HSAB principle and nickel(II) ion reactivity towards 1-methyhydantoin

Acidity and basicity interplay in amide and imide self-association

“…There is a considerable body of theoretical and experimental work which is concordant with the JSIH. For example, crystallographic data of some imides such as maleimide, trans -3,4-diphenylsuccinimide, and 1-methyl-hydantoin show that the separation between O S and O HB is very long (>4 Å) 12 in agreement with the proposed repulsive character of the interaction of these atoms. Additionally, the JSIH has also been successfully used to study tetrapeptide analogues, 13 stabilisation of base-pairs (A–T and G–C), 14 and triply hydrogen bonded complexes.…”

Ni(II) complex with sarcosine derived from in situ generated ligand: structural, spectroscopic, and DFT studies

“…A much higher value for the solid state (b = 0.94) was found than for solution (b = 0.76). This means that ionicity of M-L bond in solid state is significantly higher than in solution, which was observed earlier for other Ni(II) complexes [11]. information about the strength of a ligand in the crystal field, i.e., its ability to split metal d levels in the electrostatic environment [46].…”

“…1 T 2g = 21,400 cm -1 ). This indicates higher, i.e., pseudooctahedral, symmetry of (1) in solution [11].…”

“…On the basis of the band positions, crystal field and Racah B parameters for solid state and solution were calculated ( [10,11,47,48]. Crystal field Dq parameter in D 4h symmetry has a slightly different meaning than that in O h symmetry, because CF splitting in the former is described by three parameters: Dq, Ds, and Dt [49].…”

“…1). Hydantoin and its derivatives at moderate temperature and pH form complexes with metal ions [10][11][12][13]. However, when elevated temperature and extreme pH are applied, hydantoins hydrolyze, forming in the most cases, amino acids [14].…”