Showing papers in "Acta Crystallographica Section C-crystal Structure Communications in 2007"
TL;DR: The structure of the title compound consists of distorted B12 icosahedra linked by N-B-N chains and the main feature of the structure is that the 3b position is occupied by the B atom, which makes the structure different from those of B(6)O, for which these atom sites are vacant.
Abstract: The structure of the title compound consists of distorted B12 icosahedra linked by N—B—N chains. The compound crystallizes in the rhombohedral space group R\overline{3}m (No. 166). The unit cell contains four symmetry-independent atom sites, three of which are occupied by boron [in the 18h, 18h (site symmetry m) and 3b (site symmetry \overline{3}m) Wyckoff positions] and one by nitrogen (in the 6c Wyckoff position, site symmetry 3m). Two of the B atoms form the icosahedra, while N atoms link the icosahedra together. The main feature of the structure is that the 3b position is occupied by the B atom, which makes the structure different from those of B6O, for which these atom sites are vacant, and B4+xC1−x, for which this position is randomly occupied by both B and C atoms.
98 citations
TL;DR: The title compounds, (E)-2-[(2-bromophenyl)iminomethyl]-4-methoxyphenol, C(14)H(12)BrNO(2), (I), (E-2)[(3-bROMophenyl]iminometrichyl], and (III), adopt the phenol-imine tautomeric form and there are strong intramolecular O-H...N hydrogen bonds.
Abstract: The title compounds, (E)-2-[(2-bromophenyl)iminomethyl]-4-methoxyphenol, C(14)H(12)BrNO(2), (I), (E)-2-[(3-bromophenyl)iminomethyl]-4-methoxyphenol, C(14)H(12)BrNO(2), (II), and (E)-2-[(4-bromophenyl)iminomethyl]-4-methoxyphenol, C(14)H(12)BrNO(2), (III), adopt the phenol-imine tautomeric form. In all three structures, there are strong intramolecular O-H...N hydrogen bonds. Compound (I) has strong intermolecular hydrogen bonds, while compound (III) has weak intermolecular hydrogen bonds. In addition to these intermolecular interactions, C-H...pi interactions in (I) and (III), and pi-pi interactions in (I), play roles in the crystal packing. The dihedral angles between the aromatic rings are 15.34 (12), 6.1 (3) and 39.2 (14) degrees for (I), (II) and (III), respectively.
49 citations
TL;DR: The title compound, (+)-(S)-3-[5-cyano-2-(4-fluorophenyl)-1,3-dihydroisobenzofuran-2yl]propanaminium oxalate oxalic acid 0.325-hydrate, is a molecular salt of the N-protonated escitalopram cation.
Abstract: The title compound {systematic name: (+)-(S)-3-[5-cyano-2-(4-fluorophenyl)-1,3-dihydroisobenzofuran-2yl]propanaminium oxalate oxalic acid 0.325-hydrate}, 2C20H22FN2O+·C2O42−·C2H2O4·0.325H2O, is a molecular salt of the N-protonated escitalopram cation. As well as charge-balancing oxalate dianions, neutral molecules of oxalic acid are present. The component species interact by way of N—H⋯O and short O—H⋯O hydrogen bonds, resulting in supramolecular chains.
47 citations
TL;DR: The crystal structures of both compounds are stabilized by intricate three-dimensional hydrogen-bonding networks and alternate hydrophobic and hydrophilic layers are observed as a result of a column-like arrangement of the anions and the aromatic rings of the cations.
Abstract: In the title compounds, 4-carboxyanilinium (2R,3R)-tartrate, C7H8NO2+·C4H5O6−, (I), and 4-aminobenzoic acid, C7H7NO2, (II), the carboxyl planes of the 4-carboxyanilinium cations/4-aminobenzoic acid are twisted from the aromatic plane. In (I), the characteristic head-to-tail interactions are observed through the tartrate anions, forming two C22(7) chain motifs propagating parallel to the a and c axes of the unit cell. Also, the tartrate anions are connected through two primary C11(6) and C11(7) chain motifs, leading to a secondary R44(22) ring motif. In (II), head-to-tail interaction is seen through a discrete D11(2) motif and carboxyl group dimerization is observed through centrosymmetrically related R22(8) motifs around the inversion centres of the unit cell. The crystal structures of both compounds are stabilized by intricate three-dimensional hydrogen-bonding networks. Alternate hydrophobic and hydrophilic layers are observed in (I) as a result of a column-like arrangement of the anions and the aromatic rings of the cations.
