4,5-Bis(dimethylamino)quinolines: Proton Sponge versus Azine Behavior

Two first representatives, <b>5</b> and <b>6</b>, of the still unknown 4,5-bis(dimethylamino)quinoline have been synthesized and studied. While the former, being protonated either at the peri-NMe₂ groups or at the ring nitrogen, has been shown to display properties of both a proton sponge and azine, its counterpart <b>6</b> behaves exclusively as azine giving only a quinolinium salt

4,5-Bis(dimethylamino)quinolines: Proton Sponge versus Azine Behavior

Two first representatives, <b>5</b> and <b>6</b>, of the still unknown 4,5-bis(dimethylamino)quinoline have been synthesized and studied. While the former, being protonated either at the peri-NMe₂ groups or at the ring nitrogen, has been shown to display properties of both a proton sponge and azine, its counterpart <b>6</b> behaves exclusively as azine giving only a quinolinium salt

Insight into the Electronic Structure, Optical Properties, And Redox Behavior of the Hybrid Phthalocyaninoclathrochelates from Experimental and Density Functional Theory Approaches

An insight into the electronic structure of several hafnium­(IV), zirconium­(IV), and lutetium­(III) phthalocyaninoclathrochelates has been discussed on the basis of experimental UV–vis, MCD, electro- and spectroelectrochemical data as well as density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. On the basis of UV–vis and MCD spectroscopy as well as theoretical predictions, it was concluded that the electronic structure of the phthalocyninoclathrochelates can be described in the first approximation as a superposition of the weakly interacting phthalocyanine and clathrochelate substituents. Spectroelectrochemical data and DFT calculations clearly confirm that the highest occupied molecular orbital (HOMO) in all tested complexes is localized on the phthalocyanine ligand. X-ray crystallography on zirconium­(IV) and earlier reported hafnium­(IV) phthalocyaninoclathrochelate complexes revealed a slightly distorted phthalocyanine conformation with seven-coordinated metal center positioned ∼1 Å above macrocyclic cavity. The geometry of the encapsulated iron­(II) ion in the clathrochelate fragment was found to be between trigonal-prismatic and trigonal-antiprismatic

4,5-Bis(dimethylamino)quinolines: Proton Sponge versus Azine Behavior

Two first representatives, <b>5</b> and <b>6</b>, of the still unknown 4,5-bis(dimethylamino)quinoline have been synthesized and studied. While the former, being protonated either at the peri-NMe₂ groups or at the ring nitrogen, has been shown to display properties of both a proton sponge and azine, its counterpart <b>6</b> behaves exclusively as azine giving only a quinolinium salt

Exclusive Selectivity in the One-Pot Formation of C–C and C–Se Bonds Involving Ni-Catalyzed Alkyne Hydroselenation: Optimization of the Synthetic Procedure and a Mechanistic Study

A unique Ni-catalyzed transformation is reported for the one-pot highly selective synthesis of previously unknown monoseleno-substituted 1,3-dienes starting from easily available terminal alkynes and benzeneselenol. The combination of a readily available catalyst precursor, Ni­(acac)₂, and an appropriately tuned phosphine ligand, PPh₂Cy, resulted in the exclusive assembly of the <i>s-gauche</i> diene skeleton via the selective formation of C–C and C–Se bonds. The unusual diene products were stable under regular experimental conditions, and the products maintained the <i>s-gauche</i> geometry both in the solid state and in solution, as confirmed by X-ray analysis and NMR spectroscopy. Thorough mechanistic studies using ESI-MS revealed the key Ni-containing species involved in the reaction

Insight into the Electronic Structure, Optical Properties, And Redox Behavior of the Hybrid Phthalocyaninoclathrochelates from Experimental and Density Functional Theory Approaches

An insight into the electronic structure of several hafnium­(IV), zirconium­(IV), and lutetium­(III) phthalocyaninoclathrochelates has been discussed on the basis of experimental UV–vis, MCD, electro- and spectroelectrochemical data as well as density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. On the basis of UV–vis and MCD spectroscopy as well as theoretical predictions, it was concluded that the electronic structure of the phthalocyninoclathrochelates can be described in the first approximation as a superposition of the weakly interacting phthalocyanine and clathrochelate substituents. Spectroelectrochemical data and DFT calculations clearly confirm that the highest occupied molecular orbital (HOMO) in all tested complexes is localized on the phthalocyanine ligand. X-ray crystallography on zirconium­(IV) and earlier reported hafnium­(IV) phthalocyaninoclathrochelate complexes revealed a slightly distorted phthalocyanine conformation with seven-coordinated metal center positioned ∼1 Å above macrocyclic cavity. The geometry of the encapsulated iron­(II) ion in the clathrochelate fragment was found to be between trigonal-prismatic and trigonal-antiprismatic

Exclusive Selectivity in the One-Pot Formation of C–C and C–Se Bonds Involving Ni-Catalyzed Alkyne Hydroselenation: Optimization of the Synthetic Procedure and a Mechanistic Study

A unique Ni-catalyzed transformation is reported for the one-pot highly selective synthesis of previously unknown monoseleno-substituted 1,3-dienes starting from easily available terminal alkynes and benzeneselenol. The combination of a readily available catalyst precursor, Ni­(acac)₂, and an appropriately tuned phosphine ligand, PPh₂Cy, resulted in the exclusive assembly of the <i>s-gauche</i> diene skeleton via the selective formation of C–C and C–Se bonds. The unusual diene products were stable under regular experimental conditions, and the products maintained the <i>s-gauche</i> geometry both in the solid state and in solution, as confirmed by X-ray analysis and NMR spectroscopy. Thorough mechanistic studies using ESI-MS revealed the key Ni-containing species involved in the reaction