0000000000412032
AUTHOR
Vibha Mishra
Coordination versatility of 1,3-bis[3-(2-pyridyl)pyrazol-1-yl]propane: Co(II) and Ni(II) complexes
Abstract The ligand 1,3-bis[3-(2-pyridyl)pyrazol-1-yl]propane (L8) has afforded six-coordinate monomeric and dimeric complexes [(L8)CoII(H2O)2][ClO4]2 (1), [(L8)NiII(MeCN)2][BPh4]2 (2), [(L8)NiII(O2CMe)][BPh4] (3), and [ ( L 8 ) 2 Co 2 II ( μ - O 2 CMe ) 2 ] [ BPh 4 ] 2 ( 4 ) . The crystal structures of 1, 2 · MeCN, 3, and 4 revealed that the ligand L8 is flexible enough to expand its coordinating ability by fine-tuning the angle between the chelating fragments and hence folds around cobalt(II)/nickel(II) centers to act as a tetradentate chelate, allowing additional coordination by two trans-H2O, cis-MeCN, and a bidentate acetate affording examples of distorted octahedral Co II N 2 ( pyridy…
Bis‐μ‐pyrazolate‐Bridged Dinickel(II) and Dicopper(II) Complexes: An Example of Stereoelectronic Preference of Metal Ions and Stabilization of Mixed‐Valence Ni III Ni II Species
New dimeric nickel(II) and copper(II) complexes [(L)Ni(μ-L′)]2[ClO4]21 and [(L)Cu(μ-L′)]2[ClO4]22, [2-[3-(2′-pyridyl)pyrazol-1-ylmethyl]pyridine (L) and 3-(2-pyridyl)pyrazole (HL′)] have been synthesized, structurally characterized, and their absorption, magnetic, EPR and redox properties investigated. The crystal structure of 1·MeCN reveals a planar {Ni2(μ-L′)2}2+ core [Ni···Ni separation: 4.0765(10) A] in which each distorted octahedral NiII ions is terminally coordinated by a tridentate ligand L and bridged by two HL′ units, in their deprotonated form. The structural analysis of 2·2MeCN reveals two five-coordinate CuII ions, each terminally coordinated by adopting only a bidentate coordi…