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1.  Synthesis and structural studies of a new class of quaternary ammonium salts, which are derivatives of cage adamanzane type aminal 1, 3, 6, 8-tetraazatricyclo[,8]undecane (TATU) 
Novel mono N-alkyl quaternary ammonium salts (3a-f) were prepared using the Menschutkin reaction from the cage adamanzane type aminal 1,3,6,8-tetraazatricyclo[,8]undecane (TATU) and alkyl iodides, such as methyl, ethyl, propyl, butyl, pentyl and hexyl iodide (2a-f), in dry acetonitrile at room temperature.
The structures of these new quaternary ammonium salts were established using various spectral and electrospray ionization mass spectrometry (ESI-MS) analyses. Compound (3b) was also analyzed using X-ray crystallography.
It was noted that alkyl chain length did not significantly affect the reaction because all employed alkyl iodide electrophiles reacted in a similar fashion with the aminal 1 to produce the corresponding mono N-quaternary ammonium salts, which were characterized by spectroscopic and analytical techniques.
PMCID: PMC3189110  PMID: 21933409
2.  1-Heptyl-1,3,6,8-tetraaza­tricyclo­[,8]undecan-1-ium iodide 
The title compound C14H29N4 +·I− salt, was obtained by the reaction of cage adamanzane-type aminal 1,3,6,8-tetra­aza­tricyclo­[,8]undecane with heptyl iodide. In the cation, the bond lengths and angles are within normal ranges, except for one N—C(ring) bond distance of 1.542 (3) Å, which is unexpectedly long compared with related compounds. In the crystal, ions are linked through C—H⋯I hydrogen bonds. The crystal studied was a non-merohedral twin with a minor twin domain of 6.56 (5)%.
PMCID: PMC3201392  PMID: 22064969
3.  Diaqua­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N 1,N 4,N 8,N 11)copper(II) dihepta­noate dihydrate 
The CuII atom in the title salt, [Cu(C10H24N4)(H2O)2][CH3(CH2)5CO2]2·2H2O, is chelated by the four N atoms of the 1,4,8,11-tetra­aza­cyclo­tetra­decane (cyclam) ligand and is coordinated by two water mol­ecules in a tetra­gonally Jahn–Teller-distorted octa­hedral geometry. The CuII atom lies on a center of inversion. The cations, anions and uncoordinated water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a layer structure parallel to (100). The alkyl chain of the anion is disordered over two positions in a 0.82 (1):0.18 (1) ratio.
PMCID: PMC3007509  PMID: 21588132
4.  Diaqua­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N 1,N 4,N 8,N 11)copper(II) bis­(4-methyl­benzoate) monohydrate 
The CuII atom in the title salt, [Cu(C10H24N4)(H2O)2](C8H7O2)2·H2O, is chelated by the four N atoms of the 1,4,8,11-tetra­aza­cyclo­tetra­decane (cyclam) ligand and is coordinated by two water mol­ecules in a Jahn–Teller-type of tetra­gonally distorted octa­hedral geometry. The cations, anions and lattice water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds to form a layer structure parallel to (001).
PMCID: PMC3007233  PMID: 21588135
5.  Diaqua­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N 1,N 4,N 8,N 11)copper(II) bis­(2,3,4,5,6-penta­fluoro­benzoate) dihydrate 
The CuII atom in the title salt, [Cu(C10H24N4)(H2O)2](C6F5CO2)2·2H2O, is chelated by the four N atoms of the 1,4,8,11-tetra­aza­cyclo­tetra­decane (cyclam) ligand and is coordinated by two water mol­ecules in a Jahn–Teller-type tetra­gonally distorted octa­hedral geometry. The CuII atom lies on a center of inversion. The cations, anions and uncoordinated water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a layer structure parallel to (001).