38 citations
TL;DR: The ELMAM refinement of the standard independent atom model shows a good improvement of the statistical indices compared with the IAM model, notably in terms of thermal displacement parameters and bond distances involving H atoms.
Abstract: The crystal structure of l-aspartic acid, C4H7NO4, has been determined using two types of refinement, viz. the standard independent atom model (IAM) and the experimental library multipolar atom model (ELMAM). The ELMAM refinement shows a good improvement of the statistical indices compared with the IAM model, notably in terms of thermal displacement parameters and bond distances involving H atoms.
33 citations
TL;DR: The crystal structures in two solid phases of the title compound [phenazine-chloranilic acid (1/1), C12H8N2.C6H2Cl2O4], have been determined and each structure was refined as an inversion twin.
Abstract: The crystal structures in two solid phases, i.e. phase II stable between 146 and 253 K and phase IV below 136 K, of the title compound [phenazine-chloranilic acid (1/1), C12H8N2 center dot C6H2Cl2O4, in phase II, and phenazinium hydrogen chloranilate, C12H9N2+center dot C6HCl2O4-, in phase IV], have been determined. Both phases crystallize in P2(1), and each structure was refined as an inversion twin. In phase II, the phenazine and chloranilic acid molecules are arranged alternately through two kinds of O-H center dot center dot center dot N hydrogen bonds. In phase IV, salt formation occurs by donation of one H atom from the chloranilic acid molecule to the phenazine molecule; the resulting monocation and monoanion are linked by N-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds.
25 citations
TL;DR: Polymorph VI of 4-amino-N-(2-pyridyl)benzenesulfonamide is monoclinic (space group P2(1)/n), the asymmetric unit contains two different tautomeric forms which form two separate two- and three-dimensional hydrogen-bonded networks which interpenetrate.
Abstract: Polymorph VI of 4-amino-N-(2-pyridyl)benzenesulfonamide, C11H11N3O2S, is monoclinic (space group P21/n). The asymmetric unit contains two different tautomeric forms. The structure displays N—H⋯N and N—H⋯O hydrogen bonding. The two independent molecules form two separate two- and three-dimensional hydrogen-bonded networks which interpenetrate. The observed patterns of hydrogen bonding are analogous to those in polymorph I of sulfathiazole.
22 citations
TL;DR: The structure of C10H13ClN2O3S is monoclinic, in contrast with the two previously described ortho-rhomm-bic α- and β-polymorphs as mentioned in this paper.
Abstract: The structure of a new polymorph of the title compound, C10H13ClN2O3S, known as the antidiabetic drug chlorpropamide, is monoclinic, in contrast with the two previously described orthorhombic α- and β-forms. The molecules in the γ-polymorph are linked into bands by hydrogen bonds similar to those in the α-polymorph. The conformation of the molecules in the γ-form is close to that in the β-polymorph.
22 citations
TL;DR: In both compounds, layers of centrosymmetric hydrogen-bonded dimers are developed in the [-5 -2 22] plane through C-H...O interactions, involving both carbonyl groups as acceptors, developing the three-dimensional structure along the c axis.
Abstract: The title compounds, C12H9ClO4, (I), and C12H9BrO4, (II), are isomorphous and crystallize in the monoclinic space group P21/c. Both compounds present an anti conformation between the 3-carboxy and the lactone carbonyl groups. Both carbonyl groups are out of the plane defined by the remaining chromene atoms, by 8.37 (6) and 17.57 (6)° for (I), and by 9.07 (8) and 18.96 (18)° for (II), owing to their involvement in intermolecular interactions. In both compounds, layers of centrosymmetric hydrogen-bonded dimers are developed in the [\overline{5} \overline{2} 22] plane through C—H⋯O interactions, involving both carbonyl groups as acceptors. Two families of dimers stack through C=O⋯C=O, C=O⋯π and C—X⋯C=O (X = Cl and Br) dipolar interactions, as well as a C—H⋯π interaction, developing the three-dimensional structure along the c axis.
