Bis Hydrogen Research Articles

A very short O-H⋯O hydrogen bond in the structure of clozapinium hydrogen bis-(3,5-di-nitro-benzoate).

In the title salt {systematic name: 4-[6-chloro-2,9-di-aza-tri-cyclo-[9.4.0.03,8]penta-deca-1(15),3(8),4,6,9,11,13-heptaen-10-yl]-1-methyl-piperazin-1-ium 3,5-di-nitro-benzoate-3,5-di-nitro-benzic acid (1/1)}, C18H20ClN4 +·C7H3N2O6 -·C7H4N2O6, there is a very short, asymmetric, O-H⋯O hydrogen bond [O⋯O = 2.453 (3) Å] within the anion. The oxygen atoms of one of the nitro groups of the anion are disordered over two sets of sites having occupancies of 0.56 (3) and 0.44 (3). The fused tricyclic portion of the cation adopts a butterfly conformation, with a dihedral angle of 45.59 (6)° between the planes of the two aryl rings. In the crystal, a combination of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds links the component species into a three-dimensional framework. Comparisons are made with the structures of some related compounds.

Co-crystallization of 3,5-di-nitro-benzoic acid with two anti-psychotic agents: a simple 1:1 salt with trihexyphenidyl and a 1:2 acid salt containing a very short O-H⋯O hydrogen bond with chlorprothixene.

Co-crystallization of racemic 1-cyclo-hexyl-1-phenyl-3-(piperidin-1-yl)propan-1-ol (trihexyphenid-yl) with 3,5-di-nitro-benzoic acid gives a simple 1:1 salt, namely 1-(3-cyclo-hexyl-3-hy-droxy-3-phenyl-prop-yl)piperidin-1-ium 3,5-di-nitro-benzoate, C20H32NO+·C7H3N2O6 -, (I), whereas a similar co-crystallization using (Z)-3-(2-chloro-9H-thioxanthen-9-yl)-N,N-di-methyl-propan-1-amine (chlorprothixene) gives a 1:2 acid salt, namely (Z)-3-(2-chloro-9H-thioxanthen-9-yl)-N,N-di-methyl-propan-1-aminium hydrogen bis-(3,5-di-nitro-benzoate), C18H19ClNS+·[H(C7H3N2O6)2]-, (II), the anion of which contains a very short O-H⋯O hydrogen bond, with dimensions O-H = 1.04 (3) Å, H⋯O = 1.41 (3) Å, O⋯O= 2.4197 (15) Å and O-H⋯O = 161 (3)°. In the cation of (I), the cyclo-hexyl and piperidyl rings both adopt chair conformations, whereas in the cation of (II), the central heterocyclic ring adopts a boat conformation, so that the dihedral angle between the two aryl rings is 41.56 (4)°. A combination of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds links the ions of (I) into a complex chain of rings, and these chains are linked into sheets by π-π stacking inter-actions between inversion-related pairs of anions. In compound (II), a different combination of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds links the ions into sheets. Comparisons are made with some related structures.

Stoichiometric and polymorphic salts of hexa-methyl-ene-tetra-minium and 2-chloro-4-nitro-benzoate.

Four mol-ecular salts made from hexa-methyl-ene-tetra-minium and 2-chloro-4-nitro-benzoate have been synthesized and are reported, namely ammonium hexa-methyl-ene-tetra-minium bis-(2-chloro-4-nitro-benzoate), NH4+·C6H13N4+·2C7H3ClNO4-, (I), hexa-methyl-ene-tetra-minium hydrogen bis-(2-chloro-4-nitro-benzoate), 0.5C6H13N4+·C7H3.50ClNO4-, (II), hexa-methyl-ene-tetra-minium 2-chloro-4-nitro-benzoate, C6H13N4+·C7H3ClNO4-, (IIIa) and (IIIb). All four mol-ecular salts show N+-H⋯O- hydrogen bonding. Salt (I) crystallized out with an NH4+ counter-ion which came from decomposition of 50% of the hexa-methyl-ene-tetra-minium cation in solution. (II) shows an unusual asymmetric unit, with both a hexa-methyl-ene-tetra-minium cation and a partially deproton-ated 2-chloro-4-nitro-benzoate anion. Salts (IIIa) and (IIIb) are polymorphs of each other. This work shows that hexamethylenetetramine only protonates once, even in the presence of excess acid.