PMCID: PMC3007516  PMID: 21588134
6.  Diaqua­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N 1,N 4,N 8,N 11)copper(II) dideca­noate dihydrate 
The CuII atom in the title salt, [Cu(C10H24N4)(H2O)2][CH3(CH2)8CO2]2·2H2O, is chelated by the four N atoms of the 1,4,8,11-tetra­aza­cyclo­tetra­decane (cyclam) ligand and is coordinated by two water mol­ecules in a Jahn–Teller-type tetra­gonally distorted octa­hedral geometry. The CuII atom lies on a center of inversion. The cations, anions and uncoordinated water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a layer structure parallel to (001).
PMCID: PMC3007572  PMID: 21588133
7.  Diaqua­(1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N 1,N 4,N 8,N 11)copper(II) didodeca­noate dihydrate 
The title compound, [Cu(C10H24N4)(H2O)2][CH3(CH2)10CO2]2·2H2O, consists of one cationic copper(II) complex, two dodeca­noate anions and two water solvent mol­ecules. The CuII atom is located on an inversion center and is chelated by the four aza N atoms of the neutral 1,4,8,11-tetra­aza­cyclo­tetra­decane (cyclam) ligand and by two water mol­ecules in axial positions, giving an octa­hedral coordination geometry, distorted as a consequence of the Jahn–Teller effect. The uncoordinated water mol­ecules link the complex cations and the dodeca­noate counter-ions through O—H⋯O hydrogen bonding, forming a layer structure parallel to (001). Inter­molecular N—H⋯O inter­actions also occur.
PMCID: PMC3089101  PMID: 21754311
8.  1,4,10,13-Tetra­oxa-7,16-diazo­nia­cyclo­octa­decane bis­(1H-pyrrole-2-carboxyl­ate) 
In the title salt, C12H28N2O4 2+·2C5H4NO2 −, the 1,4,10,13-tetra­oxa-7,16-di­aza­cyclo­octa­decane dication possesses inversion symmetry. In the crystal, the pyrrole-carboxyl­ate anions are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked by the dications, via N—H⋯O hydrogen bonds, forming chains propagating along [110].
PMCID: PMC3770382  PMID: 24046667
9.  2,3,5-Triphenyl-2H-tetra­zol-3-ium iodide 
The asymmetric unit of the title mol­ecular salt, C19H15N4 +·I−, contains four 2,3,5-triphenyl-2H-tetra­zol-3-ium cations and five iodide anions, with two of the latter lying on crystallographic inversion centres. In each cation, the tetra­zole ring is essentially planar (r.m.s. deviations = 0.004–0.007 Å). The dihedral angles between the tetra­zole ring and its three attached benzene rings in the four independent cations are: 12.9 (4), 67.0 (4), 48.1 (4); 20.8 (4), 51.1 (4), 62.3 (4); 11.4 (4), 52.3 (4), 47.3 (4) and 6.0 (4), 85.7 (4), 43.5 (4)°. A C—H⋯I hydrogen bond and C—H⋯π inter­actions are observed in the crystal.
PMCID: PMC3435649  PMID: 22969522
10.  Ethyl 23-benzyl-8,11,14-trioxa-23,28,29-triaza­penta­cyclo­[,7.015,20.022,27]nona­cosa-2,4,6,15(20),16,18,21,26-octa­ene-26-carboxyl­ate 
The title compound, C33H35N3O5, is the product of the multicomponent condensation of 1-benzyl-4-eth­oxy­carbonyl­piperidin-3-one with 1,5-bis­(2-formyl­phen­oxy)-3-oxapentane and ammonium acetate. The mol­ecule comprises a penta­cyclic system containing the aza-14-crown-4-ether macrocycle, tetra­hydro­pyrimidine, tetra­hydro­pyridine and two benzene rings. The aza-14-crown-4-ether ring adopts a bowl conformation with a dihedral angle of 62.37 (5)° between the benzene rings. The tetra­hydro­pyrimidine ring has an envelope conformation with the chiral C atom as the flap, whereas the tetra­hydro­pyridine ring adopts a distorted chair conformation. Two amino groups are involved in intra­molecular N—H⋯O hydrogen bonds. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into layers parallel to the ab plane.