21 citations
TL;DR: The structure of diyttrium digermanate in the tetragonal space group P4(3)2(1)2 has been determined in this paper, where the basic units of the structure are isolated Ge(2)O(7) groups, sharing one common O atom and displaying a Ge-O-Ge angle of 134.9 (3) degrees.
Abstract: The structure of diyttrium digermanate, Y(2)Ge(2)O(7), has been determined in the tetragonal space group P4(3)2(1)2. It contains one Y, one Ge (both site symmetry 1 on general position 8b) and four O atoms [one on special position 4a (site symmetry ..2) and the remaining three on general positions 8b]. The basic units of the structure are isolated Ge(2)O(7) groups, sharing one common O atom and displaying a Ge-O-Ge angle of 134.9 (3) degrees , and infinite helical chains of pentagonal YO(7) dipyramids, parallel to the 4(3) screw axis. The crystal investigated here represents the left-handed form of the tetragonal R(2)Ge(2)O(7) compounds (R = Eu(3+), Tb(3+), Er(3+), Tm(3+) and Lu(3+)).
20 citations
TL;DR: In this article, a detailed procedure for the synthesis of Bi5O7Br is given, and the structure is compared with the closely related Ibca structure of α-Bi 5O7I.
Abstract: Pentabismuth heptoxide bromide, Bi5O7Br, crystallizes in the space group Cmca. Its structure is compared with the closely related Ibca structure of α-Bi5O7I. The change in the space group is assumedly the result of a compromise between the different spatial needs of Br and I and the rigidity of the {3∞}[Bi, O] frameworks into which they are embedded. A detailed procedure for the synthesis of Bi5O7Br is given.
TL;DR: The crystal structure of the title compound, H(2)O, is described in terms of two-dimensional supramolecular arrays built up from infinite chains assembled via N-H…O and O-H...O hydrogen bonds among the organic molecules and solvent water molecules.
Abstract: The crystal structure of the title compound, C10H10N2O2·H2O, also known as l-5-benzylhydantoin monohydrate, is described in terms of two-dimensional supramolecular arrays built up from infinite chains assembled via N—H⋯O and O—H⋯O hydrogen bonds among the organic molecules and solvent water molecules, with graph-set R33(10)C(5)C22(6). The hydrogen-bond network is reinforced by stacking of the layers through C—H⋯π interactions.
TL;DR: The structures of five metal complexes containing the 4-oxo-4H-pyran-2,6-dicarboxylate dianion illustrate the remarkable coordinating versatility of this ligand and the great structural diversity of its complexes.
Abstract: The structures of five metal complexes containing the 4-oxo-4H-pyran-2,6-dicarboxylate dianion illustrate the remarkable coordinating versatility of this ligand and the great structural diversity of its complexes. In tetraaquaberyllium 4-oxo-4H-pyran-2,6-dicarboxylate, [Be(H2O)4](C7H2O6), (I), the ions are linked by eight independent O—H⋯O hydrogen bonds to form a three-dimensional hydrogen-bonded framework structure. Each of the ions in hydrazinium(2+) diaqua(4-oxo-4H-pyran-2,6-dicarboxylato)calcate, (N2H6)[Ca(C7H2O6)2(H2O)2], (II), lies on a twofold rotation axis in the space group P2/c; the anions form hydrogen-bonded sheets which are linked into a three-dimensional framework by the cations. In bis(μ-4-oxo-4H-pyran-2,6-dicarboxylato)bis[tetraaquamanganese(II)] tetrahydrate, [Mn2(C7H2O6)2(H2O)8]·4H2O, (III), the metal ions and the organic ligands form a cyclic centrosymmetric Mn2(C7H2O6)2 unit, and these units are linked into a complex three-dimensional framework structure containing 12 independent O—H⋯O hydrogen bonds. There are two independent CuII ions in tetraaqua(4-oxo-4H-pyran-2,6-dicarboxylato)copper(II), [Cu(C7H2O6)(H2O)4], (IV), and both lie on centres of inversion in the space group P\overline{1}; the metal ions and the organic ligands form a one-dimensional coordination polymer, and the polymer chains are linked into a three-dimensional framework containing eight independent O—H⋯O hydrogen bonds. Diaqua(4-oxo-4H-pyran-2,6-dicarboxylato)cadmium monohydrate, [Cd(C7H2O6)(H2O)2]·H2O, (V), forms a three-dimensional coordination polymer in which the organic ligand is coordinated to four different Cd sites, and this polymer is interwoven with a complex three-dimensional framework built from O—H⋯O hydrogen bonds.
