Three Concomitant Crystal Forms of Monomeric Cobalt Chloride with 3-Pyridinemethanol.

Three new crystal forms of a mononuclear cobalt(II) chloride with 3-pyridinemethanol (3PM), CoCl2(3PM)4, have been prepared: triclinic (P1̄) and monoclinic (P21/c) polymorphs and its dihydrate which crystallises in the triclinic P1̄ space group. The three crystal forms differ by the orientation of 3PM ligands in the mononuclear entities and consequently in their packing arrangements. All three forms crystallise concomitantly. Their crystal structures have been determined at 150K.

Fluconazole-malonic acid (1/1).

Co-crystallizaton of the anti-fungal drug fluconazole [2-(2,4-difluoro-phen-yl)-1,3-bis-(1H-1,2,4-triazol-1-yl)propan-2-ol] with malonic acid in acetonitrile solution resulted in the formation of the title 1:1 co-crystal, C13H12F2N6O·C3H4O4. The geometry around the central fluconazole atom is distorted tetrahedral. The dihedral angles between the triazole rings and the fluorinated phenyl ring are 30.64 (7) and 61.91 (5)°. In the crystal, the basic packing motif may be envisioned as a cyclic aggregate formed of two fluconazole mol-ecules linked by two malonic acid mol-ecules through O-H⋯N and O-H⋯O hydrogen bonds. Such aggregates are further connected into (001) layers by further O-H⋯N hydrogen bonds. The structure also features weak non-classical C-H⋯O and C-H⋯N inter-actions.

Bis(acetato-κO)bis-[2-(pyridin-2-yl)ethanol-κ(2)N,O]copper(II).

The title compound, [Cu(CH(3)COO)(2)(C(7)H(9)NO)(2)], is a monomeric complex with an octa-hedral geometry. The Cu(II) atom is located on an inversion center and is coordinated by acetate and 2-(pyridin-2-yl)ethanol ligands. The acetate group is coordinated in a monodentate manner, while the 2-(pyridin-2-yl)ethanol is coordinated as a bidentate ligand involving the endocyclic N atom and the hy-droxy O atom of the ligand side chain. An intra-molecular hydrogen bond is observed between the hy-droxy O atom and the non-coordinated acetate O atom. No classical inter-molecular hydrogen-bond contacts were observed. However, the crystal packing is effected by C-H⋯O inter-actions, which link the mononuclear entities into layers parallel to the bc plane.

Two concomitant polymorphs of monomeric nickel acetate with 2-pyridineethanol.

A new mononuclear nickel(II) acetate with 2-pyridineethanol, Ni(ac)2(2-PyEtOH)2 has been prepared. The reaction product is a mixture of two polymorphic forms that crystallize concomitantly: triclinic (PI) and monoclinic (P21/c). Their structures have been determined at 150 K. The molecular structure of the mononuclear complex shows similar geometry in both polymorphic structures but they differ notably in the arrangement of mononuclear entities in space. The crystal densities are significantly different, nevertheless they behave as concomitant polymorphs.

A 1:1 cocrystal of fluconazole with salicylic acid.

The interaction of the antifungal pharmaceutical agent fluconazole with salicylic acid in acetonitrile solution yields the 1:1 cocrystal 2-(2,4-difluorophenyl)-1,3-bis(1H-1,2,4-triazol-1-yl)propan-2-ol-2-hydroxybenzoic acid (1/1), C(13)H(12)F(2)N(6)O·C(7)H(6)O(3). The asymmetric unit consists of one molecule of fluconazole and one molecule of salicylic acid, both in their neutral forms. Both crystal agents form head-to-tail hydrogen-bonded dimers, which are further connected into hydrogen-bonded extended zigzag tapes propagating along the ac diagonal.

Formation and structure elucidation of two novel spiro[2H-indol]-3(1H)-ones.

The molecular structures of two byproducts 1,1''-diphenyl-3',4'-dihydrodispiro[indole-2,2'-furan-5',2''-indole]-3,3''(1H, 1''H)-dione (3) and 1,5'-diphenyl-4',5'-dihydro-3'H-spiro[indole-2,2'-pyrano[3,2-b]indol]-3(1H)-one (4), which accompanied the rearrangement of 3-hydroxy-3-methyl-1-phenylquinoline-2,4(1H,3H)-dione (1) to 2-hydroxy-2-methyl-1-phenyl-1,2-dihydro-3H-indol-3-one (2), have been elucidated by NMR, MS, and X-ray diffraction.

