Structural and spectroscopic comparison of five-coordinate cobalt(II) and nickel(II) thiolato complexes with the related four-coordinate complexes

Distorted tetrahedral nickel-nitrosyl complexes: spectroscopic characterization and electronic structure

“…However, the 4-H proton of the pyrazolyl ring is observed to have the largest downfield shift to 81.09 ppm (integration of 3 protons) in [Ni(SC 6 F 5 )(L1)] [70]. This is a general tendency for complexes containing the Tp ligand [69,70,83]. The large shift comes from the deshielding effects of the aromatic pyrazolyl ring current and the paramagnetic contact shift [83,84].…”

“…This is a general tendency for complexes containing the Tp ligand [69,70,83]. The large shift comes from the deshielding effects of the aromatic pyrazolyl ring current and the paramagnetic contact shift [83,84].…”

Nickel tris(pyrazolyl)borate β-diketonate complexes

“…There is a single peak for the pyrazolyl protons indicative of fast rotation of the Tp Ph2 ligand. Such fluxional behaviour is well documented in first row transition metal Tp R complexes [11,12,[14][15][16]. It is also interesting to note the position of the pyrazolyl protons appears to correlate with the electronic properties of the substituent groups on the b-diketonate ligands.…”

“…1) [11,12,[14][15][16][17]. The related [Tp Ph2 Ni(OAc)] and [Tp Ph2 Ni(NO 3 )] compounds exhibit bands at 416, 708 and 420, 686 nm, respectively, implying that the b-diketonate ligands exert a stronger ligand field than either the acetate or nitrate ligand [11].…”

Synthesis, spectral characterization, density functional theory studies, and biological screening of some transition metal complexes of a novel hydrazide–hydrazone ligand of isonicotinic acid

“…[57][58][59] The electronic spectrum of complex 2 [Co (H 2 L)Cl(H 2 O)]H 2 O shows d-d bands at 680, 600, and 500 nm, which were consistent with five-coordinate cobalt complexes. [59][60][61] The electronic spectra with the square planar geometry of Ni(II) complexes. [62] In general, three bands corresponding to 1…”