TL;DR: The Schiff base compound, C(28)H(26)N(2)O(2), possesses both OH and NH tautomeric character in its molecular structure as discussed by the authors.
Abstract: The title Schiff base compound, C(28)H(26)N(2)O(2), possesses both OH and NH tautomeric character in its molecular structure While the OH side of the compound is described as an intermediate state, its NH side adopts a predominantly zwitterionic form The molecular structure of the compound is stabilized by both N(+)-HO(-) and O-HN intramolecular hydrogen bonds There are two weak C-HO hydrogen bonds leading to polymeric chains of topology C(5) and C(13) running along the b axis of the unit cell In addition, intermolecular C-Hpi interactions serve to stabilize the extended structure
TL;DR: 4-Aminobenzoic acid (PABA) residues are arranged on both sides of the proline aggregate and are connected through water O atoms, which act as acceptors for PABA and as hydrogen-bond donors to the amino acids.
Abstract: The title adduct, 4-aminobenzoic acid-L-proline-water (1/2/1), C(7)H(7)NO(2).2C(5)H(9)NO(2).H2O, contains two independent proline chains with a C(5) motif, each of the head-to-tail type and each held together by N-H...O hydrogen bonds, propagated parallel to the b and c axes of the unit cell. Thus, the proline residues aggregate parallel to the ac plane. 4-Aminobenzoic acid (PABA) residues are arranged on both sides of the proline aggregate and are connected through water O atoms, which act as acceptors for PABA and as hydrogen-bond donors to the amino acids. The characteristic features of PABA, viz. twisting of the carboxyl plane from the aromatic ring and the formation of a head-to-tail chain motif [C(8)] along the b axis, are observed. A distinct feature of the structure is that no proton transfer occurs between proline and PABA.
TL;DR: This analysis confirms the atomic positions of methyl H atoms of the solvent molecules that were inferred from the X-ray data and provides a useful tool for structure validation.
Abstract: Bendroflumethiazide, or 3-benzyl-6-(trifluoromethyl)-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide, is reported to crystallize as 1:1 solvates with acetone, C15H14F3N3O4S2·C3H6O, and N,N-dimethylformamide, C15H14F3N3O4S2·C3H7NO. A detailed investigation of the crystal packing and intermolecular interactions is presented by means of Hirshfeld surface analysis. This analysis confirms the atomic positions of methyl H atoms of the solvent molecules that were inferred from the X-ray data and provides a useful tool for structure validation.
TL;DR: The crystal structure of hydrothermally synthesized caesium aluminium bis[dihydrogen arsenate(V)] hydrogen arsenate (V), CsAl(H(2)AsO(4))(2)(HAsO4)), was determined from single-crystal X-ray diffraction data collected at room temperature as mentioned in this paper.
Abstract: The crystal structure of hydrothermally synthesized caesium aluminium bis[dihydrogen arsenate(V)] hydrogen arsenate(V), CsAl(H(2)AsO(4))(2)(HAsO(4)), was determined from single-crystal X-ray diffraction data collected at room temperature. The compound represents a new structure type that is characterized by decorated krohnkite-like [100] chains of corner-sharing AlO(6) octahedra and AsO(4) tetrahedra. Ten-coordinated Cs atoms are situated between the chains, which are interconnected by five different hydrogen bonds [O...O = 2.569 (4)-2.978 (4) A]. All atoms are in general positions. CsAl(H(2)AsO(4))(2)(HAsO(4)) is very closely related to CsGa(H(1.5)AsO(4))(2)(H(2)AsO(4)) and isotypic CsCr(H(1.5)AsO(4))(2)(H(2)AsO(4)).
TL;DR: Er(C6H11NO)8][Cr(NCS)6 is a new structure type for [Ln(∊-caprolactam)8] where Ln is a lanthanide.
