Intermolecular Interaction and Magnetic Coupling Mechanism of a Mononuclear Nickel(II) Complex

Abstract

The mononuclear complex [Ni(HOphen)(OSO3)(H2O)3]·5H2O (HOphen = 1, 10‐phenanthrolin‐2‐ol) was prepared and its single structure was determined by X‐ray crystallography. In this complex, the NiII ion has a distorted octahedral arrangement. Crystal structure analysis shows that two kinds of π–π stacking interactions and C–H···O short contact intermolecular interactions exist among the adjacent complexes. Fitting to the variable‐temperature magnetic susceptibility data gave the magnetic coupling constant, 2J = –0.98 cm–1. Theoretical calculations, based on density functional theory (DFT) coupling with the broken‐symmetry approach (BS), revealed that the π–π stacking magnetic coupling pathways resulted in weak ferromagnetic interactions with 2J = 4.86 cm–1 and 2J = 4.16 cm–1, respectively, for the adjacent NiII ions with separations of 8.568(19) Å and 8.749(32) Å, respectively; whereas the magnetic coupling pathway of the C–H···O short contact intermolecular interaction led to a weak antiferromagnetic interaction with 2J = –17.62 cm–1 for the adjacent NiII ions with a separation of 10.291(26) Å. The ferromagnetic coupling sign can be explained by the McConnell I spin‐polarization mechanism.

Homoleptic Mononuclear Tris‐Chelate Complexes of FeII, CoII, NiII, and ZnII Based on a Redox‐Active Imidazolyl‐2‐thione Ligand: Structural and Electrochemical Correlation

“…Nonetheless, these values are in agreement with the HS‐state assignment performed by SC‐XRD for 1 and 2 (see above). The χT product for the three complexes is maintained relatively constant down to 50 K for 1 and 2 , whereas for 3 the decrease is observed below 11 K. Upon further cooling an abrupt decrease of the χT product is observed for the three complexes due to zero field splitting, and/or intermolecular antiferromagnetic coupling, in good agreement with the literature. At 2 K the χT product values are 0.67, 1.41 and 0.75 cm 3 K mol –1 for 1 – 3 , respectively.…”

Quantum chemical studies of non-covalent interactions between the ethyl cation and rare gases

“…Nowadays, the studies of interatomic interactions have attained a level of complexity never seen before [1][2][3][4][5]. Besides dihydrogen bonds [6][7][8][9][10], halogen bonds [11][12][13][14], dihydride-halogen bonds [15][16][17], beryllium bonds [18], and pnicogen bonds [19,20], in general the electron flux on these interactions occur from high-electron-density centers, such as proton acceptors, towards the electrondepleted ones, which are represented by hydrogen donors [21][22][23][24].…”

Divergent Solution and Solid-State Structures of Mono- and Dinuclear Nickel(II) Pyridone Complexes

“…For example, Winpenny and co-workers leveraged the propensity for nickel to form polynuclear oxo-bridged clusters in the presence of 2-pyridone ligands to synthesize so-called “metal cages” to study the relationship between the structure and magnetic properties of metal and metal oxide materials, , with application in data storage using single-molecule magnets. ,, While great focus has been given to Ni–pyridone complexes of high nuclearity, comparatively less attention has been paid to the synthetic control of mononuclear Ni–pyridone complexes. Seven monomeric Ni–pyridone complexes have been reported in the literature (excluding families of closely related compounds), and it is notable that all of these structures contain either polydentate supporting ligandssuch as scorpionate or triazacyclododecaneor a pyridone ligand that is, itself, polydentate. − These polydentate ligands block coordination sites at the nickel center, thus hindering pyridone ligands from achieving high nuclearity. It has also been observed that the formation of lower-nuclearity Ni–pyridone complexes is favored when the reaction and crystallization are performed in polar solvents such as methanol, ethanol, and acetonitrile …”