Complexes of heteroscorpionate trispyrazolylborate anionic ligands. Part III. X-ray crystallographic and NMR studies on cobalt(II) complexes with tris(pyrazolyl)borate anionic ligands obtained from 3,5-di-methylpyrazole and 3(5)-methyl,5(3)-phenylpyrazole

Hydrogen Bonding and Anion Binding in Structures of Tris(pyrazolyl)boratenickel(II) and Phosphate Esters

“…The Ni–N(Tp*) distances are not significantly different (2.027–2.111 Å) and are similar to the Ni–N(pz*) distance (2.047 Å). These bond lengths are typical of five‐coordinate (Tp)Ni II derivatives that show distorted square pyramidal geometry 17–19. The Ni–O bond length is 1.949(2) Å as that previously found for a five‐coordinate nickel complex 20.…”

Synthesis, X‐ray Crystallographic and 1H NMR Spectroscopic Structural Studies on Cobalt(II) Complexes of Homoscorpionate, Heteroscorpionates and Chiral Tris(pyrazolyl)borates Obtained from 5(3)‐Isopropyl‐3(5)‐phenylpyrazole and 3,5‐Dimethylpyrazole

“…The 1 H NMR spectra of [HB(3‐Ph,5‐ i Prpz) 2 (3,5‐diMepz)]CoTp, ( 5 , trace B), [HB(3‐Ph,5‐ i Prpz)(3‐ i Pr,5‐Phpz) 2 ]CoTp ( 6 , trace C), and [HB(3‐ i Pr,5‐Phpz)(3‐Ph,5‐ i Prpz) 2 ]CoTp ( 7 , trace D) reveal that mutual rotation of the Tp and heteroscorpionate Tp x ligands around the central metal ion at 298 K is slow on the timescale of the method; the resonances of the 3‐H, 4‐H, and 5‐H protons of the Tp ligand appear as two signals with a ratio of intensities of 2:1. Other Tp x CoTp complexes bearing Tp x heteroscorpionates − [HB(3‐Ph,5‐Mepz) 2 (3‐Me,5‐Phpz)] − ,10 [HB(3‐Ph,5‐Mepz) 2 (3,5‐diMepz)] − ,14 and [HB(3‐Ph,5‐Mepz) 2 (3,5‐diEtpz)] − ,24 − behave similarly.…”

“…Previously, we demonstrated that heating of [hydro(3,5dimethylpyrazolyl)bis(5‐methyl‐3‐phenylpyrazolyl)borato](thiocyanato)cobalt( II ) {[HB(3‐Ph,5‐Mepz) 2 (3,5‐diMepz)]Co(NCS)} in propylbenzene at 428 K led to the formation of [hydro(3,5‐dimethylpyrazolyl)(3‐methyl‐5‐phenylpyrazolyl)(5‐methyl‐3‐phenylpyrazolyl)borato](thiocyanato)cobalt( II ) complex, containing a chiral Tp x ligand, in ca. 30% yield 14. The reaction was accompanied by formation of other products, namely [hydro(3,5‐dimethylpyrazolyl)bis(3‐methyl‐5‐phenylpyrazolyl)borato](thiocyanato)cobalt( II ) and complexes later identified as Tp x Co(NCS) species containing Tp x ligands of different composition resulting from cross‐exchange of pyrazole units between the two Tp x ligands 11.…”

Anionic Poly(pyrazolyl)borate Ligands Obtained from 3,5-Dimethylpyrazole and 3,5-Diphenylpyrazole and Their Cobalt(II) Complexes − X-ray Crystallographic and1H NMR Studies

“…of Ph,MepzH and 1 equiv. of 3,5‐diMepzH with sodium borohydride 4. This first‐step condensation led to the isolation of a mixture of Tp′ and Bp′ products, some of which were converted into high‐spin cobalt(II) complexes, characterized structurally by X‐ray crystallography in the solid state and 1 H NMR spectroscopy in solution.…”