Jacqueline M. Knaust

2,5-Dimethyl­pyrazine 1,4-dioxide

The title compound, C6H8N2O2, was prepared from 2,5-dimethylpyrazine, acetic acid, and hydrogen peroxide. The 2,5-dimethylpyrazine 1,4-dioxide molecule is located on an inversion center. π–π interactions between neighboring 2,5-dimethylpyrazine 1,4-dioxide molecules are observed with an interplanar distance of 3.191 Å. Each 2,5-dimethylpyrazine 1,4-dioxide molecule is linked to four neighboring N-oxide molecules through C—H⋯O hydrogen-bonding interactions, forming two-dimensional layers.

Poly[[tris­(μ2-4,4′-bipyridine N,N′-di­oxide)hexa­nitratodieuropium(III)] dichloro­methane disolvate]

The title one-dimensional coordination network, {[Eu2(NO3)6(C10H8N2O2)3]·2CH2Cl2}n, is isostructural with the previously reported Tb and Tl coordination networks and to its Gd analog. The EuIII cation is coordinated in a distorted tricapped trigonal-prismatic fashion by nine O atoms from three bridging 4,4′-bipyridine N,N′-dioxide ligands and three chelating nitrate anions. None of the atoms lie on a special position, but there is an inversion center located between the rings of one of the ligands. The network topology is ladder-like, and each ladder interacts with six neighboring ladders through C—H⋯O hydrogen bonds. The packing motif of the ladders allows for the formation of channels that run parallel to the a axis; these channels are filled with CH2Cl2 solvent molecules that interact with the ladders through C—H⋯O hydrogen bonds.

Poly[[tetrakis(μ2-pyrazineN,N′-dioxide-κ2O:O′)holmium(III)] tris(perchlorate)]

The title three-dimensional coordination network, {[Ho(C4H4N2O2)4](ClO4)3}n, is isostructural to that of other lanthanides. The Ho+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square anti-prismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

Poly[[tetrakis(μ2-pyrazineN,N′-dioxide-κ2O:O′)erbium(III)] tris(perchlorate)]

The title three-dimensional coordination network, {[Er(C4H4N2O2)4](ClO4)3}n, is isostructural to that of other lanthanides. The Er+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) and (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

Poly[[tetrakis(μ2-pyrazineN,N′-dioxide-κ2O:O′)dysprosium(III)] tris(perchlorate)]

The title three-dimensional coordination network, {[Dy(C4H4N2O2)4](ClO4)3}n, is isostructural of other lanthanides. The Dy+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) and (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

Poly[[tetrakis(μ2-pyrazineN,N′-dioxide-κ2O:O′)neodymium(III)] tris(perchlorate)]

The title three-dimensional coordination network, {[Nd(C4H4N2O2)4](ClO4)3}n, is isostructural to that of other lanthanides. The Nd+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) and (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

Poly[[tetra­kis­(μ2-pyrazine N,N′-dioxide-κ2O:O′)neodymium(III)] tris­(perchlorate)]

The title three-dimensional coordination network, {[Nd(C4H4N2O2)4](ClO4)3}n, is isostructural to that of other lanthanides. The Nd+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) and (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

Poly[[tetra-kis-(μ(2)-pyrazine N,N'-dioxide-κO:O')dysprosium(III)] tris-(perchlorate)].

The title three-dimensional coordination network, {[Nd(C4H4N2O2)4](ClO4)3}n, is isostructural to that of other lanthanides. The Nd+3 cation lies on a fourfold roto-inversion axis. It is coordinated in a distorted square-antiprismatic fashion by eight O atoms from bridging pyrazine N,N′-dioxide ligands. There are two unique pyrazine N,N′-dioxide ligands. One ring is located around an inversion center, and there is a twofold rotation axis at the center of the other ring. There are also two unique perchlorate anions. One is centered on a twofold rotation axis and the other on a fourfold roto-inversion axis. The perchlorate anions are located in channels that run perpendicular to (001) and (110) and interact with the coordination network through C—H⋯O hydrogen bonds.

2-Methyl­pyrazine 1,4-dioxide

The title compound, C5H6N2O2, was prepared from 2-methylpyrazine, acetic acid and hydrogen peroxide. In the crystal, π–π stacking interactions between neighboring molecules are observed, with a centroid–centroid distance of 3.7370 Å, an interplanar distance of 3.167 Å, and a slippage of 1.984 Å. Each molecule is linked to four neighbors through C—H⋯O hydrogen-bonding interactions, forming one-dimensional ribbons.

1,2-Di-4-pyridylethane N,N'-dioxide-acetic acid (1/2).

The title compound, C12H12N2O2·2C2H4O2, was prepared from 1,2-di-4-pyridylethane, acetic acid, and hydrogen peroxide. The 1,2-di-4-pyridylethane N,N′-dioxide molecule is located on an inversion center. π–π stacking interactions between neighboring 1,2-di-4-pyridylethane N,N′-dioxide molecules are observed with a centroid–centroid distance of 3.613 Å, an interplanar distance of 3.317 Å, and a slippage of 1.433 Å. O—H⋯O hydrogen-bonding interactions between 1,2-di-4-pyridylethane N,N′-dioxide and acetic acid molecules result in distinct hydrogen-bonded units made of one N-oxide and two acetic acid molecules. These units are then linked into a three-dimensional network through weaker C—H⋯O hydrogen-bonding interactions.