Independent Organic Mol-ecules Research Articles

Co-crystallization of a neutral mol-ecule and its zwitterionic tautomer: structure and Hirshfeld surface analysis of 5-methyl-4-(5-methyl-1H-pyrazol-3-yl)-2-phenyl-2,3-di-hydro-1H-pyrazol-3-one 5-methyl-4-(5-methyl-1H-pyrazol-2-ium-3-yl)-3-oxo-2-phenyl-2,3-di-hydro-1H-pyrazol-1-ide monohydrate.

The title compound, 2C14H14N4O·H2O, comprises a neutral mol-ecule containing a central pyrazol-3-one ring flanked by an N-bound phenyl group and a C-bound 5-methyl-1H-pyrazol-3-yl group (at positions adjacent to the carbonyl substituent), its zwitterionic tautomer, whereby the N-bound proton of the central ring is now resident on the pendant ring, and a water mol-ecule of crystallization. Besides systematic variations in geometric parameters, the two independent organic mol-ecules have broadly similar conformations, as seen in the dihedral angle between the five-membered rings [9.72 (9)° for the neutral mol-ecule and 3.32 (9)° for the zwitterionic tautomer] and in the dihedral angles between the central and pendant five-membered rings [28.19 (8) and 20.96 (8)° (neutral mol-ecule); 11.33 (9) and 11.81 (9)°]. In the crystal, pyrazolyl-N-H⋯O(carbon-yl) and pyrazolium-N-H⋯N(pyrazol-yl) hydrogen bonds between the independent organic mol-ecules give rise to non-symmetric nine-membered {⋯HNNH⋯NC3O} and {⋯HNN⋯HNC3O} synthons, which differ in the positions of the N-bound H atoms. These aggregates are connected into a supra-molecular layer in the bc plane by water-O-H⋯N(pyrazolide), water-O-H⋯O(carbon-yl) and pyrazolyl-N-H⋯O(water) hydrogen bonding. The layers are linked into a three-dimensional architecture by methyl-C-H⋯π(phen-yl) inter-actions. The different inter-actions, in particular the weaker contacts, formed by the organic mol-ecules are clearly evident in the calculated Hirshfeld surfaces, and the calculated electrostatic potentials differentiate the tautomers.

Crystal structure and Hirshfeld surface analysis of N-{2-[(E)-(4-methyl-benzyl-idene)amino]-phen-yl}-2-(5-methyl-1-H-pyrazol-3-yl)acetamide hemihydrate.

The asymmetric unit of the title compound, C20H20N4O·0.5H2O, contains two independent organic mol-ecules (1 and 2) and a water mol-ecule of crystallization. The two mol-ecules differ primarily in the dihedral angles between the aromatic rings, which are 7.79 (7) and 29.89 (7)° in mol-ecules 1 and 2, respectively. In each mol-ecule there is intra-molecular C-H⋯O hydrogen bond forming an S(6) ring motif. In mol-ecule 1 there is an intra-molecular N-H⋯π(pyrazole) inter-action and an intra-molecular C-H⋯π(pyrazole) inter-action present. Mol-ecule 1 is linked to mol-ecule 2 by a C-H⋯π(benzene ring) inter-action. An intra-molecular N-H⋯N hydrogen bond and an intra-molecular C-H⋯N hydrogen bond are also present in mol-ecule 2. In the crystal, the three components are linked by Owater-H⋯N, N-H⋯Owater and N-H⋯N hydrogen bonds, forming chains along the [100] direction. The chains are linked by C-H⋯O and C-H⋯N hydrogen bonds, forming layers parallel to the ab plane. Finally, the layers are linked by C-H⋯π inter-actions, forming a three-dimensional structure.

4-Methoxy-N-(1-methyl-1H-indazol-7-yl)benzenesulfonamide hemihydrate

The asymmetric unit of the title compound, 2C15H15N3O3S·H2O, comprises two crystallographically independent organic molecules and one water molecule, all in general positions. Each organic molecule comprises an indazolyl system linked through a sulfonamide group to a methoxybenzene ring. The most important difference between the two organic molecules is the dihedral angle between the fused-ring system and the methoxybenzene ring, which is 56.32 (7)° in one molecule and 35.35 (8)° in the other. In the crystal, the organic and water molecules are connected into supramolecular chains along thecaxis through O—H...N, O—H...O, N—H...O and N—-H...N hydrogen bonds; in addition, a π–π interaction between pyrazolyl rings [inter-centroid separation = 3.7547 (12) Å] is noted.

Crystal structure of 2,2,4-trimethyl-2,3,4,5-tetra-hydro-1H-benzo[b][1,4]diazepine hemihydrate.

The title compound, C12H18N2·0.5H2O, crystallizes with two independent organic mol­ecules (A and B) in the asymmetric unit, together with a water mol­ecule of crystallization. The diazepine rings in each mol­ecule have a chair conformation. The dihedral angle between benzene ring and the mean plane of the diazepine ring is 21.15 (12)° in mol­ecule A and 17.42 (11)° in mol­ecule B. In the crystal, mol­ecules are linked by N—H⋯O and O—H⋯N hydrogen bonds, forming zigzag chains propagating along [001].

Crystal structure of N-[(2S,5R)-4-oxo-2,3-diphenyl-1,3-thia-zinan-5-yl]acetamide 0.375-hydrate.