Ammonium hydrogen bis[(3-chloro-2-methylphenoxy)acetate

In the structure of the ammonium hydrogen salt of (3-chloro-2-methylphenoxy)acetic acid, NH4+·C18H17Cl2O6−, the dimeric anion comprises two inversion-related head-to-head components linked through a short symmetric carboxyl O...H...O hydrogen bond in which the delocalized acid H atom lies on an inversion centre. The ammonium cation is disordered over another inversion centre. The crystal structure is based on a number of inter-species ammonium N—H...O hydrogen-bonding associations, giving two-dimensional layers lying parallel to (001).

Preparation of 1,4-cyclohexanedimethanol by selective hydrogenation of a waste PET monomer bis(2-hydroxyethylene terephthalate)

A new approach is developed for the preparation of 1,4-cyclohexanedimethanol (CHDM) by hydrogenation of bis(2-hydroxyethylene terephthalate) (BHET) obtained from waste poly(ethylene terephthalate) (PET), and the 100% conversion of BHET and 78% yield of CHDM were achieved.

Neutral and Cationic Zirconium Hydrides Supported by a Dianionic (NNNN)-Type Macrocycle Ligand

Hydrogenation of bis(trimethylsilylmethyl) zirconium complex [Zr(Me2TACD)(CH2SiMe3)2] (1), prepared by reacting [Zr(CH2SiMe3)4] with 1,7-dimethyl-1,4,7,10-tetraazacyclododecane (Me2TACD)H2, gave dinuclear alkyl hydride complex [Zr(Me2TACD)(CH2SiMe3)2(μ-H)2Zr(Me2TACD)] (2). According to NMR spectroscopic and single-crystal X-ray diffraction studies, 2 exhibits a Cs-symmetrical structure with two distinct zirconium centers, one eight- and the other seven-coordinate, bridged by an amido donor and two hydrides. Abstraction of the trimethylsilylmethyl groups by the weak Bronsted acid [NEt3H][B(3,5-C6H3Cl2)4] gave the monocationic mono(alkyl) dihydride [Zr(Me2TACD)(CH2SiMe3)(μ-H)2Zr(Me2TACD)][B(3,5-C6H3Cl2)4] (3) and the dicationic hydride complex [Zr(Me2TACD)(THF)2(μ-H)2Zr(Me2TACD)][B(3,5-C6H3Cl2)4]2 (4). X-ray crystallography of the cationic complexes 3 and 4 revealed a Cs-symmetrical dinuclear structure derived from that of 2.

Two-dimensional coordination polymeric structures in caesium complexes with ring-substituted phenoxyacetic acids.

The two-dimensional polymeric structures of the caesium complexes with the phenoxyacetic acid analogues (4-fluorophenoxy)acetic acid, (3-chloro-2-methylphenoxy)acetic acid and the herbicidally active (2,4-dichlorophenoxy)acetic acid (2,4-D), namely poly[[μ5-(4-fluorophenoxy)acetato][μ4-(4-fluorophenoxy)acetato]dicaesium], [Cs2(C8H6FO3)2]n, (I), poly[aqua[μ5-(3-chloro-2-methylphenoxy)acetato]caesium], [Cs(C9H8ClO3)(H2O)]n, (II), and poly[[μ7-(2,4-dichlorophenoxy)acetato][(2,4-dichlorphenoxy)acetic acid]caesium], [Cs(C8H5Cl2O3)(C8H6Cl2O3)]n, (III), are described. In (I), the Cs(+) cations of the two individual irregular coordination polyhedra in the asymmetric unit (one CsO7 and the other CsO8) are linked by bridging carboxylate O-atom donors from the two ligand molecules, both of which are involved in bidentate chelate Ocarboxy,Ophenoxy interactions, while only one has a bidentate carboxylate O,O'-chelate interaction. Polymeric extension is achieved through a number of carboxylate O-atom bridges, with a minimum Cs···Cs separation of 4.3231 (9) Å, giving layers which lie parallel to (001). In hydrated complex (II), the irregular nine-coordination about the Cs(+) cation comprises a single monodentate water molecule, a bidentate Ocarboxy,Ophenoxy chelate interaction and six bridging carboxylate O-atom bonding interactions, giving a Cs···Cs separation of 4.2473 (3) Å. The water molecule forms intralayer hydrogen bonds within the two-dimensional layers, which lie parallel to (100). In complex (III), the irregular centrosymmetric CsO6Cl2 coordination environment comprises two O-atom donors and two ring-substituted Cl-atom donors from two hydrogen bis[(2,4-dichlorophenoxy)acetate] ligand species in a bidentate chelate mode, and four O-atom donors from bridging carboxyl groups. The duplex ligand species lie across crystallographic inversion centres, linked through a short O-H···O hydrogen bond involving the single acid H atom. Structure extension gives layers which lie parallel to (001). The present set of structures of Cs salts of phenoxyacetic acids show previously demonstrated trends among the alkali metal salts of simple benzoic acids with no stereochemically favourable interactive substituent groups for formation of two-dimensional coordination polymers.

