2-[Bis(5-chloro-2-pyridylamino)methyl]pyridine monohydrate

In the title compound, the dihedral angles between the 2-amino-5-chloro­pyridyl rings and the pyridine ring are 56.26 (6)° and 78.83 (5)°; the angle between the 2-amino-5-chloro­pyridyl rings is 72.42 (5)°. The solvent water mol­ecules are linked to the organic compound by N—H⋯O, O—H⋯O, N—H⋯N and O—H⋯N hydrogen bonds. π⋯π Stacking inter­actions are also observed between the 2-amino-5-chloro­pyridyl rings (centroid⋯centroid distance = 3.243 Å)

2-(5-Bromo-2-hydroxy­phen­yl)-1,2-dihydro­quinazolin-4(3H)-one

The asymmetric unit of the title compound, C14H11BrN2O2, contains two independent mol­ecules connected into a dimer by inter­molecular N—H⋯O hydrogen bonds involving the amine and carbonyl groups. The dimers are further connected by O—H⋯O hydrogen bonds, forming chains running parallel to the a axis, which are stabilized through π–π stacking inter­actions, with a centroid–centroid distance of 3.679 (8) Å. The dihedral angle between the two aromatic rings is 89.2 (4)°

Dopaminium perchlorate

In the title compound [systematic name: 2-(3,4-dihydroxy­phen­yl)ethanaminium perchlorate], C8H12NO2 +·ClO4 −, the cations and anions are linked into three-dimensional structure via inter­molecular N—H⋯O and O—H⋯O hydrogen bonds

Tailoring dicobalt Pacman complexes of Schiff-base calixpyrroles towards dioxygen reduction catalysis

By modifying the mouth of a macrocyclic dicobalt Pacman complex, it is possible to both isolate new bridging-superoxo and hydroxyl complexes and to tune the reactivity of this system towards catalytic four-electron reduction of dioxygen to water.</p

Ligand Modifications for Tailoring the Binuclear Microenvironments in Schiff-Base Calixpyrrole Pacman Complexes

The synthesis and structures of two new octadentate, Schiff-base calixpyrrole macrocycles are presented in which modifications at the meso-substituents (L-1) or the aryl spacer between the two pyrrole-imine donor compartments (L-2) are introduced. The outcomes of these changes are highlighted in the structures of binuclear Pacman complexes of these macrocycles, [M-2(L-1)] and [M-2(L-2)]. Both palladium and cobalt complexes of the fluorenyl-meso-substituted macrocycle H4L1 adopt rigid, but laterally twisted geometries with enclosed bimetallic microenvironments; a consequence of this spatial constraint is an exo-exo-bonding mode of pyridine in the dicobalt complex [Co-2(py)(2)(L-1)]. In contrast, the use of an anthracenyl backbone between the two donor compartments (H4L2) generates a binuclear palladium complex in which the two PdN4 environments are approximately cofacial and separated by 5.3 angstrom, so generating a bimetallic complex that is structurally very similar to binuclear compounds of cofacial diporphyrins.</p

Tailoring dicobalt Pacman complexes of Schiff-base calixpyrroles towards dioxygen reduction catalysis

By modifying the mouth of a macrocyclic dicobalt Pacman complex, it is possible to both isolate new bridging-superoxo and hydroxyl complexes and to tune the reactivity of this system towards catalytic four-electron reduction of dioxygen to water.</p

Ligand Modifications for Tailoring the Binuclear Microenvironments in Schiff-Base Calixpyrrole Pacman Complexes

The synthesis and structures of two new octadentate, Schiff-base calixpyrrole macrocycles are presented in which modifications at the meso-substituents (L-1) or the aryl spacer between the two pyrrole-imine donor compartments (L-2) are introduced. The outcomes of these changes are highlighted in the structures of binuclear Pacman complexes of these macrocycles, [M-2(L-1)] and [M-2(L-2)]. Both palladium and cobalt complexes of the fluorenyl-meso-substituted macrocycle H4L1 adopt rigid, but laterally twisted geometries with enclosed bimetallic microenvironments; a consequence of this spatial constraint is an exo-exo-bonding mode of pyridine in the dicobalt complex [Co-2(py)(2)(L-1)]. In contrast, the use of an anthracenyl backbone between the two donor compartments (H4L2) generates a binuclear palladium complex in which the two PdN4 environments are approximately cofacial and separated by 5.3 angstrom, so generating a bimetallic complex that is structurally very similar to binuclear compounds of cofacial diporphyrins.</p