Flunarizinium hydrogen maleate.

In the cation of the title salt {systematic name: 4-[bis-(4-fluoro-phen-yl)meth-yl]-1-[(2E)-3-phenyl-prop-2-en-1-yl]piperazin-1-ium hydrogen maleate}, C26H27F2N2 (+)·C4H3O4 (-), the protonated piperazine ring is in a chair conformation. The dihedral angle between the 4-fluoro-phenyl rings is 68.2 (2)°. An intra-molecular O-H⋯O hydrogen bond occurs in the anion. In the crystal, N-H⋯O, C-H⋯O and C-H⋯F inter-actions are observed, which link the ions into [001] chains.

1-[Bis(4-fluoro-phen-yl)meth-yl]piperazine.

In the title mol-ecule, C(17)H(18)F(2)N(2), the dihedral angle between the benzene rings is 73.40 (3)°. The piperazine ring is close to an ideal chair conformation and the N-H hydrogen is in an equatorial position. In the crystal, molecules are linked via weak C-H⋯F hydrogen bonds.

Methyl 2,2-diphenyl-2-(prop-2-yn-1-yl-oxy)acetate.

The mol-ecular structure of the title compound, C(18)H(16)O(3), exhibits a new R(2)-C(COOMe)(OCH(2)CCH) group. The C-O-C-C torsion angle is 153.3 (1)°. The dihedral angles are 79.89 (5)° between phen-yl/phenyl planes, and 73.13 (5) and 79.05 (8)° for the two COOMe/phenyl plane pairs.

(E)-5-(2-Chloro-phen-yl)-7-ethyl-2-oxo-2,3-dihydro-1H-thieno[2,3-e][1,4]diazepin-4-ium 2,4,6-trinitro-phenolate.

In the title molecular salt, C(15)H(14)ClN(2)OS(+)·C(6)H(2)N(3)O(7) (-), protonation occurred on the double-bonded N atom. One of the nitro groups shows slight disorder over two orientations, with an occupancy ratio of 0.91:0.09. In the crystal, classical N-H⋯O hydrogen bonds, as well as C-H⋯O contacts connect the components into a three-dimensional network. The seven-membered ring adopts a boat-like conformation. The least-squares plane defined by its non-H atoms encloses an angle of 38.99 (6)° with the benzene ring bonded to it.

Redetermination of loperamide monohydrate.

The structure of the title compound {systematic name: 4-[4-(4-chloro-phen-yl)-4-hy-droxy-piperidin-1-yl]-N,N-dimethyl-2,2-di-phenyl-butanamide monohydrate}, C(29)H(33)ClN(2)O(2)·H(2)O, has been redetermined at 170 (2) K. The redetermination is of significantly higher precision than the previous structure determination at room temperature and includes the H-atom coordinates that were not included in the previous report [Germain et al. (1977 ▶). Acta Cryst. B33, 942-944]. It consists of a piperidin-1-yl ring in a distorted chair conformation, with the N,N-dimethyl-α,α-diphenyl-butyramide and the 4-chloro-phenyl and hy-droxy groups bonded in para positions and an external water mol-ecule within the asymmetric unit. The dihedral angles between the mean plane of the piperidine ring and the 4-chloro-phenyl and two benzene rings are 83.4 (5), 76.4 (2) and 85.9 (2)°, respectively. The two benzene rings are inclined to one another by 50.8 (6)°. In the crystal, mol-ecules are linked by O-H⋯O and O-H⋯N hydrogen bonds and weak C-H⋯O intermolecular interactions, forming an infinite two-dimensional network along [110].

2-Amino-N-[3-(2-chloro-benzo-yl)-5-ethyl-thio-phen-2-yl]acetamide.

In the title compound, C(15)H(15)ClN(2)O(2)S, the 2-amino-acetamide N-C(=O)-C-N unit is approximately planar, with an r.m.s. deviation of 0.020 (4) Å. The central thio-phene ring makes dihedral angles of 7.84 (11) and 88.11 (11)°, respectively, with the 2-amino-acetamide unit and the 2-chloro-phenyl ring. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are linked by an N-H⋯O hydrogen bond and weak C-H⋯O inter-actions into a chain along the c axis. A C-H⋯π inter-action is also present.

3,3-Dimethyl-2-benzofuran-1(3H)-one.

In the title compound, C(10)H(10)O(2), all the non-H atoms except the methyl C atoms lie on a crystallographic mirror plane. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into zigzag chains running parallel to [100]. Weak π-π stacking inter-actions between the benzene rings [centroid-centroid distance = 3.9817 (5) Å] link the chains in the [010] direction.

2-(2-Benzyl-phen-yl)propan-2-ol.

There are two mol-ecules in the asymmetric unit of the title compound, C(16)H(18)O, a tertiary alcohol featuring a 2-benzyl-phenyl substituent. Co-operative O-H⋯O hydrogen bonds connect the mol-ecules into tetra-mers.

