Configuration of Octahedral Metal Compounds − Equilibrium, Crystal and Molecular Structure of Nickel(II) Complexes of Linear N₂O₄, N₄S₂ or N₆ Donors Set Atoms Ligands

Abstract

2+ complex, however, the size of the thioether sulfur atoms imposes a C 2v symmetry; the pyridyl groups and the sulfur atoms are in trans positions and all

l-Tyrosinatonickel(II) Complex: Synthesis and Structural, Spectroscopic, Magnetic, and Biological Properties of 2{[Ni(l-Tyr)2(bpy)]}·3H2O·CH3OH

“…The Ni–O2, −O4, −N1, −N2, −N3, and −N4 distances in the [Ni( l -Tyr) 2 (bpy)] unit ( 1 ; Table ) are all different; thus, the symmetry around the six-coordinated Ni 2+ center is only C 1 . The noticeable asymmetry of the d–d bands indicates that those bands are probably split under crystal-field symmetry lower than O h . − This spectrum was thus filtered for the purpose of obtaining the refined band splitting and energies of its components. The filtering process revealed that the first d–d band is composed of three maxima at 9460, 10650, and 11210 cm –1 (Figure and Table ).…”

“…In D 2 h ( C 2 ″) symmetry, the 3 B 1g term is the ground state and nine spin-allowed transitions, 3 B 1g → 3 A g , 3 B 1g → 3 B 2g , and 3 B 1g → 3 B 3g (I st d–d), 3 B 1g → 3 B 1g , 3 B 1g → 3 B 2g , and 3 B 1g → 3 B 3g (II d–d), 3 B 1g → 3 B 1g , 3 B 1g → 3 B 2g , and 3 B 1g → 3 B 3g (III d–d), are possible as a result of splitting of 3 T 2g ( 3 F, O h ), 3 T 1g ( 3 F, O h ), and 3 T 1g ( 3 P, O h ) states in a rhombic crystal field (Table ). − The three components of the I d–d band are centered at 9460, 10650, and 11210 cm –1 , respectively. The II d–d band includes three separate components obtained at 16060, 17100, and 18600 cm –1 .…”

Synthesis and Characterization of Copper Complexes Containing the Tripodal N7 Ligand Tris{2‐[(pyridin‐2‐ylmethyl)amino]ethyl}amine (=N′‐(Pyridin‐2‐ylmethyl)‐N,N‐bis{2‐[(pyridin‐2‐ylmethyl)amino]ethyl}ethane‐1,2‐diamine): Equilibrium, Spectroscopic Data, and Crystal Structures of Mono‐ and Trinuclear Copper(II) Complexes

“…We previously reported the coordination of Ni- [4], and Cu-and Zn-atoms [5] with linear hexadendate ligands involving two pyridinylmethyl groups and containing donor N-and O-atoms or N-and S-atoms. These studies show that the thermodynamic stability, the structural configuration, and the redox properties of these mononuclear complexes depend on the nature of the two central donor heteroatoms.…”