PMCID: PMC3629615  PMID: 23634102
11.  catena-Poly[[[(5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N)nickel(II)]-μ-oxido-[dioxidotungstate(VI)]-μ-oxido] tetra­hydrate] 
In the title compound, {[NiWO4(C16H36N4)]·4H2O}n, the NiII ion lies on an inversion center and is octahedrally coordinated by four N atoms of the tetradentate macrocyclic 5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane (L) ligand in the equatorial plane and two O atoms of [WO4]2− anions in axial positions. Each [WO4]2− anion bridges two adjacent [NiL]2+ cations, forming a chain along [001]. The chains are further connected via N—H⋯O, O—H⋯O and C—H⋯O hydrogen-bonding inter­actions, generating a three-dimensional structure.
PMCID: PMC3435596  PMID: 22969469
12.  Bis(nitrato-κO)(5,7,12,14-tetra­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-6,13-diaminium-κ4 N 1,N 4,N 8,N 11)copper(II) dinitrate tetra­hydrate 
In the title compound, [Cu(NO3)2(C14H36N6)](NO3)2·4H2O, the CuII atom, lying on an inversion center, is six-coordinated in a distorted octa­hedral environment by four N atoms from a centrosymmetric 14-membered tetra­aza­cyclo­tetra­decane macrocyclic ligand and two O atoms from two nitrate anions. The supra­molecular network is consolidated by extensive O—H⋯O and N—H⋯O hydrogen-bonding inter­actions.
PMCID: PMC3006849  PMID: 21587749
13.  Bis(hydrazin-1-ium) bis­(μ2-pyridazine-3,6-dicarboxyl­ato)bis­(aqua­lithiate) octa­aqua­bis­(μ3-pyridazine-3,6-dicarboxyl­ato)tetra­lithium 
The unit cell of the title compound, (N2H5)2[Li2(C6H2N2O4)2(H2O)2]·[Li4(C6H2N2O4)2(H2O)8], comprises two centrosymmetric complexes, one double negatively charged and one neutral, and two mono-protonated hydrazine cations. The anionic complex molecule is a dimer, built of a pair of symmetry-related pyridazine-3,6-dicarboxyl­ate ligands and a pair of LiI ions, each coordinated by two N,O-chelating sites donated by a ligand mol­ecule and an aqua O atom at the apical position. The penta­coordination around the LiI ions is partway between a trigonal–bipyramidal and a square-pyramidal arrangement. The two carb­oxy­lic acid groups of the ligand are deprotonated and one carboxyl­ate O atom of each group is not involved in the coordination, and this applies to both the anionic and the neutral complex. The neutral complex molecule is also composed of a pair of LiI ions and a pair of ligand mol­ecules related by a centre of symmetry. They form a dimeric core in which the penta­coordination of the LiI ions includes two N,O-bonding groups donated by two ligands and an aqua O atom. The penta­coordination is described as partway between a trigonal–bipyramidal and a square-pyramidal arrangement. The coordinated carboxyl­ate group is bidentate–bridging, forming with an Li(H2O)3 unit a neutral tetra­meric mol­ecule. The coordination of the tetra­coordinated LiI ion shows a slightly distorted tetra­hedral geometry. An extended system of O—H⋯O and N—H⋯O hydrogen bonds contributes to the stability of the crystal structure.
PMCID: PMC3297271  PMID: 22412461
14.  Bis(2-amino-5-benzyl-3-eth­oxy­carbonyl-4,5,6,7-tetra­hydro­thieno[3,2-c]pyridin-5-ium) bis­(4-meth­oxy­phen­yl)di­phos­phon­ate 
The asymmetric unit of the title salt, 2C17H21N2O2S+·C14H14O7P2 2−, contains half of a centrosymmetric bis­(4-meth­oxy­phen­yl)di­phospho­nate anion and one 2-amino-5-benzyl-3-eth­oxy­carbonyl-4,5,6,7-tetra­hydro­thieno[3,2-c]pyri­din-5-ium cation. In the anion, the O atoms of the di­phospho­nate group are disordered over two positions with equal occupancies. In the cation, the ethyl group is disordered over two orientations with a refined occupancy ratio of 0.753 (5):0.247 (5), and the tetra­hydro­pyridinium ring adopts a distorted half-chair conformation. In the crystal, the ions are linked by C—H⋯O, N—H⋯O and C—H⋯S hydrogen bonds into a three-dimensional network.