Abstract: The title compound, [Er(C6H11NO)8][Cr(NCS)6], is a new structure type for [Ln(∊-caprolactam)8][Cr(NCS)6], where Ln is a lanthanide. There are two independent cations and two independent anions in the asymmetric unit. The Er atom is in a distorted square-antiprismatic environment of eight O atoms of the organic ligands; Er—O bond distances are in the range 2.29–2.44 A. The coordination environment of the Cr atom is a slightly distorted octahedron; Cr—N bond distances vary from 1.99 to 2.01 A. The mutual packing of the cations and the anions follows a distorted NaCl motif. One cation has the Er atom on a twofold axis and one of the anions has the Cr atom on a twofold axis.
TL;DR: In single crystals of a new monoclinic (C2/m) form of tricopper(II) diselenium(IV) dichloride hexaoxide, Cu3(SeO3)2Cl2, the Se atom is in the 4i position, while the two Cu atoms are in 2a and 4i positions.
Abstract: Monoclinic Cu3(SeO3)(2)Cl2: an oxohalide with an unusual CuO4Cl trigonal-bipyramidal coordination
TL;DR: The crystal structures of the two organic-inorganic hybrids bis(4-aminopyridinium) hexachloridostannate(IV), (C(5)H(7)N(2))(2%)(2)[SnCl(6)], and bis(p-toluid inium)hexachlorideostannates(IV) differ in the way their cations pack in the layered structures.
Abstract: The crystal structures of the two organic-inorganic hybrids bis(4-aminopyridinium) hexachloridostannate(IV), (C(5)H(7)N(2))(2)[SnCl(6)], and bis(p-toluidinium) hexachloridostannate(IV), (C(7)H(10)N)(2)[SnCl(6)], differ in the way their cations pack in the layered structures. The Sn atom in the 4-aminopyridinium compound lies on an inversion centre.
TL;DR: The structure of 2,2,2-2-trinitro-ethanol, C2H3N3O7, at 100'2'K has Z' = 2 in the space group P21/c.
Abstract: 2,2,2-Trinitroethanol, C2H3N3O7, at 100 (2) K has Z′ = 2 in the space group P21/c. The structure displays intramolecular O—H⋯O hydrogen bonds, as well as intermolecular O—H⋯O and C—H⋯O hydrogen bonding; the O—H⋯O hydrogen bonds, forming R44(8) rings, and dipolar nitro–nitro interactions account for the high density of 1.839 Mg m−3.
TL;DR: In the crystal structures of the two imidazole derivatives 5-chloro-1,2-dimethyl-4-nitro-1H-imidazoles, C(5)H(6)ClN(3)O(2), (I), and 2-chlorosine-1-methyl- 4-nitrogen-2- methyl-3- chloro- 1-Methine-4 (I) (II), C-Cl...
Abstract: In the crystal structures of the two imidazole derivatives 5-chloro-1,2-dimethyl-4-nitro-1H-imidazole, C5H6ClN3O2, (I), and 2-chloro-1-methyl-4-nitro-1H-imidazole, C4H4ClN3O2, (II), C—Cl⋯O halogen bonds are the principal specific interactions responsible for the crystal packing. Two different halogen-bond modes are observed: in (I), there is one very short and directional C—Cl⋯O contact [Cl⋯O = 2.899 (1) A], while in (II), the C—Cl group approaches two different O atoms from two different molecules, and the contacts are longer [3.285 (2) and 3.498 (2) A] and less directional. In (I), relatively short C—H⋯O hydrogen bonds provide the secondary interactions for building the crystal structure; in (II), the C—H⋯O contacts are longer but there is a relatively short π–π contact between molecules related by a centre of symmetry. The molecule of (I) is almost planar, the plane of the nitro group making a dihedral angle of 6.97 (7)° with the mean plane of the imidazole ring. The molecule of (II) has crystallographically imposed mirror symmetry and the nitro group lies in the mirror plane.
TL;DR: In the crystal structures of the title compounds, C(6)H(10)N(3)O(2)+.C(7)H (4)NO(4) NO(4)-.H2O, (I), C-H...O hydrogen bonds are observed and the water molecule plays a pivotal role, and five hydrogen-bonded fused rings are formed around the water molecules.
