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Genivaldo Julio Perpétuo

Publications and source records attributed to Genivaldo Julio Perpétuo.

9 recordsLinked to original sources
PubMed2005

Tetramethylammonium 2,5-dinitrophenolate monohydrate.

The crystal structure of the title compound, C4H12N+.C6H3N2O5-.H2O, is built up from tetramethylammonium cations, 2,5-dinitrophenolate anions and water molecules. The nitro groups are almost coplanar with the aryl ring, which exhibits significant distortion from an ideal hexagonal form. The X-ray geometry of the tetramethylammonium cation shows slight distortion from the tetrahedral symmetry predicted by molecular orbital calculations. The O-H...O hydrogen-bonded water and 2,5-dinitrophenolate units are related by an inversion center and form dimers. The 2,5-dinitrophenolate anions, related by an inversion center and translation, are stacked to form a column along the [100] direction.

Journal Article↗
PubMed2004

Melaminium maleate monohydrate.

In the title compound, 2,4,6-triamino-1,3,5-triazin-1-ium maleate monohydrate, C3H7N6+.C4H3O4-.H2O, containing singly protonated melaminium residues, maleate(1-) anions and water molecules, the components are linked by hydrogen bonds into a three-dimensional framework structure. The melaminium residues are connected by two pairs of N-H...N hydrogen bonds into chains in the form of stacks, with a distance of 3.26 (1) A between the triazine rings, clearly indicating pi-pi interactions. The maleate anion contains an intramolecular O-H...O hydrogen bond and the anions interact with the water molecules via O-H...O hydrogen bonds, forming zigzag chains, also in the form of stacks, in which the almost-planar maleate anions are separated by 3.26 (1) A. The experimental geometries of the ions are compared with molecular-orbital calculations of their gas-phase geometries.

Journal Article↗
PubMed2003

Anilinium monohydrogen DL-malate.

Crystals of the title salt, [(C(6)H(5)NH(3))](+).[(HOOC(CH(2))CH(OH)COO)](-) or C(6)H(8)N(+).C(4)H(5)O(5)(-), are built up from protonated anilinium residues and monodissociated DL-malate ions. The NH(3)(+) group of the anilinium cation is ordered at room temperature. Rotation of the NH(3)(+) group along the C(aromatic)-Nsp(3) bond (often observed at room temperature in other anilinium salts) is prevented by N-H.O hydrogen bonds between the NH(3)(+) group and the malate anions. The anions are connected by four O-H.O hydrogen bonds into two-dimensional sheets parallel to the (001) plane. The charged moieties, i.e. the anilinium cations and the sheets of hydrogen-bonded malate anions, form two-dimensional layers in which the phenyl rings of the anilinium residues lie perpendicular to the malate-ion sheets. The conformation of the monodissociated malate ion in the crystal is compared with that obtained from ab initio molecular-orbital calculations.

Aniline Compounds↗
PubMed2003

Bis(melaminium) DL-malate tetrahydrate.

The crystal structure of the title melaminium salt, bis(2,4,6-triamino-1,3,5-triazin-1-ium) DL-malate tetrahydrate, 2C(3)H(7)N(6)(+).C(4)H(4)O(5)(2-).4H(2)O, consists of singly protonated melaminium residues, DL-malate dianions and water molecules. The melaminium residues are connected into chains by four N-H.N hydrogen bonds, and these chains form a stacking structure along the c axis. The DL-malate dianions form hydrogen-bonded chains and, together with hydrogen-bonded water molecules, form a layer parallel to the (100) plane. The conformation of the malate ion is compared with an ab initio molecular-orbital calculation. The oppositely charged moieties, i.e. the stacks of melaminium chains and hydrogen-bonded DL-malate anions and water molecules, form a three-dimensional polymeric structure, in which N-H.O hydrogen bonds stabilize the stacking.

Journal Article↗
PubMed2002

Hexakis(melaminium) tetrakis(dihydrogenphosphate) monohydrogenphosphate tetrahydrate.

The crystal structure of the new melaminium salt, hexakis(2,4,6-triamino-1,3,5-triazin-1-ium) tetrakis(dihydrogenphosphate) monohydrogenphosphate tetrahydrate, 6C(3)H(7)N(6)(+).4H(2)PO(4)(-).HPO(4)(2-).4H(2)O, is built up from singly protonated melaminium residues, dihydrogenphosphate and monohydrogenphosphate anions, and water molecules. The melaminium residues are interconnected by four N-H...N hydrogen bonds, forming chains along the [001] direction. These chains of melaminium residues form stacks aligned along [100]. The dihydrogenphosphate anions interact with the monohydrogenphosphate anions via the H atoms and, together with hydrogen-bonded dimers of the water molecules, develop layers parallel to the (010) plane. The oppositely charged moieties interact via multiple N-H...O hydrogen bonds that stabilize the stacking structure.

Journal Article↗
PubMed2002

3-Amino-1,2,4-triazine.

In the crystal structure of 3-amino-1,2,4-triazine, C(3)H(4)N(4), the molecules form hydrogen-bonded chains that are almost parallel to the b axis (3.2 degrees), and which are inclined to the a and c axes by approximately 21 and approximately 69 degrees, respectively. The distortion of the 1,2,4-triazine ring in the crystal is compared with gas-phase ab initio molecular-orbital calculations.

Journal Article↗
PubMed2002

Melaminium glutarate monohydrate.

The crystal structure of the title new melaminium salt, 2,4,6-triamino-1,3,5-triazin-1-ium glutarate monohydrate, C(3)H(7)N(6)(+) x C(5)H(7)O(4)(-) x H(2)O, is built up from singly protonated melaminium residues, mono-dissociated glutarate ions and water molecules. The melaminium residues are interconnected by four N[bond]H...N hydrogen bonds to form chains. These chains of melaminium residues form a stacking structure. The glutarate anions form a hydrogen-bonded zigzag polymer of the form [...HOOC(CH(2))(3)COO...HOOC(CH(2))(3)COO...](n). The oppositely charged moieties, i.e. the melaminium and glutarate chains, form two-dimensional polymeric sheets. These sheets are interconnected by O[bond]H...O hydrogen bonds between the COO(-) moieties and the water molecules, and these hydrogen bonds stabilize the stacking structure.

Journal Article↗
PubMed2002

Melaminium acetate acetic acid solvate monohydrate.

The crystals of the title new melaminium salt, 2,4,6-triamino-1,3,5-triazin-1-ium acetate acetic acid solvate monohydrate, C(3)H(7)N(6)(+).CH(3)COO(-).CH(3)COOH.H(2)O, are built up from singly protonated melaminium residues, acetate anions, and acetic acid and water molecules. The melaminium residues are interconnected by N-H...N hydrogen bonds to form chains along the [010] direction. These chains of melaminium residues form stacks aligned along the a axis. The acetic acid molecules interact with the acetate anions via the H atom of their carboxylic acid groups and, together with the water molecules, form layers that are parallel to the (001) plane. The oppositely charged moieties interact via multiple N-H...O hydrogen bonds that stabilize a pseudo-two-dimensional stacking structure.

Journal Article↗