PMCID: PMC3998403  PMID: 24765038
15.  1-(Ferrocen-1-ylmeth­yl)-3-methyl­imidazol-3-ium iodide 
The structure of the title compound, [Fe(C5H5)(C10H12N2)]I, consists of a 1-(ferrocen-1-ylmeth­yl)-3-methyl­imidazolium cation which is counter-balanced by an iodide anion. The cyclo­penta­dienyl (Cp) rings of the ferrocene unit have a slightly staggered conformation skewed from an ideal eclipsed conformation by an angle of 3.5 (6)°. The inter­planar angle between the Cp and the imidazole ring is 67.94 (2)°.
PMCID: PMC3588731  PMID: 23468696
16.  Neoaustin: a meroterpene produced by Penicillium sp. 
The title meroterpene neoaustin {systematic name: (1′S,2′R,3S,7′R,9′S,11′S,12′R)-11′-hydr­oxy-2,2,2′,9′,12′-penta­methyl-6′,15′-dimethyl­ene-2,6-dihydro-13′-oxaspiro­[pyran-3,5′-tetra­cyclo­[,11.02,7]penta­deca­ne]-6,10′,14′-trione}, C25H30O6, comprises five rings, three six-membered and two five-membered. The absolute configuration was established based on [αD] = +166.91° (c 1.21, CH2Cl2). In the crystal, the mol­ecules are connected into a supra­molecular helical chain via O—H⋯O hydrogen bonds reinforced by C—H⋯O contacts.
PMCID: PMC2968484  PMID: 21582264
17.  (1,2-Dicarba-closo-dodeca­boran­yl)trimethyl­methanaminium iodide 
The title compound, [1-(CH3)3NCH2-1,2-C2B10H11]+·I− or C6H22B10N+·I−, was obtained by the reaction of (1,2-dicarba-closo-dodeca­boran­yl)dimethyl­methanamine with methyl iodide. The asymmetric unit contains two iodide anions and two (o-carboran­yl)tetra­methyl­ammonium cations. The bond lengths and angles in the carborane cage are within normal ranges, but the N—Cmethyl­ene—Ccage angle is very large [120.2 (2)°] because of repulsion between the carborane and tetra­methyl­ammonium units. In the crystal, ions are linked through C—H⋯I hydrogen bonds.
PMCID: PMC3213586  PMID: 22091163
18.  1-Butyl-3-ethyl-1H-benzimidazol-3-ium tetra­fluoro­borate 
In the title salt, C13H19N2 +·BF4 −, an ionic liquid, the butyl and ethyl substituents bonded to the N atoms of the imidazole ring [r.m.s. deviation = 0.019 (1) Å] adopt equatorial positions. The crystal structure exhibits slipped π–π inter­actions between the imidazole and benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.529 (2) Å]. In the tetra­fluoro­borate anion, the B and F atoms are disordered over two sets of sites with site-occupancy factors of 0.813 (7) and 0.187 (7).
PMCID: PMC3470219  PMID: 23125663
19.  (3R,4S)-3-Methyl-4-phenyl-2-[(R)-1-phenyl­eth­yl]-3,4-di­hydro­isoquinolin-2-ium tetra­fluorido­borate 
The title salt, C24H24N+·BF4 −, is one of two possible dias­tereoisomers having a different configuration of the asymmetric centre in the α-phenyl­ethyl substituent, whose absolute configuration was established to be R. The two phenyl substituents of the cation have a cofacial orientation, albeit with a long centroid–centroid separation of 4.129 (3) Å. The crystal structure exhibits numerous C—H⋯F contacts between counter-ions, with the tetra­fluorido­borate anion surrounded by five iminium cations.
