Cesium-Fluoride-Promoted Synthesis of Stable Organocesium Reagents and Their Ambident Reactivities with Arynes.

Described are the diverse reactivities of novel, stable, ambident thio-organocesium reagents (bearing electron withdrawing groups) against benzynes. Reactions at reflux temperature predominantly led to the generation of various functionalized stable sulfonium ylides and at 40 °C the same reaction underwent direct c-arylation. Furthermore, lack of internal hydrogen on the cesium reagent helped to produce different ortho-bifunctional arynes in both the reactions. Interestingly, depending on the reactivities of substrates, the one-pot tri-component procedure generated either ylides or σ-bond insertion products.

Structural, Spectroscopic Investigation and Computational Study on Nitrate and Hydrogen Oxalate Salts of 2-Aminopyrimidine.

The proton transfer salts of 2-aminopyrimidine with nitric acid (2APNO) and oxalic acid (2APOX) were synthesized and crystallized successfully by solvent evaporation solution growth technique. The crystal packing is stabilized through intricate three dimensional hydrogen bonded network. Both, the molecular structures were optimized with Density Functional Theory (DFT) using B3LYP function and Hartree-Fock method with a 6-311++G(d,p) basis set. Optimized molecular parameters between the methods were compared for the cation showing appreciable agreement. The computed vibrational spectra are compared with experimental result which clearly demonstrates the strong N-H··· O vibrational behaviour. Thermal stability of the crystals were analyzed with TGA/DTA and the melting points of the salts, viz. 2APNO and 2APOX, were identified at 189.5 and 210.9 °C, respectively. The chemical hardness, electronegativity, chemical potential and electrophilicity index of the two crystals were determined by HOMO-LUMO plot. The lower band gap value obtained from the Frontier Molecular Orbital (FMO) analysis favours the possible pharmaceutical/biological activity of the salts.

Bis(4-sulfamoylanilinium) sulfate.

In the title salt, 2C6H9N2O2S(+)·SO4 (2-), the sulfate S atom is situated on a crystallographic twofold axis (the symmetry of the anion is 2). The anion exerts intense libration, which is manifested by shortening of the observed sulfate S-O bonds, as well as by features in the electron-density map. The crystal structure is stabilized through a three-dimensional hydrogen-bonding network formed by strong N-H⋯O hydrogen bonds.

4-Sulfamoylanilinium perchlorate.

In the crystal of the title salt, C6H9N2O2S(+)·ClO4 (-), the components are linked by N-H⋯O hydrogen bonds, forming a three-dimensional network. The cations are connected along a and b axes, leading to linear and zigzag C(3) and C(8) chain motifs, respectively. A cation-anion inter-action along the c axis leads to a C 2 (2)(12) chain motif. R 3 (3)(18) and R 3 (3)(20) ring motifs are observed as cation-anion-type inter-actions. These hydrogen-bonding ring and chain motifs are localized at z = 0 or 1, leading to alternate hydro-philic and hydro-phobic regions along the c axis as a result of the stacking of anions and the aromatic cationic parts.

Ethyl 3-(4-chloro-benzo-yl)-1-(4-chloro-benz-yl)-4-(4-chloro-phen-yl)-2,2-dioxo-3,4,6,7,8,8a-hexa-hydro-1H-pyrrolo-[2,1-c][1,4]thia-zine-1-carboxyl-ate.

In the title compound, C30H28Cl3NO5S, the pyrrolidine ring adopts an envelope conformation (with the N atom as the flap) and the thia-zine ring is in a distorted chair conformation. The mol-ecular structure shows three intra-molecular C-H⋯O inter-actions leading to self-associated ring S(6) and two S(7) motifs. In the crystal, the molecules are linked by C-H⋯O and C-H⋯Cl inter-actions. Two R 2 (2)(10) and one R 2 (2)(16) centrosymmetrically related ring motifs are observed in the unit cell and they are connected through C(6) and C(11) chain motifs extending along the b and c axes, respectively.

(E)-3-(4-Meth-oxy-phen-yl)-3-[3-(4-meth-oxy-phen-yl)-1H-pyrazol-1-yl]prop-2-enal.

In the title mol-ecule, C20H18N2O3, the pyrazole ring forms a dihedral angle of 2.2 (1)° with its meth-oxy-phenyl substituent and a dihedral angle of 67.2 (1)° with the benzene substituent on the propenal unit. In the crystal, mol-ecules are connected by weak C-H⋯O hydrogen bonds, forming R 2 (2)(26) and R 2 (2)(28) cyclic dimers that lie about crystallographic inversion centres. These dimers are further linked through C-H⋯O and C-H⋯N hydrogen bonds, forming C(8), C(9), C(10) and C(16) chain motifs. These primary motifs are further linked to form secondary C 2 (2)(15) chains and R 2 (2)(18) rings.

