ABSTRACT
The crystal structures of the monoclinic and triclinic polymorphs of zoledronic acid, C5H10N2O7P2, have been established from laboratory powder X-ray diffraction data. The molecules in both polymorphs are described as zwitterions, namely 1-(2-hydroxy-2-phosphonato-2-phosphonoethyl)-1H-imidazol-3-ium. Strong intermolecular hydrogen bonds (with donor-acceptor distances of 2.60â Å or less) link the molecules into layers, parallel to the (100) plane in the monoclinic polymorph and to the (1-10) plane in the triclinic polymorph. The phosphonic acid groups form the inner side of each layer, while the imidazolium groups lie to the outside of the layer, protruding in opposite directions. In both polymorphs, layers related by translation along [100] interact through weak hydrogen bonds (with donor-acceptor distances greater than 2.70â Å), forming three-dimensional layered structures. In the monoclinic polymorph, there are hydrogen-bonded centrosymmetric dimers linked by four strong O-H...O hydrogen bonds, which are not present in the triclinic polymorph.
ABSTRACT
Afobazole {systematic name: 2-[2-(morpholin-4-yl)ethylsulfanyl]-1H-benzimidazole} is a new anxiolytic drug and Actins, Auzins & Petkune [(2012). Eur. Patent EP10163962] described four polymorphic modifications. In the present study, the crystal structures of two monoclinic polymorphs, 5-ethoxy-2-[2-(morpholin-4-ium-4-yl)ethylsulfanyl]-1H-benzimidazol-3-ium dichloride, C15H23N3O2S(2+)·2Cl(-), (II) and (IV), have been established from laboratory powder diffraction data. The crystal packing and conformation of the dications in (II) and (IV) are different. In (II), there are channels in the [001] direction, which offer atmospheric water molecules an easy way of penetrating into the crystal structure, thus explaining the higher hygroscopicity of (II) compared with (IV).
Subject(s)
Benzimidazoles/chemistry , Morpholines/chemistry , Crystallization , Models, Molecular , Powder Diffraction , X-Ray DiffractionABSTRACT
In the cation of the title compound, C(24)H(27)N(2)O(4) (+)·H(2)PO(4) (-)·C(3)H(8)O [systematic name: 3-(9H-carbazol-4-yl-oxy)-2-hydr-oxy-N-[2-(2-methoxy-phen-oxy)eth-yl]propan-1-aminium dihydro-gen phosphate propan-2-ol solvate], the mean planes of the tricyclic carbazole system and the benzene ring form a dihedral angle of 42.00â (16)°. In the crystal structure, classical inter-molecular O-Hâ¯O and N-Hâ¯O hydrogen bonds link the cations, anions and solvent mol-ecules into layers parallel to the ac plane.
ABSTRACT
The asymmetric unit of the title compound, C(16)H(17)ClNO(2)S(+)·HSO(4) (-), (I) [systematic name: (+)-(S)-5-[(2-chloro-phen-yl)(meth-oxy-carbon-yl)meth-yl]-4,5,6,7-tetra-hydro-thieno[3,2-c]pyridin-5-ium hydrogen sulfate], contains two independent cations of clopidogrel and two independent hydrogensulfate anions. The two independent cations are of similar conformation; however, this differs from that observed in ortho-rhom-bic form (II) [Bousquet et al. (2003 â¶). US Patent No. 6 504 030]. The H-N-C(chiral)-H fragment shows a trans conformation in both independent cations in (I) and a gauche conformation in (II). In (I), classical inter-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds link two independent cations and two independent anions into an isolated cluster, in which two cations inter-act with one anion only via N-Hâ¯O hydrogen bonds. Weak inter-molecular C-Hâ¯O hydrogen bonds further consolidate the crystal packing.
ABSTRACT
Eleven complexes of a hybrid ligand 4'-(4'''-benzo-15-crown-5)-methyloxy-2,2':6',2''-terpyridine (L) were synthesized and characterised by elemental analysis, IR-spectroscopy and X-ray analysis. The crystal structures of seven complexes were determined either from single-crystal data ([NaNCS.L] (6)and [CuL2.NaNCS.Na(NCS)2]+.NCS-.CH3CN) (11) or from powder diffraction data ([CoL2]2+.2NCS- (5) and [ML2]2+.2PF6-.nEtOH.mH2O, M = Ni(II) (1), Co(II) (2), Cu(II) (3), Zn(II) (4)) and revealed good coordinating properties of the ligand L and structural diversity of the obtained compounds. In compounds 1-5, the pi-pi interactions between pyridine rings or between pyridine and benzene rings play an important role in association of the cations.
Subject(s)
Cobalt/chemistry , Copper/chemistry , Crown Ethers/chemistry , Nickel/chemistry , Organometallic Compounds , Pyridines/chemistry , Sodium/chemistry , Zinc/chemistry , Computer Simulation , Crystallography, X-Ray , Ligands , Models, Chemical , Models, Molecular , Molecular Structure , Organometallic Compounds/chemical synthesis , Organometallic Compounds/chemistryABSTRACT
The asymmetric unit of the title compound, [Cd(C(30)H(31)N(3)O(6))(2)](PF(6))(2)·3H(2)O, contains one half-cation with the Cd(II) center situated on a twofold rotational axis, one hexa-fluoridophosphate anion and two uncoordinated water mol-ecules, one of which is also situated on a twofold rotational axis. The cations are associated into columns along the a axis through π-π inter-actions between the pyridine and benzene rings, with a centroid-centroid distance of 3.72â (5)â Å. Inter-molecular O-Hâ¯O, C-Hâ¯O and C-Hâ¯F hydrogen bonds consolidate the crystal packing.
ABSTRACT
IN THE CATION OF THE TITLE COMPOUND [SYSTEMATIC NAME: 3-(9H-carbazol-4-yl-oxy)-2-hydr-oxy-N-[2-(2-methoxy-phen-oxy)eth-yl]propan-1-aminium dihydrogen phosphate hemihydrate], C(24)H(27)N(2)O(4) (+)·H(2)PO(4) (-)·0.5H(2)O, the mean planes of the tricyclic ring system and the benzene ring form a dihedral angle of 87.2â (2)°. In the crystal structure, the solvent water mol-ecule is situated on a twofold rotation axis linking two cations via O-Hâ¯O and N-Hâ¯O hydrogen bonds. The anions contribute to the formation O-Hâ¯O and N-Hâ¯O hydrogen bonds between the anions and cations, which consolidate the crystal packing.
ABSTRACT
The central pyridine ring of the 2,2':6',2''-terpyridine fragment of the title compound, C(29)H(29)N(3)O(6), forms dihedral angles of 5.2â (5), 10.1â (5) and 86.0â (6)°, respectively, with the two outer pyridine rings and the benzene ring of the benzo-15-crown-5 fragment.