Desipramine hydro-chloride: a non-merohedrally twinned structure.

The title compound, C(18)H(23)N(2) (+)·Cl(-), is a non-merohedrally twinned salt [domains 0.9288 (3) and 0.0712 (3)] which crystallizes with four independent cation-anion pairs in the asymmetric unit. The seven-membered ring in each of the cations adopts a boat conformation, thus creating a butterfly effect within the ring system. The average value of the dihedral angle between the two aromatic rings in the four cations is 57.1 (1)°. The crystal packing is stabilized only slightly by a collection of inter-mediate N-H⋯Cl hydrogen-bonding inter-actions, which produce a weak, but cooperative, infinite, one-dimensional, inter-molecular hydrogen-bond network along the a axis. A MOPAC PM3 computational calculation gives support to these observations.

Etoricoxibium picrate.

IN THE CATION OF THE TITLE SALT (SYSTEMATIC NAME: 5-{5-chloro-3-[4-(methyl-sulfon-yl)phen-yl]-2-pyrid-yl}-2-methyl-pyridinium 2,4,6-trinitro-phenolate), C(18)H(16)ClN(2)O(2)S(+)·C(6)H(2)N(3)O(7) (-), the mean planes of the two pyridine rings in the bipyridine unit are twisted by 33.9 (2)° with respect to each other. The dihedral angles between the mean planes of the sulfonyl-benzene ring and the chloro-pyridine and methyl-pyridine rings are 51.2 (0) and 49.3 (9)°, respectively. The picrate anion inter-acts with the protonated N atom through a bifurcated N-H⋯(O,O) hydrogen bond, forming an R(1) (2)(6) ring motif with the N atom from the methyl-pyridine group of an adjacent cation. N-H⋯O hydrogen bonds, weak C-H⋯O and π-π stacking inter-actions [centroid-centroid distances = 3.8192 (9)and 3.6749 (9)] occur in the crystal packing, creating a two-dimensional network structure along [110].

Levocetirizinium dipicrate.

There are two cation-dianion pairs in the asymmetric unit of the title compound, C(21)H(27)ClN(2)O(3) (2+)·2C(6)H(2)N(3)O(7) (-) {systematic name: 1-[2-(carb-oxy-meth-oxy)eth-yl]-4-[(R)-(4-chloro-phen-yl)phenyl-meth-yl]piperazine-1,4-diium bis-(2,4,6-trinitro-phenol-ate)}. The piperazine group in the levocetirizinium cation is protonated at both N atoms. The acetyl end groups form R(2) (2)(8) hydrogen-bonded motifs with adjacent cations. Each picrate anion inter-acts with the proponated N atom in the cation through a bifurcated N-H⋯O hydrogen bond, forming R(1) (2)(6) ring motifs. Strong and weak inter-molecular N-H⋯O and strong O-H⋯O hydrogen bonds, and weak π-ring and π-π stacking inter-actions [centroid-centroid distance = 3.7419 (14) Å] dominate the crystal packing, creating a three-dimensional supra-molecular structure.

1-[2-(2-Bromo-phen-yl)eth-yl]-4-chloro-2-nitro-benzene.

In the title mol-ecule, C(14)H(11)BrClNO(2), the dihedral angle between the mean planes of the bromo-substitued benzene and the chloro-substituted benzene rings is 1.8 (4) °. The nitro group is twisted by 15.8 (6)° from the mean plane of the benzene ring to which it is attached. The crystal packing is influenced by weak inter-molecular C-H⋯O inter-actions and weak π-π stacking inter-actions [centroid-centroid distances = 3.903 (2), 3.596 (2) and 3.903 (2) Å].

1-(2-Methyl-5-nitro-phenyl)guanidinium picrate.

In the crystal structure of the title salt, C(8)H(11)N(4)O(2) (+)·C(6)H(2)N(3)O(7) (-), the pictrate anion participates in extensive hydrogen bonding with the guanidinium ion group of the cation, linking the mol-ecules through N(+)-H⋯O(-) hydrogen bonds and inter-molecular N-H⋯O and C-H⋯O inter-actions. These hydrogen-bonding configurations involve two three-centre/bifurcated bonds [N-H⋯(O,O)] that are observed between two N atoms from the guanidinium ion group of the cation and the o-NO(2) and phenolate O atoms of the picrate anion. In addition, π-π inter-actions also contribute to the crystal packing, with a centroid-to-centroid distance of 3.693 (6) Šand a slippage angle of 1.614°. A significant number of conformational differences are observed between the salt in the crystal structure and the models obtained by density functional theory (DFT) calculations of the geometry-optimized structure.

11-[3-(Dimethyl-amino)prop-yl]-6,11-dihydro-dibenzo[b,e]thiepin-11-ol.