Intermolecular C-H···O and C-H···X interactions in substituted spiroacenaphthylene structures.

In the three spiroacenaphthylene structures 5''-[(E)-2,3-dichlorobenzylidene]-7'-(2,3-dichlorophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(26)Cl(4)N(2)O(2)S, (I), 5''-[(E)-4-fluorobenzylidene]-7'-(4-fluorophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(28)F(2)N(2)O(2)S, (II), and 5''-[(E)-4-bromobenzylidene]-7'-(4-bromophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(28)Br(2)N(2)O(2)S, (III), the substituted aryl groups are 2,3-dichloro-, 4-fluoro- and 4-bromophenyl, respectively. The six-membered piperidine ring in all three structures adopts a half-chair conformation, the thiazolidine ring adopts a slightly twisted envelope and the pyrrolidine ring an envelope conformation; in each case, the C atom linking the rings is the flap atom. In all three structures, weak intramolecular C-H···O interactions are present. The crystal packing is stabilized through a number of intermolecular C-H···O and C-H···X interactions, where X = Cl in (I) and F or S in (II), and C-H···O interactions are observed predominantly in (III). In all three structures, molecules are linked through centrosymmetric ring motifs, further tailored through a relay of C-H···X [Cl in (I), Br in (II) and O in (III)] interactions.

Creatinium hydrogen oxalate.

The crystal structure of the title compound, C(4)H(10)N(3)O(2) (+)·C(2)HO(4) (-), is stabilized by N-H⋯O and O-H⋯O hydrogen bonds. The anions are connected by an O-H⋯O hydrogen bond, leading to C(5) chain extending along c axis. The cations are dimerized around the corners of the unit cell, leading to an R(2) (2)(14) ring motif. This leads to a cationic mol-ecular aggregation at x = 0 or 1 and an anionic mol-ecular aggregation at x = 1/2.

4-Chloro-anilinium 3-carb-oxy-prop-2-enoate.

In the title compound, C(6)H(7)ClN(+)·C(4)H(3)O(4) (-), the cations and anions lie on mirror planes and hence only half of the mol-ecules are present in the asymmeric unit. The 4-chloro-anilinium cation and hydrogen maleate anion in the asymmetric unit are each planar and are oriented at an angle of 15.6 (1)° to one another and perpendicular to the b axis. A characterestic intra-molecular O-H⋯O hydrogen bond, forming an S(7) motif, is observed in the maleate anion. In the crystal, the cations and anions are linked by N-H⋯O hydrogen bonds, forming layers in the ab plane. The aromatic rings of the cations are sandwiched between hydrogen-bonded chains and rings formed through the amine group of the cation and maleate anions, leading to alternate hydro-phobic (z = 0 or 1) and hydro-philic layers (z = 1/2) along the c axis.

Creatininium 2-chloro-acetate.

IN THE TITLE COMPOUND (SYSTEMATIC NAME: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 2-chloro-acetate), C(4)H(8)N(3)O(+)·C(2)H(2)ClO(2) (-), the mol-ecular aggregations are stabil-ized through classical (N-H⋯O) and non-classical (C-H⋯O and C-H⋯N) hydrogen-bonding inter-actions. The cations are linked to the anions, forming ion pairs through two N-H⋯O bonds that produce characteristic R(2) (2)(8) ring motifs. These cation-anion pairs are connected through another N-H⋯O hydrogen bond, leading to an R(4) (2)(8) ring motif. Further weak C-H⋯N inter-actions link the mol-ecules along the a axis, while other C-H⋯O inter-actions generate zigzag chains extending along b.

1-(2,4-Dinitro-phen-yl)-3-phenyl-4-phenyl-sulfanyl-1H-pyrazole.

In the title mol-ecule, C(21)H(14)N(4)O(4)S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, mol-ecules are connected by weak C-H⋯O and C-H⋯N hydrogen bonds into layers parallel to (010).

(E)-5-(4-Methyl-benzyl-idene)-1-phenyl-4,5,6,7-tetra-hydro-1H-indazol-4-one.

In the title compound, C21H18N2O, the non-aromatic six-membered ring adopts a distorted envelope conformation with one of the methyl-ene-C atoms being the flap atom. The dihedral angle between the phenyl and 4-tolyl rings is 75.3 (1)°. The 1,2-diazole ring forms dihedral angles of 41.9 (1) and 65.5 (1)° with the phenyl and 4-tolyl rings, respectively. In the crystal, stabilizing C-H⋯O, C-H⋯π and π-π inter-actions are evident. The calculated Hirshfeld surfaces highlight the prominent role of C-H⋯O inter-actions (8.6%), along with H⋯H (51.7%) and C⋯H/H⋯C (29.2%) surface contacts.

