Ni(salen): a System That Forms Many Solvates with Interacting Ni Atoms

Abstract

Recrystallization of [N,N’-Ethylene-bis(salicylideneiminato)]-nickel(II) [Ni(salen)] has been carried out from a large selection of solvents. Crystals can be either solvent free or solvates. This study is based on X-ray crystal structure determinations, which include the redetermination of Ni(salen) at low-temperature, the finding of three new solvates of Ni(salen), that is, Ni(salen)·CH2Cl2, Ni(salen)·AcOH, and Ni(salen)·1.5MeOH, and the reexamination of the known solvate Ni(salen)·chloroform at low- and room-temperature. The crystal structures of Ni(salen) and its solvates are stabilized by salen···salen and/or solvent···salen and/or solvent···solvent intermolecular interactions. A special case is the crystal structure of Ni(salen)·1.5MeOH where the salen/solvent ratio is 2:3 rather than 1:1. For all solvated structures, the solvent and Ni(salen) molecules always interact via Dsolvent−H···Osalen (Dsolvent = C, O) hydrogen bond interactions, the strengths of which depend on the solvent of recrystallization. All structures are characterized by weak Ni−Ni interactions, which are found either in centrosymmetric dimeric units or along one-dimensional chains. Such interactions are favored because of the d8 electronic configuration of Ni(II) and the pseudoplanar geometry of Ni(salen).

Zn2+‐Ion Sensing by Fluorescent Schiff Base Calix[4]arene Macrocycles

“…The fluorescenceo fH 2 Lw as also quenchedb yC o 2 + and Cu 2 + (see graphical abstract). [17,18] The UV/Vis spectrum of H 2 Li nC H 3 OH/CH 2 Cl 2 ( Figure 3) displayed two absorption bands at 346 and 447 nm, which are attributedt ot he p-p*a nd n-p*t ransitions, respectively,o ft he o,o'-bis(iminomethyl)phenol chromophoreo nt he basis of TDDFT calculations (Figures S25-S29) and literature reports. The X-ray structurer evealed the presence of am onomeric host-guest complex( Figure 2), with two MeCN molecules complexed by the calixareneu nits, as in other inclusion complexes.…”

Accurate prediction of vertical electronic transitions of Ni(II) coordination compounds via time dependent density functional theory

“…A particular type of superoxide dismutase (SOD) enzyme also contains nickel(II) . The distortion of the geometry (so‐called pseudoplanar) has been observed in the case of the interaction of Ni(II) with salen‐type Schiff base ligands . This family of molecules is frequently investigated because of the great variety of applications such as catalytic, industrial, optical, or medical, and various DFT studies were also carried out …”

Crystal Structure of the Bis[bis(<i>p</i>-methoxyphenyl)glyoximato]nickel(II) Complex

“…Although the continuous metal-metal coordination is weak interactions, 1 it governs the molecular arrangements of the para-normal-alkyl (-CnH2n+1) substitution series, whose metal is nickel, in both the solid (n = 1,6) 2 and mesophase (n = 12) states. 3 However, four paranormal-alkoxy (-OCmH2m+1) substitutions specifically demonstrated that the columnar geometries comprising linear metal nickel wires were broken by increasing interactions between alkoxy chains in the solid state (m ≥ 4).…”