Discovering the Complex Chemistry of a Simple Ni^II/H₃L System: Magnetostructural Characterization and DFT Calculations of Di- and Polynuclear Nickel(II) Compounds

Abstract

The simple nickel(II) acetate/H(3)L system (H(3)L = 2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) presents an unusually complicated reactivity scheme, which strongly depends on the Ni(OAc)(2)/H(3)L molar ratio and on the pH of the medium. Thus, in addition to the formerly reported compounds [Ni(2)L(OAc)(H(2)O)(2)][Ni(2)L(OAc)(H(2)O)(HOAc)].3.25H(2)O, 1.3.25H(2)O; [{Ni(3)L(OAc)(OH)(H(2)O)(MeOH)(2)}(CO(3)){Ni(2)L(OAc)(MeOH)(2)}].2.7H(2)O.1.5MeOH, 2.2.7H(2)O.1.5MeOH; and [Ni(3)L(OAc)(2)(OH)(H(2)O)(MeOH)(2)].3H(2)O.0.5MeOH, 3.3H(2)O.0.5MeOH, this system can also yield some other complexes as [Ni(2)L(o-O-C(6)H(4)-CHO)(H(2)O)].1.75H(2)O, 4.1.75H(2)O; [Ni(2)L(OH)(H(2)O)(MeOH)].3H(2)O.1.5MeOH, 5.3H(2)O.1.5MeOH; [Ni(2)L(OAc)(MeOH)(2)].H(2)O.3MeOH, 6.H(2)O.3MeOH; and [{Ni(2)L(MeOH)}(CO(3)){Ni(2)L(MeOH)(2)}].4.75H(2)O.2MeOH, 7.4.75H(2)O.2MeOH. A detailed study of the reaction scheme that allows obtaining all of these complexes is presented herein, as well as the structural characterization of the novel compounds 4.1.75H(2)O to 7.4.75H(2)O.2MeOH. X-ray analyses show that all of them present stereoisomery in the solid state. In this way, 6.H(2)O.3MeOH appears particularly interesting, as its molecular and supramolecular chirality is only controlled by hydrogen bonds. Magnetic studies of 5.3H(2)O to 7.4.75H(2)O.2MeOH are also discussed, and the complicated magnetic superexchange pathway shown by 7.4.75H(2)O.2MeOH is analyzed in light of DFT calculations.

2D Supramolecular Structure for a Chiral Heterotrinuclear ZnII2HoIII Complex through Varied HBonds Connecting Solvates and Counterions

“…Despite the high stability shown by this type of three-armed ligands when we had worked with them ( [11,12] and own references therein), the reason for these fruitless results could be related to reaction and/or crystallisation periods longer than usual, with a partial decomposition of H3L. This fact had been previously detected for another related ligand [18]. Unfortunately, the lack of a sufficient amount of sample, with a guaranteed purity, prevented us from performing further studies of this complex.…”

μ-Acetato-μ-(5-chloro-2-{1,3-bis[2-(5-chloro-2-oxidobenzylideneamino)ethyl]imidazolidin-2-yl}phenolato)-bis[methanolnickel(II)] methanol monosolvate monohydrate

“…For dinuclear nickel compounds containing ligands with a predefined ground state, see: Fondo et al (2005Fondo et al ( , 2007Fondo et al ( , 2009 ; ;; Lu et al (2007); Paital et al (2007Paital et al ( , 2009. For density functional theory (DFT) calculations, see: Fondo et al (2005).…”

“…Nickel complexes of the compartmental triprotic heptadentate ligand, 2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine and its derivatives have been of interest for their ability to give rise to dinuclear compounds with a predefined ground state (Fondo et al, 2005(Fondo et al, , 2007(Fondo et al, , 2009Lu et al, 2007;Paital, et al, 2007Paital, et al, , 2009. Density functional theory (DFT) calculations demonstrated that the Schiff base provides an NCN bridge between the metal ions that helps to mediate the ferromagnetic exchange (Fondo, et al, 2005).…”

μ-Acetato-aqua-μ-(5-bromo-2-{1,3-bis[2-(5-bromo-2-oxidobenzylideneamino)ethyl]imidazolidin-2-yl}phenolato)methanoldinickel(II) methanol disolvate monohydrate

“…For nickel complexes of similar ligands, see: Fondo et al (2005Fondo et al ( , 2006aFondo et al ( ,b, 2007Fondo et al ( , 2009 ;Khan et al (2011); Lu et al (2007); Paital et al (2007Paital et al ( , 2009).…”

“…Data collection: SMART (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL. compounds with a predefined ground state (Fondo et al, 2005(Fondo et al, , 2006a(Fondo et al, ,b, 2007(Fondo et al, , 2009Lu et al, 2007;Paital, et al, 2007Paital, et al, , 2009). Density functional theory (DFT) calculations demonstrated that the Schiff base provides an NCN bridge between the metal ions that helps to mediate the ferromagnetic exchange (Fondo, et al, 2005).…”