rac-4-Carbamoylpiperidinium cis-2-carboxycyclohexane-1-carboxylate

In the title salt, racemic C6H12N2O+ C8H11O4- from the reaction of cis-cyclohexane-1,2-dicarboxylic anhydride with isonipecotamide, the cations are linked into duplex chain substructures through both centrosymmetric cyclic head-to-head 'amide motif' hydrogen-bonding associations [graph set R2/2(8)] and 'side-by-side' R2/2(14) associations. The anions are incorporated into the chains through cyclic R3/4(10) interactions involving amide and piperidinium N-H...O(carboxyl) hydrogen bonds which, together with inter-anion carboxylic acid O-H...O(carboxyl) hydrogen bonds, give a two-dimensional layered structure extending along (011).

Resolution of the chiral (1R,2S) enantiomer of cis-cyclohexane-1,2-dicarboxylic acid in the brucinium salt 2,3-dimethoxy-10-oxostrychnidinium (1R,2S)-2-carboxycyclohexane-1-carboxylate dihydrate

The structure of the 1:1 brucinium salt of cis-cyclohexane-1,2-dicarboxylic acid, 2,3-dimethoxy-10-oxostrychnidinium (1R,2S)-2-carboxycyclohexane-1-carboxylate dihydrate, has revealed the resolved (1R,2S) enantiomer of the acid. Crystals of the compound are orthorhombic, space group P212121, with unit cell dimensions a = 8.1955(3), b = 12.4034(3), c = 29.9073(9)Å, and Z = 4. The asymmetric unit comprises the brucinium cation, the hydrogen cis-cyclohexane-1,2-dicarboxylate cation, in which the carboxylate group is disordered over two sites (58, 42%), and two water molecules of solvation, one of which is occupies two 50% occupancy sites. The classic undulating brucinium cation substructures are present with the anion and the water molecules occupying the interstitial cavities and are hydrogen-bonded to them in a two-dimensional network structure.

ortho-Bromo(propa-1,2-dien-1-yl)arenes : substrates for domino reactions

o-Bromo(propa-1,2-dien-1-yl)arenes exhibit novel and orthogonal reactivity under Pd catalysis in the presence of secondary amines to form enamines (concerted Pd insertion, intramolecular carbopalladation, and terminative Buchwald–Hartwig coupling) and of amides to form indoles (addition, Buchwald–Hartwig cyclization, and loss of the acetyl group). The substrates for these reactions can be accessed in a reliable and highly selective two-step process from 2-bromoaryl bromides.

Axial binding of 2-methylimidazole to the tetraarylcarboxylatodiruthenium (II, III) core: X-ray crystal structure of [Ru-2(O2CC6H4-p-OMe)(4)(2-mimH)(2)](ClO4). 1.75CH(2)Cl(2).H2O

Diruthenium (II. III) complexes of the type [Ru-2(O2CAr)(4) (2-mimH)(2)](ClO4) (Ar = C6H4-p-X : X=OMe,1, X=Me, 2, 2-mimH=2-methylimidazole) have been isolated from the reaction of Ru2Cl(O2CAr)(4) with 2-mimH in CH2Cl2 followed by the addition of NaClO4. The crystal structure of 1.1.75CH(2)Cl(2).H2O has been determined. The crystal belongs to the monoclinic space group p2(1)/c with the following unit cell dimensions for the C40H40N4O16ClRu2.1.75CH(2)Cl(2).H2O (M = 1237.0) : a = 12.347(3)Angstrom, b = 17.615(5)Angstrom, c = 26.148(2)Angstrom,beta = 92.88(1)degrees. v = 5679(2)Angstrom(3). Z=4, D-c = 1.45 g cm(-3). lambda(Mo-K-alpha) = 0.7107 Angstrom, mu(Mo-K-alpha) = 8.1 cm(-1), T = 293 K, R = 0.0815 (wR(2) = 0.2118) for 5834 reflections with 1 > 2 sigma(I). The complex has a tetracarboxylatodiruthenium (II, III) core and two axially bound 2-methylimidazole ligands. The Ru-Ru bond length is 2.290(1)Angstrom. The Ru-Ru bond order is 2.5 and the complex is three-electron paramagnetic. The complex shows an irreversible Ru-2(II,III)-->Ru-2(Il,II) reduction near -0.2 V vs SCE in CH2Cl2-0. 1 MTBAP. The complexes exemplify the first adduct of the tetracarboxylatodiruthenium (II,III) core having N-donor ligands

Acid-catalysed cyclisations: structures of novel products isolated in the reaction of 2-[3-(2,6-dimethoxyphenyl)but-2-enyl]-2-methylcyclopentane-1,3-dione with MeOH-HCl

Reaction of the title compound (1a) with anhydrous MeOH-HCl gave 2-endo-(2,6-dimethoxyphenyl)-2-exo-methyl-5-methylbicyclo[3.2.1]octane-6,8-dione (3a), 1,5,14-timethoxy-5,8-seco-6,7-dinorestra-1,3,5(10),9(11)-tetraen-17-one (4), 1,5-dimethoxy-5,8-seco-6,7-dinorestra-1,3,5(10),8,14-pentaen-17-one (5), and 3,4,5,6-tetrahydro-2,7-dimethoxy-3,6-dimethyl-3,2,6-(13-oxopropan[1]yI[3]ylidene)-2H-1-benzoxocin (6). Structures assigned to compounds (3a), (4), and (6) are based on spectral data. The exo-tricyclic acetal structure (6) was further confirmed by the analysis of the 1H n.m.r. spectra of the isomeric alcohols (11) and (12), obtained by sodium borohydride reduction of (6).