PMCID: PMC3998414  PMID: 24764972
20.  (C-meso-N-meso-5,12-Dimethyl-7,14-diphenyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene)nickel(II) bis­[O,O′-bis­(4-methyl­phen­yl) dithio­phosphate] 
The title complex, [Ni(C24H32N4)](C14H14O2PS2)2, comprises a centrosymmetric [Ni(meso-diphen­yl[14]dien)]2+ dication (meso-diphen­yl[14]dien is C-meso-N-meso-5,12-dimethyl-7,14-diphenyl-1,4,8,11-tetra­aza­cyclo­tetra­deca-4,11-diene) and two O,O′-bis­(4-methyl­phen­yl) dithio­phosphate anions. The NiII ion lies on an inversion center and is chelated by a tetra­amine macrocycle ligand in a slightly distorted NiN4 square-planar geometry. Two S atoms from symmetry-related anions are located in pseudo-axial positions with respect to the NiII ion, with Ni⋯S distances of 3.1869 (8) Å. In the crystal, bifurcated inter­molecular N—H⋯S(S) hydrogen bonds connect cations and pairs of anions into three-component clusters. Weak inter­molecular C—H⋯S hydrogen bonds link these clusters into chains along [100].
PMCID: PMC3011755  PMID: 21589325
21.  1,1′-Methyl­enebis[3-(2,6-diiso­propyl­phen­yl)-3,4,5,6-tetra­hydro­pyrimidin-1-ium] dibromide ethanol monosolvate monohydrate 
In the title methyl­ene-bridged di(tetra­hydro­pyrimidinium) salt, C33H50N4 2+·2Br−·C2H5OH·H2O, the two tetra­hydro­pyrimidinium rings have envelope conformations with the central CH2 C atom as the flap. Their mean planes are inclined to one another by 73.31 (13)° and the attached benzene rings are inclined to one another by 67.39 (15)°. The methylene-C—N bond lengths in the tetra­hydro­pyrimidinium rings are 1.314 (3) and 1.304 (3) Å, values typical for C=N double bonds. The distances between the methyl­ene-bridge C atom and the linked tetra­hydro­pyrimidinium N atom are 1.457 (3) and 1.465 (3) Å, values typical for C—N single bonds. The mol­ecules co-crystallized with H2O and EtOH mol­ecules from the solvent. In the crystal, there is a zigzag chain along [010] of water mol­ecules linked by one of the Br− anions via O—H⋯Br hydrogen bonds. The second Br− anion is hydrogen bonded (O—H⋯Br) to the ethanol solvent mol­ecule. There are also a number of C—H⋯Br and C—H⋯O hydrogen bonds present, leading to the formation of a two-dimensional network lying parallel to the bc plane.
PMCID: PMC3884396  PMID: 24427021
22.  (20S)-Dammar-24-ene-3β,20-diol monohydrate from the bark of Aglaia exima (Meliaceae) 
In the title compound {systematic name: (1R,2R,5R,7R,10R,11R,14S,15R)-14-[(2S)-2-hy­droxy-6-methyl­hept-5-en-2-yl]-2,6,6,10,11-penta­methyl­tetra­cyclo­[,7.011,15]hepta­decan-5-ol monohydrate}, C30H52O2·H2O, the three fused cyclo­hexane rings adopt chair conformations and the hy­droxy substituent of one of these occupies an axial position. The fused cyclo­pentane ring adopts an envelope conformation (with the flap atom being the C atom bearing the methyl group) and the 3-methyl­but-2-enyl portion of its substituent is disordered over three sets of sites in a 0.413 (7):0.250 (7):0.337 (7) ratio. The O atoms of both water mol­ecules occupy special positions of 2 site symmetry. In the crystal, Os—H⋯Ow and Ow—H⋯Os (s = steroid and w = water) hydrogen bonds link hy­droxy groups and water mol­ecules, forming a three-dimensional network. The crystal studied was found to be a non-merohedral twin with a 0.518 (1):0.482 (1) component ratio.
