated nickel(ii) and manganese(ii) alkyl complexes supported by the hydrotris(3-phenyl-5-methylpyrazolyl)borate (TpPh,Me) ligand

Abstract

The synthesis of several nickel(II) and manganese(II) alkyl complexes supported by hydrotris(3-phenyl-5-methylpyrazolyl)borate (Tp(Ph,Me)) ligand is reported. The metal halide complexes Tp(Ph,Me)MnCl(CH3CN) (1) and Tp(Ph,Me)NiCl (4) were used as precursors for synthesis of Tp(Ph,Me)MnCH2Si(Me)3 (2), Tp(Ph,Me)MnCH2Ph (3), Tp(Ph,Me)NiCH2Si(Me)3 (5) and Tp(Ph,Me)NiCH2Ph (6). The resulting Mn(II) and Ni(II) alkyl complexes, 2-3 and 5-6, were characterized by X-ray crystallography, NMR spectroscopy, and FT-IR spectroscopy. X-ray crystallographic analysis revealed distorted tetrahedral geometries for complexes 2-3 and 5 with a κ(3)-Tp(Ph,Me). Complex 6, on the other hand, was found to have a distorted square planar geometry with κ(2)-Tp(Ph,Me) and an η(3)-benzyl ligand. Transformations of 4 and Tp(Ph,Me)CoCl (10) via treatment with NaN3 to yield Tp(Ph,Me)NiN3 (11), Tp(Ph,Me)CoN3 (12), along with the synthesis of (Tp(Ph,Me))2Ni (8) and Tp(Ph,Me)NiCl(3-Ph-5MepzH) (9) are also reported.

Scorpionato Halide Complexes [(TpPh,Me)Ni–X] [X = Cl, Br, I; TpPh,Me = Hydrotris(3‐phenyl‐5‐methyl‐1‐pyrazolyl)borate]: Structures, Spectroscopy, and Pyrazole Adducts

“…Synthesis and characterization of [(Tp Ph,Me )Ni-Cl] were reported previously; [7,18] in the present work, a disolvated pseudo-polymorph [(Tp Ph,Me )Ni-Cl]· 2CH 2 Cl 2 was obtained, as well as the halide complexes [(Tp Ph,Me )Ni-X] (X = Br, I). [20][21][22][23] [19] We also investigated the pentacoordinate pyrazole adducts [(Tp Ph,Me )Ni(Hpz Ph,Me )(X)] (X = Cl, I); the pentaco-ordinate pyrazole adduct [(Tp Ph,Me )Ni(Hpz Ph,Me )(Cl)] was reported previously, [20][21][22][23] but the iodide analogue reported herein is new.…”

“…The structural and spectroscopic data have been rationalized by DFT calculations. [19] We also investigated the pentacoordinate pyrazole adducts [(Tp Ph,Me )Ni(Hpz Ph,Me )(X)] (X = Cl, I); the pentaco-ordinate pyrazole adduct [(Tp Ph,Me )Ni(Hpz Ph,Me )(Cl)] was reported previously, [20][21][22][23] but the iodide analogue reported herein is new. The analogous series [(Tp Me,Me )Ni-X] (X = Cl, Br, I) was reported previously.…”

Activation of heteroallenes by coordinatively unsaturated nickel(ii) alkyl complexes supported by the hydrotris(3-phenyl-5-methyl)pyrazolyl borate (TpPh,Me) ligand

“…[19][20][21] Such reactivity has been observed for RNCS and OCS, which are known to undergo carbon-sulfur bond cleavage by transition metal complexes. 43 Here we present the insertion of CS 2 into the square planar Tp Ph,Me NiCH 2 Ph, which resulted in the formation of a square planar insertion product Tp Ph,Me Ni(η 2 -CS 2 )CH 2 Ph with an η 2 -C,S bonding motif. 34,35 Based on our interest in utilizing reactive metal-carbon bonds for activation of small molecules, [36][37][38][39][40][41][42] we investigated reactions of sulfur containing heteroallenes toward coordinatively unsaturated hydrotris( pyrazolyl)borate nickel(II) alkyl complexes.…”

“…Tp Ph,Me NiCH 2 Ph (1a) and Tp Ph,Me NiCH 2 Si(CH 3 ) 3 (1b) 43 were prepared using literature procedures, and unless otherwise noted, all reagents were acquired from commercial sources. All glassware, cannulae, and Celite were stored in an oven at >425 K. All chemicals were used as received after being dried over 4 Å sieves for 48 hours and degassed with nitrogen.…”

Synthesis, and characterization of low- and high-spin manganese(II) complexes of polyfunctional adipoyldihydrazone: Effect of coordination of N-donor ligands on stereo-redox chemistry

“…The lower oxidation state species of manganese(II) are commonly 6-coordinate. Coordination number four with a distorted square-planar or tetrahedral geometry is known for the high-spin Mn(II) [12,13] but uncommon for low-spin manganese(II). We report herein, a lowspin Mn(II) complex with square-planar geometry and provide examples of high-spin Mn(II) complexes with octahedral geometry.…”