Phase Transition Triggered by Ordering of Unique Pendulum-Like Motions in a Supramolecular Complex: Potassium Hydrogen Bis(dichloroacetate)-18-Crown-6

A novel supramolecular phase change material (PCM) potassium hydrogen bis(dichloroacetate)-18-crown-6 (1), which undergoes a reversible second-order phase transition at 181.8 K (Tc), has been successfully synthesized and grown as bulk crystals. DSC measurements confirm its reversible phase transition with a thermal hysteresis of 1.6 K. Dielectric permittivities also display obvious anomalies approaching Tc, being characteristic for the reversible phase transition. Variable-temperature X-ray single-crystal diffractions demonstrate that 1 behaves as a molecular rotor above room temperature in which the chlorine atoms rotate around the C–C axis of the CHCl2COO–/CHCl2COOH exhibiting distinct pendulum-like motions, and the (18-crown-6)·K+ part acts as a stator. Further studies reveal that the origin of its phase transition was ascribed to the moving close together of the whole set molecules from the original position, which is induced by the order–disorder transformation of the pendulum-like motions of the CHC...

Synergistic extraction of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate and bis(diphenylphosphino)methane dioxide

Synergistic extraction of europium and americium into nitrobenzene by using hydrogen dicarbollylcobaltate and bis(diphenylphosphino)methane dioxide

Water-in-oil Microemulsion Formation with Aqueous Cn-TAB Solution and H-AOT/Isooctane Solution

Abstract Aqueous Cn-TAB (n = 8, 10, and 12; octyl-, decyl-, and dodecyltrimethylammonium bromide) solution and isooctane solution of H-AOT (hydrogen bis(2-ethylhexyl) sulfosuccinate) were mixed using a vortex mixer to produce a water-in-oil (W/O) microemulsion. The microemulsion was formed with the critical amount of Cn-TAB; the order of the critical amount was C12-TAB < C10-TAB < C8-TAB. A possible cause for the microemulsion formation was proposed based on the screening of the electrostatic repulsion between negatively charged AOT’s polar headgroups by the positively charged Cn-TAB’s polar headgroups, the hydrophobic interaction between hydrocarbon chains, and hydrated water around AOT’s polar headgroup.

Virtually Nonexistent Correlation between the OH Stretching Frequency and the Instantaneous Geometry in the Short Hydrogen Bond of Sodium Hydrogen Bis(sulfate): Advanced Chemometrics Analysis

We examined the correlation between the dynamically sampled anharmonic frequency of the OH stretching motion and the corresponding instantaneous geometric parameters associated with the structure of crystalline sodium hydrogen bis(sulfate), which is a benchmark system with an extremely short hydrogen bond. We analyzed the trajectory obtained by a conventional Car-Parrinello molecular dynamics simulation, followed by an a posteriori quantization of the proton motion. For statistical analysis we applied the established methodologies of multiple linear regression, principal component analysis, principal component regression, and Kohonen neural networks. No simple correlation scheme between the OH stretching frequency and any particular geometry parameter (or their combination) was found. In comparison to the established correlation schemes (e.g., Mikenda and Novak) that consider a series of systems, our study provides a complementary insight into the nature of hydrogen bonding of a single system, in the sense that it considers the important aspects of fluctuations of the environment and the resulting broadening of the OH stretching band, which cannot be adequately assessed by experiment. The absence of appreciable correlations gives strong evidence of the extreme complexity of short hydrogen bonding.

Hexaaquacobalt(II) bis[hydrogen bis(4-carboxyphenylphosphonate)] dihydrate

The Co(II) ion in the title complex salt, [Co(H(2)O)(6)](C(14)H(13)O(10)P(2))(2)·2H(2)O or [Co(H(2)O)(6)][H(C(7)H(6)O(5)P)(2)]·2H(2)O, resides on an inversion centre and exhibits an octahedral environment formed by six aqua ligands. Two unique acid residues share an H atom between their phosphonate groups, forming a complex monoanion with a very short (P)O···H···O(P) hydrogen bond of 2.435 (2) Å. The crystal structure is layered and consists of thick organic bilayers with hydrated metal [Co(H(2)O)(6)](2+) ions arranged between them. The interior of the bilayer is occupied by the aromatic portions of the complex monoanions and the carboxyl groups, which form hydrogen-bonded R(2)(2)(8) ring motifs. The phosphonate groups are arranged outwards in order to form the hydrogen-bonded surfaces of the bilayer. Electrostatic and multiple hydrogen-bond interactions, established between the coordination and solvent water molecules and the phosphonate O atoms, hold neighbouring bilayers together.