A 1h And 13c Magnetic Resonance And Infrared Spectroscopic Study Of Coordinated 2-Aminocyclopentene-1-Dithiocarboxylic Acid And Its S-Methyl Ester

The ligating properties of 2-aminocyclopentene-1-dithiocarboxylic acid and its S-methyl esters were investigated. Complexes with Zn(II), Cd(II) and Hg(II) halides were synthesized and characterized by infrared and proton and carbon-13 NMR studies. The results are concordant with a bidentate coordination of the -CS2 group to the metal ions

Synthesis and structure of mixed ligand isonitroso-β-ketoiminenickel(II) complexes. Crystal structure of (1-ethoxycarbonyl-2-npropylimino-1-propanoneoximato) (1-methoxycarbonyl-2-imino-1-propanoneoximato)nickel(II)

Mixed ligand complexes of the type Ni(R-AB)(AC') and Ni(R-AC)(AB') where AB/AC denote N-bonded isonitroso- [3-ketoimino ligands, AB'/AC' denote the corresponding Obonded ligands and R = Me, Et, n-Pr are synthesised and characterised. The complexes are neutral with square planar geometry around nickel(II). The bonding isomerism of the isonitroso group is discussed on the basis of i.r. and 1H n.m.r. studies. The crystal structure of the title complex, Ni(n-Pr-IEAI)(IMAI') has been determined from diffractometer data by Patterson and Fourier methods and refined by least squares to R = 0.088 for 2209 observed reflections. Unit cell constants are: a = 11.945(2), b = 22.436(7), c = 13.248(5) ~, [3 = 95.13(2) ~ The space group is P2Jc with Z = 8. Niekel(II) has a square planar coordination of two imine nitrogens, an isonitroso-nitrogen (from n-Pr-IEAI) and another isonitrosooxygen (from IMAI').

Structure of 7-methyl-1(2)a,1(6)a,3(4)a-trihomocubane-1(6)a,3(4)a-dione,star-c12h12o2- a case of enantiomeric and rotational disorder

M r = 188.22, monoclinic, P21/n, a = 6.219 (2), b= 10.508 (2), c=7.339 (1)A, t= 107.64 (2) °, V= 457 ,/k 3, Z = 2, D m - - 1.360 (3), D x = 1.366 (2)Mgm -3, ~,(MoKa) = 0.7107/~, #= 0.053 mm -I, F(000) = 200, T= 293 K. Final R = 5.8% for 614 significant reflections. The molecule, which does not possess a centre of symmetry, occupies a crystallographic centre of symmetry because of the statistical enantiomeric and rotational disorder. Latticeenergy calculations, based on van der Waals attractive and repulsive potentials, clearly show minima at the observed disordered positions.

The structure of 3-(2-methoxyphenyl)-1,1,2,2-cyclopropanetetracarbonitrile

Crystals of C I4HsN40 are monoclinic, space group P21, Unit-cell constants are a = 13.241(4), b = 7.446 (2), c = 6.436 (2)/A, B= 93.23 (2) °. V= 633.5 /A3, Z = 2, Dob s = 1.30 (flotation), Dealt = 1.300 Mg m -3 and #(Cu Ka) = 0.72 mm -1. The structure, solved by direct methods, has been refined to an R value of 3.5% using 1245 intensity measurements. The combined effect of electron-withdrawing and –donating substituents on the geometry of the cyclopropane ring is discussed.

Charge transfer complexes of crown ethers with neutral organic gyama-acceptor, 2-dicyanoethylene 1,3-indane dione

The interaction of benzo-15-crown-5, dibenzo-18-crown-6 and dibenzo-24-crown-8 with 2-dicyanoethylene 1,3-indane dione in CH2Cl2 has been described in terms of the formation of 1 : 1 molecular complexes. The magnitude of association constants and thermodynamic parameters indicate cooperative interactions of oxygens with the acceptors. The 1H and 13C NMR spectra of the complexes show that gyama-gyama interactions are a major source of ground state stabilization in these complexes.

Komplexe von Lanthanidnitraten mit 2-Methylpyridin-1-oxid

Complexes of lanthanide nitrates with 2-methylpyridine-1-oxide of the formuleLn(2-MePyO)3(NO3)3 whereLn=Nd, Sm, Tb, Dy and Yb and La(2-MePyO)3(NO3)3·2H2O have been prepared and characterized by chemical analyses, IR spectral, conductance andDTA data. IR spectral data have been interpreted in terms of the coordination of the ligand to the metal through the oxygen of the N–O group. Conductance and IR spectral data show that all the nitrate groups are bidentate and that two of the nitrate groups are bound to the metal in a different manner than the other.

Complexes of lanthanide iodides with 4-methylpyridine-1-oxide and 2-methylpyridine-1-oxide

Complexes of lanthanide iodides with 4-methylpyridine-1-oxide and 2-methylpyridine-1-oxide of the formulae Ln(4-MePyO)8I3.xH2O (x=0 or 2) and Ln(2-MePyO)5I3.xH2O (x=0, 1 or 3) have been prepared and characterized by analyses, conductance, infrared and proton NMR data. Infrared spectra of the complexes indicate that the coordination of the ligand to the metal ion takes place through the oxygen of the N-O group of the ligand. Proton NMR data for the paramagnetic complexes indicate that both contact and pseudocontact interactions are responsible for the isotropic shifts. Proton NMR spectra of the 2-methylpyridine-1-oxide complexes indicate a restricted rotation of the ligand about the N-O group.