Diastereomeric Ni(II) Schiff-base cysteine derivatives: Non-covalent interactions and redox activity

Fine‐Tuning Redox Properties of Heteroleptic Molybdenum Complexes through Ligand‐Ligand‐Cooperativity

“…Switching off the dispersion correction during the geometry relaxation of 2 1− resulted in a structure without NCI in the second coordination sphere (Figure S12). The difference in energy for 2 1− was calculated to be 2.4 kcal mol −1 lower for the “stacked” structure, which is in accordance with similar intramolecular London dispersion forces [11b] . The most significant degree of stabilization of the “stacked” structure is seen when both ligands are aromatic ( 2 1− ) and decreases with the gradual replacement of the arene groups by cyclohexyl‐derived moieties ( 3 1− : 1.7 kcal mol −1 ; 4 1− : 1.1 kcal mol −1 ; 5 1− : 1.2 kcal mol −1 ) just as the degree of dithiolene bending does.…”

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

“…To choose the most promising candidates for electrochemical three-membered ring opening, a voltammetric study was performed. As it has been shown in our previous publications [49][50][51], the electrochemical behavior and the orbitals location sites are dependent on the type of the amino acid involved in the Schiff base complex. The LUMOs of the glycine, alanine, serine and cysteine derivatives are formed as an antibonding combination of the Ni d x²-y² orbital with the group orbitals of the ligands; the π* orbital of the imine and the π orbital of the phenylene fragments are also partially involved.…”

Feinabstimmung der Redoxeigenschaften von heteroleptischen Molybdän‐Komplexen mittels Ligand‐Ligand‐Kooperativität

“…Das Ausschalten der Dispersionskorrektur während der Geometrieoptimierung von 2 1− führte hingegen zu einer Struktur ohne NCI in der zweiten Koordinationssphäre (Abbildung S12). Die entsprechende Energiedifferenz wurde für 2 1− zu einer um 2.4 kcal mol −1 niedrigeren Energie für die “gestapelte” Struktur berechnet, was mit vergleichbaren intramolekularen Dispersionskräften für Stapelwechselwirkungen übereinstimmt [11b] . Die ausgeprägteste Stabilisierung der “gestapelten” Struktur ist zu beobachten, wenn beide Liganden aromatisch sind ( 2 1− ); sie nimmt mit dem konsekutiven Ersatz der Arengruppen durch Cyclohexylgruppen ( 3 1− : 1.7 kcal mol −1 ; 4 1− : 1.1 kcal mol −1 ; 5 1− :1.2 kcal mol −1 ) ab, ebenso wie der Grad des Abknickens des Dithiolenliganden.…”