Structures of artificial sweeteners--cyclamic acid and sodium cyclamate with other cyclamates.

In the course of a study on artificial sweeteners, new crystal structures of cyclamic acid, sodium cyclamate, potassium cyclamate, ammonium cyclamate, rubidium cyclamate and tetra-n-propylammonium cyclamate have been determined. Cyclamic acid exists in its zwitterionic form in the crystalline state. The zwitterions are connected through hydrogen bonds of the N-H...O type to form two-dimensional sheets. The sodium, potassium, ammonium and rubidium cyclamates are isostructural, with the cyclamate moieties linked through hydrogen bonds into linear chains. Taking into account the connectivity through cations, two-dimensional layers with a hydrophobic surface are constructed. In tetra(n-propyl)ammonium cyclamate the large, non-coordinating cation apparently prevents the formation of chains and thereby facilitates the centrosymmetric head-to-head discrete dimeric arrangement of the cyclamate moieties.

A new copper(II) basic sulfate: poly[3-aminopyridinium mu3-hydroxido-di-mu3-sulfato-bis[aquacopper(II)]].

The crystal structure of the title basic copper(II) sulfate, {(C(5)H(7)N(2))[Cu2(OH)(SO4)2(H2O)2]}n, shows an unprecedented structural arrangement of two distinct copper centres. CuO6 and CuO5 polyhedra are linked through bridging hydroxide and sulfate anions to form negatively charged infinite chains propagated along the a axis. The negative charge is balanced by 3-aminopyridinium cations that are held in the structure by extensive hydrogen bonding to the inorganic chains. Additionally, the cationic arrangement features pi-pi stacking.

A dimeric cobalt(II)-suberate complex with 3-aminopyridine.

The title complex, mu-octane-1,8-dioato-bis[bis(3-aminopyridine)chloro(methanol)cobalt(II)], [Co2(C8H12O4)Cl2(C5H6N2)4(CH4O)2], is located on a crystallographic centre of inversion. The coordination around each of the Co centres is distorted octahedral, involving two N, three O and one Cl atom. Discrete dimers are connected in a three-dimensional arrangement through N-H...O, N-H...Cl and O-H...O hydrogen-bond interactions.

Conformational flexibility in a triazole nucleoside derivative: 4-cyano-5-cyanomethyl-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)-1,2,3-triazole.

The crystal-structure determination of the molecular structure of the hydrophobic compound, 4-cyano-5-cyanomethyl-1-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)-1,2,3-triazole, C16H17N5O7, provides us with two different conformations of ribofuranosyl moieties [(C2'-exo, C3'-endo) and C2'-exo] with two markedly different N-glycosidic angles. There are two molecules in the asymmetric unit of the crystal and the overall stereochemistry of the molecules are influenced predominantly by weak intramolecular bifurcated and trifurcated hydrogen bonds of the type C-H...O and C-H...N, where endo-H atoms attached to C2' and C3' are involved. The molecules in the crystal are interconnected with longer intermolecular bonds of the same type. There are empty channels (occupying 14.0% of the whole volume of the unit cell), which are extended along b-axis of the entire crystal.

A novel copper(II) complex with 1,10-phenanthroline and ciprofloxacin.

The X-ray structure analysis of the title compound, chloro[1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazin-4-ium-1-yl)-3-quinolinecarboxylate-kappa(2)O(3),O(4)](1,10-phenanthroline-kappa(2)N,N')copper chloride dihydrate, [CuCl(C(17)H(18)FN(3)O(3))(C(12)H(8)N(2))]Cl x 2H(2)O or [CuCl(cfH)(phen)]Cl x 2H(2)O, where cfH is 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(piperazin-4-ium-1-yl)-3-quinolinecarboxylate and phen is 1,10-phenanthroline, shows that the geometry around the Cu ion is a slightly distorted square pyramid. Two O atoms of the carbonyl and carboxyl groups of ciprofloxacin and two N atoms of 1,10-phenanthroline are coordinated to the metal centre in the equatorial plane, and a Cl(-) ion is coordinated at the apical position. Extensive intermolecular hydrogen bonding produces a supramolecular structure that consists of alternating six- and 12-membered rings.

2-aminothiazole and 2-aminothiazolinone derivatives.