Abstract: In the crystal structures of the title compounds, C(6)H(10)N(3)O(2)+.C(7)H(5)O(3)-.H2O, (I), C(6)H(10)N(3)O(2)+.C(7)H(4)NO(4)-.H2O, (II), and C(6)H(10)N(3)O(2)+.C(4)H(5)O(6)-.C(6)H(9)N(3)O(2), (III), the 2-amino-4,6-dimethoxypyrimidinium cation [abbreviated as (MeO)2-Hampy+] interacts with the carboxylate group of the corresponding anion through a pair of nearly parallel N-H...O hydrogen bonds to form R(2)(2)(8) ring motifs. In (I), the (MeO)2-Hampy+ cation is centrosymmetrically paired through a pair of N-H...N hydrogen bonds involving the 2-amino group and a ring N atom forming an R(2)(2)(8) motif. In (II), inversion-related R(2)(2)(8) motifs (amino-pyrimidine-carboxylate motifs) are further bridged by N-H...O hydrogen bonds on either side forming a DDAA array of quadruple hydrogen bonds. This array is extended further on either side by O(water)-H...O(methoxy) hydrogen bonds, resulting in an array of six hydrogen bonds (ADDAAD). The water molecule plays a pivotal role, and five hydrogen-bonded fused rings are formed around the water molecule. In (III), the carboxy group of the tartrate anion interacts with the ring N atom and 2-amino group of the neutral (MeO)2-ampy molecule through N-H...O and O-H...N hydrogen bonds. There is also an intramolecular O-H...O hydrogen bond in the tartrate anion. In all three crystal structures, C-H...O hydrogen bonds are observed.
TL;DR: Significant pi-pi stacking interactions are also observed between aromatic rings of amitriptyline and picrate, and these, combined with the C-H...pi interactions, associate molecules into linear arrays along the [111] direction.
Abstract: In the structure of the title salt [systematic name: 3-(10,11-dihydro-5H-dibenzo[a,d][7]annulen-5-ylidene)-N,N-dimethylpropan-1-aminium 2,4,6-trinitrophenolate] of a tricyclic antidepressant, C(20)H(24)N+.C(6)H(2)N(3)O(7)-, the dimethylaminopropyl subunit possesses a classical static conformational disorder. The central cycloheptadiene ring adopts a bent conformation that is intermediate between boat and chair forms, leading to a butterfly shape for the hetero-tricyclic moiety. In a complementary fashion, donors from amitriptyline and acceptors from picrate form intermolecular C-H...O hydrogen bonds and N-H...O salt bridges. These hydrogen bonds cluster amitriptyline and picrate ions into a closed R4(4)(36) hetero-tetramer, whereas intermolecular C-H...pi interactions between amitriptyline ions cluster them into homo-dimers. Significant pi-pi stacking interactions are also observed between aromatic rings of amitriptyline and picrate, and these, combined with the C-H...pi interactions, associate molecules into linear arrays along the [111] direction.
TL;DR: In this article, the Sr(II) ion is located on a twofold rotation axis and assumes a distorted square-antiprism SrN4O4 coordination geometry, formed by two phenanthroline (phen) ligands, two 2-hydroxybenzoate anions and two water molecules.
Abstract: In the title compound, [Sr(C7H5O3)2(C12H8N2)2(H2O)2], the Sr(II) ion is located on a twofold rotation axis and assumes a distorted square-antiprism SrN4O4 coordination geometry, formed by two phenanthroline (phen) ligands, two 2-hydroxybenzoate anions and two water molecules. Within the mononuclear complex molecule, intramolecular pi-pi stacking is observed between nearly parallel coordinated phen ligands, while normal intermolecular pi-pi stacking occurs between parallel phen ligands of adjacent complex molecules. Classic O-H...O and weak C-H...O hydrogen bonding helps to stabilize the crystal structure.
TL;DR: The asymmetric unit of the amino-oxo tautomer of 5-formyluracil, C(5)H(4)N(2)O(3), comprises one planar amino-oxide tautomers, as every atom in the structure lies on a crystallographic mirror plane.
Abstract: The asymmetric unit of the amino-oxo tautomer of 5-formyluracil (systematic name: 2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carbaldehyde), C(5)H(4)N(2)O(3), comprises one planar amino-oxo tautomer, as every atom in the structure lies on a crystallographic mirror plane. At variance with all the previously reported small-molecule crystal structures containing the 5-formyluracil residue, the formyl substituent in the title compound exhibits an unusual syn conformation. The molecules are linked into planar sheets parallel to the bc plane by a combination of six N-H...O and C-H...O hydrogen bonds. Four of the hydrogen bonds are utilized to stabilize the formyl group in the syn conformation.