Platinum(II)-catalyzed intramolecular cyclization of alkynylbenzonitriles: synthesis of 1-alkoxyisoquinolines and isoquinolones

A facile synthesis of a series of 1-alkoxyisoquinolines and (2 H)-isoquinolones by an intramolecular 6- endo- dig cyclization of ortho-alkynylbenzonitriles in the presence of a catalytic amount of hydrido(dimethylphosphinous acid-κP)[hydrogen bis(dimethylphosphinito-κP)]platinum(II) in various alcohols at 65–90 °C is described for the first time.

Hydrogen bis(1,2,4-triazole)] 1,2,4-triazolium bis(3-carboxy-4-hydroxybenzenesulfonate) 1,2,4-triazole disolvate

The title compound, C2H4N3 +·[H(C2H3N3)2]+·2C7H5O6S−·2C2H3N3, consists of two types of 1,2,4-triazole monocation, one protonated at the 2-site lying across a twofold axis and the other protonated at the 4-site with the H atom disordered over a center of symmetry, a 5-sulfosalicylate anion and a neutral 1,2,4-triazole mol­ecule. The component ions are linked into a three-dimensional network by a combination of N—H⋯O, N—H⋯N, O—H⋯O, O—H⋯N, C—H⋯O and C—H⋯N hydrogen bonds. In addition, benzene–benzene π–π inter­actions of 3.942 (2) Å [inter­planar spacing = 3.390 (2) Å] and C—O⋯π (3.331 Å) inter­actions are observed.

Redetermination of di-μ-hydroxido-bis[diaquachloridodioxidouranium(VI)] from single-crystal synchrotron data

The title compound, [(UO2)2Cl2(OH)2(H2O)4], was obtained unintentionally as the product of an attempted reaction between uranium(VI) oxide dihydrate, UO3·2H2O, and hydrogen bis­(trifluoro­methyl­sulfon­yl)imide (HTf2N), in an experiment to obtain crystals of uranyl bis­(trifluoro­methyl­sulfon­yl)imide, UO2(Tf2N)2·xH2O. The structure consists of neutral dimers of uranyl (UO2 2+) units, double bridged by OH− anions. Each uranyl unit is surrounded by one Cl and four O atoms, which form an irregular penta­gon, in a plane perpendicular to the linear uranyl groups. The coordination geometry around each U atom can be considered to be distorted penta­gonal-bipyramidal. In the crystal structure the uranyl dimers are connected to each other by hydrogen-bonding inter­actions [O⋯Cl = 3.23 (1) Å].

Protonation of electroneutral p-tert-butylcalix[4]arenetetraacetic acid

AbstractUsing 1 H NMR spectroscopy together with density functional theoretical calculations, it is shown that electroneutral p-tert-butylcalix[4]arenetetraacetic acid forms an equimolar complex with a proton in the form of the H 3 O + ion in nitrobenzene-d 5 . Protons were offered by hydrogen bis(1,2-dicarbollyl)cobaltate and converted to hydroxonium ions by traces of water. In the resulting complex, the H 3 O + cation is bound by strong hydrogen bonds to two phenoxy oxygen atoms of the parent calix[4]arene ligand and to one carbonyl oxygen of the corresponding COOH group of this ligand.Graphical Abstract[IMAGE]

Hexane-1,6-diaminium chloride [hydrogen bis(chloroacetate)

In the structure of the title compound, C(6)H(18)N(2)(2+).H(C(2)H(2)ClO(2))(2)(-).Cl(-), the hexane-1,6-diaminium dication is disordered over two sets of positions, with almost equal occupancies. Both alternative positions of the dication are in the fully extended conformation, situated on an inversion centre at (3/4, 1/4, 1/2). Two chloroacetic acid moieties, related by another centre of symmetry at (1/2, 1/2, 1/2), are connected by a very short symmetrical O...H...O hydrogen bond [O...O = 2.452 (2) A], with the H atom at the centre of inversion. These two fragments thus effectively form the hydrogen bis(chloroacetate) monoanion, and the overall charge is balanced by an additional chloride anion which resides on a twofold axis. The ions form a layer structure, with alternating layers of dications and anions running along the [101] direction, linked via hydrogen bonds. There are two N-H...O interactions and two N-H...Cl(-) interactions.