The reaction of different substituted alpha-cyanooxiranes with thiourea resulted in the formation of the 2-aminothiazolinone derivative 2-amino-5-(2,5-dimethoxyphenyl)-1,3-thiazol-4(5H)-one, C(11)H(12)N(2)O(3)S, (I), and the 2-aminothiazole derivative ethyl 2-amino-5-(2,5-dimethoxyphenyl)-1,3-thiazole-4-carboxylate, C(14)H(16)N(2)O(4)S, (II). The geometries of the two crystallographically independent molecules in (II) are nearly identical but mirror related. The crystal structures of both compounds contain two types of intermolecular hydrogen bonds.

4-aminopyridinium hydrogen maleate.

The title compound, C(5)H(7)N(2)(+)...C(4)H(3)O(4)(-), crystallizes in space group P2(1) with one ion pair in the asymmetric unit. The hydrogen maleate anion possesses nearly planar geometry and displays an extremely short intramolecular O--H...O hydrogen bond, with an O...O distance of 2.4198 (19) A. Classical N-H...O hydrogen bonds, together with short C--H...O contacts, generate an extensive hydrogen-bonding network.

D-Gulonolactone as a synthon for L-noviose: first preparation of 4-O-demethyl-L-noviofuranose and related derivatives.

[reaction: see text] A new synthesis of L-noviose (11), a sugar moiety of novobiocin, is presented. D-Gulonolactone was initially converted in a few steps to the key ester derivative 7 [1-O-benzyl methyl 2,3-O-(1-methylethylidene)-alpha-L-lyxofuranosiduronate]. An appropriate selection of protecting groups enabled transformation of 7 under mild reaction conditions to 4-O-demethyl-L-noviofuranose 9a and related 9b-c. Derivatives 9 were further converted either to L-lyxopyranoses (10a and 10b) or to methyl L-lyxofuranoside 12.

Cone and 1,3-alternate conformers of 1,3-bis(ethoxycarbonylmethoxy)-2,4-dihydroxycalix[4]arene and 1,2,3,4-tetrakis(ethoxycarbonylmethoxy)calix[4]arene.

The two title ethoxycarbonylmethoxy derivatives of calix[4]arene, namely diethyl 2,4-dihydroxycalix[4]arene-1,3-diyldi(oxyacetate), C(36)H(36)O(8), (I), and tetraethyl calix[4]arene-1,2,3,4-tetrayltetra(oxyacetate), C(44)H(48)O(12), (II), form two different conformations, viz. a cone in (I), where intramolecular hydrogen bonds are formed through OH groups in a partially substituted calix[4]arene, and a 1,3-alternate form of a completely substituted calix[4]arene in (II). A unique three-dimensional array of molecules exists in (II), with the channels extended along the entire crystal.

Precursor of a beta-lactamase inhibitor: allyl (4S,8S,9R)-10-[(E)-ethylidene]-4-methoxy-11-oxo-1-azatricyclo[7.2.0.0(3,8)]undec-2-ene-2-carboxylate.

The molecular structure of the title tricyclic compound, C(17)H(21)NO(4), which is the immediate precursor of a potent synthetic inhibitor [Lek157: sodium (8S,9R)-10-[(E)-ethylidene]-4-methoxy-11-oxo-1-azatricyclo[7.2.0.0(3,8)]undec-2-ene-2-carboxylate] with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclohexyl ring and the carbonyl group of the beta-lactam ring, which takes part in the formation of the initial tetrahedral acyl-enzyme complex. In this hydrophobic molecule, the overall geometry is influenced by C[bond]H...O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) A, with corresponding normalized H.O distances of 2.30 and 2.46 A], whereas the molecules are interconnected through intermolecular C[bond]H...O hydrogen bonds [3.335 (4)-3.575 (5) A].

3,4-Dihydro-6-methyl-3-beta-D-ribofuranosyl-4,5'-cyclo-9H-imidazo[1,2-a]purin-9-one hydrate.

In the title compound, C(13)H(13)N(5)O(4) x H(2)O (4,5'-cyclowyosine x H(2)O), the cyclization forces a syn arrangement of the aglycon with respect to the sugar moiety. The ribofuranose part of the molecule displays a beta-D configuration with an envelope C1'-endo pucker. The molecules are arranged in columns along the short a axis and are linked to water molecules through O-H...O and O-H...N hydrogen bonds.