TL;DR: The protonation occurs at the ring N atoms and the bond distances in the protonated molecules indicate significant bond alterations, consistent with charge-separated polar forms.
Abstract: In the 1:1 monohydrated molecular adduct 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride 2,4-diamino-6-methyl-1,3,5-triazine monohydrate, C(4)H(8)N(5)(+).Cl(-).C(4)H(7)N(5).H(2)O, formed between 2,4-diamino-6-methyl-1,3,5-triazin-1-ium chloride (acetoguanaminium chloride) and 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), and in triaminopyrimidinediium dichloride dihydrate, C(4)H(9)N(5)(2+).2Cl(-).2H(2)O, whose cationic component lies across a twofold rotation axis, the protonation occurs at the ring N atoms and the bond distances in the protonated molecules indicate significant bond alterations, consistent with charge-separated polar forms. The supramolecular structures of both compounds are stabilized by systems of hydrogen bonds forming complex sheets, interlinked by sets of hydrogen bonds involving the solvent water molecules and the chloride anions.
TL;DR: The crystal structures of the two isomers bis(1-phenylethylammonium) hexachloridostannate(IV) and bis(2-phenYL(12)N)(2)[SnCl(6)], exhibit alternating organic and inorganic layers, which interact via N-H...Cl hydrogen bonding.
Abstract: The crystal structures of the two isomers bis(1-phenylethylammonium) hexachloridostannate(IV) and bis(2-phenylethylammonium) hexachloridostannate(IV), both (C8H12N)2[SnCl6], exhibit alternating organic and inorganic layers, which interact via N—H⋯Cl hydrogen bonding. The inorganic layer contains an extended two-dimensional hydrogen-bonded sheet. The Sn atom in the 1-phenylethylammonium salt lies on an inversion centre.
TL;DR: In the first title salt, [Cu(C12H8N2)2(C5H10N2Se)](ClO4)2, the CuII centre occupied a distorted trigonal-bipyramidal environment defined by four N donors from two 1,10-phenanthroline (phen) ligands and by the Se donor of a 1,3-dimethyl-imidazolidine-2-selone ligand, with the equatorial plane defined by the N and by two donors from different phen ligands as discussed by the authors.
Abstract: In the first title salt, [Cu(C12H8N2)2(C5H10N2Se)](ClO4)2, the CuII centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10-phenanthroline (phen) ligands and by the Se donor of a 1,3-dimethylimidazolidine-2-selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) A and the Cu—Se distance is 2.491 (3) A. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C10H8N2)2(C3H6N2S)](ClO4)2, the CuII centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′-bipyridyl (bipy) ligands and an S donor from an imidazolidine-2-thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) A and the Cu—S distance is 2.366 (3) A. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H⋯O hydrogen bonds linking the imidazolidine N—H hydrogen-bond donors to perchlorate O-atom acceptors.
TL;DR: The two-layer structure of Tb2Ni2Mg3 is a new representative of a homologous linear structure series of general formula R′k+nX2nR′′′2m+k based on structural fragments of the α-Fe, CsCl and AlB2 structure types.
Abstract: Single crystals of diterbium dinickel trimagnesium, Tb2Ni2Mg3, were synthesized from the elements by induction melting. The novel compound crystallizes in the space group Cmmm with one Mg atom of site symmetry mmm and the Tb, Ni and other Mg atom in m2m positions. This ternary compound represents a new structure type that is derived from Ru3Al2B2 by way of Wyckoff site distribution. The two-layer structure of Tb2Ni2Mg3 is a new representative of a homologous linear structure series of general formula R′k+nX2nR′′2m+k based on structural fragments of the α-Fe, CsCl and AlB2 structure types. The Tb atoms in the structure are enclosed in 17-vertex polyhedra, while rhombododecahedra and distorted rhombododecahedra surround the Mg atoms, and equatorially tricapped trigonal prisms form around the Ni atoms. All interatomic distances indicate metallic type bonding.