There are two independent mol-ecules (A and B) in the asymmetric unit of the title compound, C(19)H(23)NOS. In each mol-ecule, the seven-membered thiepine ring is bent into a slightly twisted V-shape. The dihedral angles between the mean planes of the two benzene rings fused to the thiepine ring are 75.7 (5) in mol-ecule A and 73.8 (4)° in mol-ecule B. In both mol-ecules, an intra-molecular O-H⋯N hydrogen bond occurs. In the crystal, weak inter-molecular C-H⋯O and C-H⋯π-ring inter-actions are observed.

4-(4-Carboxy-benz-yl)-1-methyl-piperazin-1-ium picrate.

The title compound, C(13)H(19)N(2)O(2) (+)·C(6)H(2)N(3)O(7) (-), is a salt obtained by cocrystallization of 4-[(4-methyl-piperazin-1-yl)meth-yl]benzoic acid and picric acid. The cations adopt an 'L-shaped' conformation and are linked into chains along [010] by O-H⋯N hydrogen bonds. The NH group of each piperazinium ring forms a hydrogen bond to the phenolate O atom of a picrate anion, and the picrate anions form face-to-face contacts with an inter-planar separation of 3.023 (1) Å.

2-Amino-5-nitro-phenyl 2-chloro-phenyl ketone.

In the title compound, C(13)H(9)ClN(2)O(3), an intra-molecular hydrogen bond between the carbonyl O and an amine H atom from the 2-amino-benzoyl group stabilizes the mol-ecule, keeping these two groups nearly in the same plane [dihedral angle 14.6 (6)°]. The dihedral angle between the mean planes of the planar 2-amino-benzoyl and 2-chloro-benzoyl groups is 73.8 (6)°. The crystal packing is stabilized by a collection of inter-mediate hydrogen-bonding inter-actions which forms an infinite N-H⋯O⋯H-N-H⋯O hydrogen-bonded chain along the c axis in concert with weak N-H⋯Cl inter-actions in the same direction, producing a two-dimensional inter-molecular bonding network parallel to (001). Additional weak C-Cl⋯Cg [Cl⋯Cg = 3.858 (3) Å] and N-O⋯Cg [O⋯Cg = 3.574 (1) and 3.868 (6) Å] π-ring inter-actions provide added support to the crystal stability. A MOPAC computational calculation gives support to these observations.

Protonation of trimipramine salts of maleate, mesylate and hydrochloride observed by 1H, 13C and 15N NMR spectroscopy.

Protonation of the tricyclic antidepressant drug trimipramine with maleic acid, methanesulfonic acid and hydrochloric acid was studied using 1H, 13C and 15N NMR spectroscopy at natural abundance. The effect of counter ions on the protonation was compared under identical conditions of solvent, concentration and temperature using homonuclear and heteronuclear one- and two-dimensional experiments. Differential protonation of the terminal tertiary amine nitrogen is determined from the indirect spin-spin couplings, chemical shifts, 13C relaxation data and variable-temperature experiments. In the maleate salt, only one of the acidic protons is involved in protonation, the other being associated with the anion moiety. 15N chemical shifts of the protonated nitrogens are nearly linearly related to the pK(a) of the constituent acid.

Differential protonation and dynamic structure of doxylamine succinate in solution using 1H and 13C NMR.

A protonation and dynamic structural study of doxylamine succinate, a 1:1 salt of succinic acid with dimethyl-[2-(1-phenyl-1-pyridin-2-yl-ethoxy)ethyl]amine, in solution using one- and two-dimensional 1H and 13C NMR experiments at variable temperature and concentration is presented. The two acidic protons of the salt doxylamine succinate are in 'intermediate' exchange at room temperature, as evidenced by the appearance of a broad signal. This signal evolves into two distinct signals below about -30 degrees C. A two-dimensional 1H-1H double quantum filtered correlation experiment carried out at -55 degrees C shows protonation of one of the acidic protons to the dimethylamine nitrogen. A two-dimensional rotating frame 1H-1H NOE experiment at the same temperature reveals that the other proton remains with the succinate moiety. Comparison of the 1H and 13C chemical shifts and the 13C T1 relaxation times of the salt with those of the free base further substantiate the findings.

Solvent-free synthesis of benzo[a]pyrene 7,8-diol 9,10-epoxide adducts at the N(2)-position of deoxyguanosine.

[reaction: see text] The first solid-state (or solvent-free) synthesis of protected deoxyguanosine (dG) adducts of benzo[a]pyrene diol epoxides at room temperature is reported. Whereas dG adducts derived from cis- and trans-opening of (+/-)-7beta,8alpha-dihydroxy-9beta,10beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (DE-1 1) are formed as a 1:1 mixture, the direct opening of the diastereomeric (+/-)-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (DE-2, 2) produced a 15:85 ratio favoring the trans-opened dG adduct 7.