The asymmetric unit of the title compound, C18H18N2O2S.0.375H2O, has two independent organic mol-ecules (A and B) and 3/4 of a water mol-ecule distributed over three sites. In mol-ecule A, the 1,3-thia-zine ring is in a boat conformation, with the C atoms at the 2- and 5-positions out of the plane. The angle between the two phenyl rings is 51.70 (12)°. In mol-ecule B, the thia-zine ring is in a half-chair conformation, with the S atom forming the back of the half-chair. The angle between the two phenyl rings is 84.44 (14)°. The A mol-ecule features an intra-molecular N-H⋯O hydrogen bond, which closes an S(5) ring motif. In the crystal, the corresponding N-H grouping of the B mol-ecule participates in an inter-molecular hydrogen bond to the A mol-ecule. The A mol-ecule participates in a C-H⋯O inter-action back to the B mol-ecule, whilst the B mol-ecule features an intra-molecular C-H⋯O link, which generates an S(10) loop.

Crystal structure of S,N-dibenzyl-d-penicillamine monohydrate.

In the asymmetric unit of the title compound, C19H23NO2S·H2O, there are two independent organic mol­ecules and two water mol­ecules. Both organic mol­ecules exist as the zwitterionic form. The dihedral angles between the planes of the rings in the organic mol­ecules are 86.84 (10) and 88.77 (11)°. An intramolecular N—H⋯S hydrogen bond occurs. In the crystal, organic and water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, generating a tape structure running along the b-axis direction.

ChemInform Abstract: In situ Assembled Boronate Ester Assisted Chiral Carboxylic Acid Catalyzed Asymmetric trans‐Aziridinations.

We developed herein a new chiral Bronsted acid catalyst which is composed of two independent organic molecules, a chiral diol, and 2-boronobenzoic acid. In situ formation of a boronate ester was utilized as a key process to generate an active catalyst. This boronate ester assisted chiral carboxylic acid catalyst was successfully applied to the trans-aziridination of N-Boc and N-benzyl imines with N-phenyldiazoacetamide. This is the first catalyst to achieve high enantioselectivities using N-benzyl imines.

In Situ Assembled Boronate Ester Assisted Chiral Carboxylic Acid Catalyzed Asymmetric Trans-Aziridinations

We developed herein a new chiral Brønsted acid catalyst which is composed of two independent organic molecules, a chiral diol, and 2-boronobenzoic acid. In situ formation of a boronate ester was utilized as a key process to generate an active catalyst. This boronate ester assisted chiral carboxylic acid catalyst was successfully applied to the trans-aziridination of N-Boc and N-benzyl imines with N-phenyldiazoacetamide. This is the first catalyst to achieve high enantioselectivities using N-benzyl imines.

EthylN-[4-(3-methyl-4,5-dihydrobenzo[g]indazol-1-yl)phenylsulfonyl]thiocarbamate ethanol monosolvate

The title compound, C21H20N3O3S2·CH3CH2OH, comprises two independent organic mol­ecules and two ethanol solvent mol­ecules. The mol­ecules are related by pseudo-mirror symmetry. In both mol­ecules, the N-bound benzene ring is twisted out of the plane of the pyrazole ring [the dihedral angles are 51.4 (3) and 44.1 (3)°, respectively]. Similarly, the benzene ring of the 1,2-dihydro­naphthalene residue is inclined with respect to the five-membered ring [dihedral angles 18.3 (3) and 22.2 (3)°]. Overall, each mol­ecule has a flattened U shape. Dimeric aggregates mediated by O—H⋯N(pyrazole) and amide-N—H⋯O hydrogen bonds feature in the crystal packing, whereby the ethanol mol­ecules link the independent organic mol­ecules, leading to four-mol­ecule aggregates.

(E)-MethylN′-[(1H-indol-3-yl)methylidene]hydrazinecarboxylate 0.25-hydrate

The asymmetric unit of the title compound, C11H11N3O2·0.25H2O, contains two independent organic mol­ecules and a water mol­ecule, which lies on a twofold rotation axis. The side chains of the two mol­ecules have slightly different orientations, the C=N—N—C torsion angle being −163.03 (15)° in one and −177.52 (14)° in the other, with each adopting a trans configuration with respect to the C=N bond. In the crystal, mol­ecules are linked into chains extending along b by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds and in addition, four inter­molecular C—H⋯π inter­actions are present.

4-(4-Chlorophenyl)-6-hydroxy-5-(2-thienylcarbonyl)-6-(trifluoromethyl)-3,4,5,6-tetrahydropyrimidin-2(1H)-one monohydrate

The asymmetric unit of the title compound, C16H12ClF3N2O3S·H2O, contains two crystallographically independent organic mol­ecules and two water mol­ecules. The organic species are linked by an inter­molecular O—H⋯O hydrogen bond, while the water mol­ecules are connected to them through inter­molecular O—H⋯N hydrogen bonds. The thio­phene and phenyl rings are oriented at dihedral angles of 62.35 (4) in the first independent mol­ecule and 60.74 (5)° in the second, while the pyrimidine rings adopt twisted conformations in both molecules. Intra­molecular N—H⋯F inter­actions result in the formation of two five-membered rings having envelope conformations. In the crystal structure, further inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into chains.

3,5-Dinitropyridin-4(1H)-one monohydrate

The three independent organic mol­ecules of 3,5-dinitro­pyridin-4(1H)-one monohydrate, C5H3N3O5·H2O, each feature an N—H⋯Owater hydrogen bond. Each water mol­ecule serves as hydrogen-bond donor to two carbonyl O atoms; these hydrogen bonds give rise to a layer motif. Two of the three formula units lie on special positions of site symmetry 2.

Ethyl [3-(2-pyridyl)pyrazol-1-yl]acetate monohydrate

The asymmetric unit of the title compound, C12H13N3O2·H2O, comprises two crystallographically independent organic molecules and two water molecules. There is an O—H...N hydrogen bond between each water molecule and the 2-substituted pyridyl ring of an organic molecule. The water molecules are further engaged in disordered O—H...O hydrogen bonds with each other, leading to the formation of a one-dimensional zigzag chain running parallel to the b axis.