NMR and theoretical study of the cooperative interaction of hydrated proton with dibenzo‐24‐crown‐8

Interaction of hydrated protons (HPs) with dibenzo-24-crown-8 (DBC in nitrobenzene-d(5) was studied by (1)H and (13)C NMR under assistance of ab initio-density functional theory (DFT) quantum calculations. HPs were afforded by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) with 3.5 M excess of H(2)O. The forming of a complex between HP and DBC leads to marked and additive relative shifts of both (1)H and (13)C signals. This was utilized for the estimation of the stabilization constant K of the complex. Its value is at least 10(6) l/mol, which agrees with the result of independent extraction method (log K = 6.3). Using absolute integral intensities of the HP signal in a water-saturated system, it was shown that the form of HP present in the complex must be H(5)O(2)(+), in accord with formerly published structure of the complex in crystalline form. The investigation of the dynamics of exchange between bound and free DBC by transverse relaxation using variably spaced pulses in the Carr-Purcell-Meiboom-Gill (CPMG) sequence or on-resonance rotating-frame relaxation with variable spin-lock field intensity was partly hampered by the fast relaxation of some signals in the complex because of relative immobilization of its internal motions. In order to remove these effects, a pulse sequence dipolar interaction-free transverse relaxation (DIFTRE) for static DIFTRE was devised and the MLEV17 pulse sequence with high intensity of electromagnetic field was used in a separate series of experiments. Using the results of these latter experiments, the correlation time of exchange was established to be about 0.8 ms, which complied with the shape of the spectra. The accompanying ab initio DFT calculations showed that the apparent symmetry of the molecules of both DBC and its complex with H(5)O(2)(+) was probably the result of averaging of energetically close conformations (five for DBC and four for the complex). Both NMR and the calculations show that the basic mode of binding of the ion in the complex is analogous to that found in crystal but the most pronounced conformation is slightly different.

Rac-3-Benzoyl-2-methylpropionic acid and its organic salts: possibilities of Yang photocyclization in crystals

The analysis of the crystal structures of rac-3-benzoyl-2-methylpropionic acid, C(11)H(12)O(3), (I), morpholinium rac-3-benzoyl-2-methylpropionate monohydrate, C(4)H(10)NO(+).C(11)H(11)O(3)(-).H(2)O, (II), pyridinium [hydrogen bis(rac-3-benzoyl-2-methylpropionate)], C(5)H(6)N(+).(H(+).2C(11)H(11)O(3)(-)), (III), and pyrrolidinium rac-3-benzoyl-2-methylpropionate rac-3-benzoyl-2-methylpropionic acid, C(4)H(10)N(+).C(11)H(11)O(3)(-).C(11)H(12)O(3), (IV), has enabled us to predict and understand the behaviour of these compounds in Yang photocyclization. Molecules containing the Ar-CO-C-C-CH fragment can undergo Yang photocyclization in solvents but they can be photoinert in the crystalline state. In the case of the compounds studied here, the long distances between the O atom of the carbonyl group and the gamma-H atom, and between the C atom of the carbonyl group and the gamma-C atom preclude Yang photocyclization in the crystals. Molecules of (I) are deprotonated in a different manner depending on the kind of organic base used. In the crystal structure of (III), strong centrosymmetric O...H...O hydrogen bonds are observed.

Protonation of Tetrapropoxy-4-tert-butylcalix[4]arene: NMR Study of Interaction and Probable Structures of the Product

Using 1H and 13C NMR spectroscopy, the interaction of tetrapropoxy-p-tert-butyl-calix[4]arene (1) with H3O+ ions produced by hydrogen bis(1,2-dicarbollyl) cobaltate (HDCC) and traces of water was studied in nitrobenzene-d 5. It was shown that 1 readily forms an equimolecular complex with H3O+. The equilibrium constant K of its formation is 2.6 at 296 K. Exchange between bound and free 1 is fast even under mild excess of HDCC, the correlation time τex being about 0.13 ms. NMR shows that H3O+ is bound to the aryl-oxygen atoms and this binding forces the calixarene cup to adopt a more open and symmetrical conformation. This conclusion is in full accord with high precision quantum DFT calculations which find one structure of the complex corresponding to a global energy minimum, in which the H3O+ ion is bound to three of the oxygen atoms by strong hydrogen bonds and to the remaining oxygen by two weaker hydrogen bonds. The calixarene part is forced into a C4 symmetrical opened form. When stored for weeks, the complex gradually transforms into other forms, most probably its hydrates, according to spectral evidence and DFT calculations.