PMCID: PMC3435729  PMID: 22969600
23.  meso-4,4′-Difluoro-2,2′-{[(3aR,7aS)-2,3,3a,4,5,6,7,7a-octa­hydro-1H-1,3-benzimidazole-1,3-di­yl]bis­(methyl­ene)}diphenol 
In the crystal structure of the title compound, C21H24F2N2O2, there are two intra­molecular O—H⋯N hydrogen bonds involving the N atoms of the imidazolidine ring and the hy­droxy groups. The crystal studied was a meso compound obtained by the reaction of the aminal (2S,7R,11S,16R)-1,8,10,17-tetra­aza­penta­cyclo­[,17.02,7.011,16]cosane with 4-fluoro­phenol. The imidazolidine ring has a twisted conformation with a CH—CH—N—CH2 torsion angle of 44.99 (14)° and, surprisingly, the lone pairs of the N atoms are disposed in a syn isomerism, making the title compound an exception to the typical ‘rabbit-ear effect’ in 1,2-diamines. In the crystal, molecules are linked via C—H⋯F hydrogen bonds, forming chains along the c-axis direction. These chains are linked via another C—H⋯F hydrogen bond, forming a three-dimensional network.
PMCID: PMC3569752  PMID: 23424498
24.  A crystallographically isolated dimeric hydrolyzed chloro­phosphazene dianion 
Single crystals of the title compound bis[bis­(1-ethyl-3-methyl-imidazol-2-yl­idene)silver(I)] 1,5,5,7,11,11-hexa­chloro-2,8-di­oxa-4,6,10,12,13,14-hexa­aza-1λ5,3,5λ5,7λ5,9,11λ5-hexa­phospha­tricyclo­[,7]tetra­deca-1(13),4,7(14),10-tetra­ene-6,12-diide 3,9-dioxide, [Ag(C6H10N2)2](Cl6N6O4P6)0.5, were isolated from the reaction of the silver N-heteocyclic carbene complex [Ag(C6H10N2)2]Cl and hexa­chloro­cyclo­triphos­phazene [NPCl2]3 in the presence of water. The asymmetric unit contains one silver carbene cation with the carbene ligands bound to the Ag(I) in an almost linear arrangement and one half of a hydrolyzed phosphazene dianion. The second cation and additional half of the anion are generated by an inversion center.
PMCID: PMC2968009  PMID: 21581471
25.  Bis(dimethyl­ammonium) 3,3′-dicarb­oxy-5,5′-(5,7,12,14-tetra­oxo-6,13-diaza­tetra­cyclo­[,16.011,15]hexa­deca-1,3,8,10,15-penta­ene-6,13-di­yl)dibenzoate dihydrate 
The title compound, 2C2H8N+·C30H12N2O12 2−·2H2O, comprises dimethyl­ammonium cations, 3,3′-dicarb­oxy-5,5′-(5,7,12,14-tetra­oxo-6,13-diaza­tetra­cyclo­[,16.011,15]hexa­deca-1,3,8,10,15-penta­ene-6,13-di­yl)dibenzoate dianions and water mol­ecules. The dianion is situated on a crystallographic inversion centre. Two very strong symmetry-restricted O⋯H⋯O hydrogen bonds are present which are situated about the crystallographic inversion centres. In one of these hydrogen bonds, the H atom is situated at its centre, while in the other one the H atom is disordered about its centre. Both H atoms are involved in the chain-like C 2 2(16) motif, and not in a more common motif R 2 2(8) that is composed of a pair of hydrogen carboxyl­ates with the H atoms situated about the centre between the pair of O atoms. In the crystal, inter­action of these hydrogen bonds results in formation of anionic layers of dianions parallel to (-111). The water mol­ecules donate their H atoms to one of two of the carboxyl­ate O atoms, forming strong hydrogen bonds. The dimethyl­ammonium donates a bifurcated hydrogen bond to an oxo group of the dianion, forming weak hydrogen bonds. All the hydrogen bonds form a three-dimensional hydrogen-bonded network.
PMCID: PMC3393979  PMID: 22798844

Results 1-25 (223655)