Caffeinium bis-ulfate monohydrate.

IN THE TITLE COMPOUND (SYSTEMATIC NAME: 1,3,7-trimethyl-2,6-dioxo-7H-purin-9-ium hydrogen sulfate monohydrate), C(8)H(11)N(4)O(2) (+)·HSO(4) (-)·H(2)O, the crystal packing is stabilized through N-H⋯O and O-H⋯O hydrogen bonds.

Creatininium cinnamate.

THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 3-phenyl-prop-2-enoate), C(4)H(8)N(3)O(+)·C(9)H(7)O(2) (-), is stabilized by N-H⋯O hydrogen bonding. Cations are linked to anions to form ion pairs with an R(2) (2)(8) ring motif. These ion pairs are connected through a C(2) (2)(6) chain motif extending along the c axis of the unit cell. This crystal packing is characterized by hydro-phobic layers at x âˆ¼ 1/2 packed between hydro-philic layers at x ∼ 0.

Creatininium hydrogen maleate.

In the title compound, C(4)H(8)N(3)O(+)·C(4)H(3)O(4) (-), the cations and anions are linked through N-H⋯O hydrogen bonds making a ionic pair with an R(2) (2)(8) ring motif. These ionic pairs are further connected through another N-H⋯O hydrogen bond, leading to an R(6) (6)(16) ring motif around the inversion centres of the unit cell. These approximately planar aggregates are further connected through weak van der Waals inter-actions in the unit cell. The anions have a characteristic intra-molecular O-H⋯O hydrogen bond with a self-associated ring S(7) motif.

4-Sulfamoylanilinium nitrate.

In the crystal structure of the title compound, C(6)H(9)N(2)O(2)S(+)·NO(3) (-), the cations and anions are connected by N-H⋯O hydrogen bonds into a three-dimensional network.

A triclinic polymorph of 3-nitro-anilinium chloride.

The asymmetric unit of the title compound, C(6)H(7)N(2)O(2) (+)·Cl(-), contains two independent ion pairs. A monoclinic form of the title compound with only one ion pair in the asymmetric unit has been reported previously [Ploug-Sørensen & Andersen (1986). Acta Cryst. C42, 1813-1815]. In the crystal of the title compound, the components are linked into layers parallel to (001) by inter-molecular N-H⋯Cl hydrogen bonds, with alternating hydro-philic and hydro-phobic regions.

2-Nitro-anilinium bromide.

The title compound, C(6)H(7)N(2)O(2) (+)·Br(-), is isomorphous with 2-nitro-anilinium chloride and contains an characteristic intra-molecular N-H⋯O hydrogen bond, forming an S(6) motif. Inter-molecular N-H⋯Br hydrogen bonds occur in the crystal structure. Two zigzag chains of C(2) (1)(4) motifs extend along the b-axis direction. These primary chain motifs inter-sect like a double helix structure, leading to R(6) (3)(12) ring motifs, which are arranged in tandem along the b axis. Hence, hydro-philic layers are generated at z = 1/4 and 3/4, which are sandwiched between alternate hydro-phobic layers across z = 0 and 1/2.

Diethyl 1-benzyl-2,2-dioxo-4-phenyl-3,4,6,7,8,8a-hexa-hydro-1H-pyrrolo-[2,1-c][1,4]thia-zine-1,3-dicarboxyl-ate.

In the title compound, C(26)H(31)NO(6)S, the five-membered pyrrolidine ring adopts an envelope conformation and the six-membered thia-zine ring is in a distorted chair conformation. The crystal packing is stabilized through an inter-molecular C-H⋯O inter-action, generating inversion-related R(2) (2)(10) ring motifs.

2,6-Bis(2-chloro-phen-yl)-4-oxo-3,5-diphenyl-heptane-1,1,7,7-tetra-carbo-nitrile.

In the title compound, C(35)H(24)Cl(2)N(4)O, the phenyl rings are oriented almost parallel to each other, making a dihedral angle of 0.6 (2)°, whereas the chloro-phenyl rings are oriented at a dihedral angle of 28.3 (1)°. The crystal structure is stabilized through an extensive series of C-H⋯N, C-H⋯O and C-H⋯Cl inter-actions. One of the C-H⋯N inter-actions generates an R(2) (2)(12) ring motif around a crystallographic inversion centre. C(5), C(10) and C(12) chain motifs are observed in the unit cell through C-H⋯N and C-H⋯Cl inter-actions. During the structure analysis, it was observed that the unit cell contains large accessible voids, which host disordered solvent mol-ecules. This affects the diffraction pattern, mostly at low scattering angles and was corrected with the SQUEEZE program [Spek, A. L. (2009 ▶). Acta Cryst. D65, 148-155].