scholarly journals Thermodynamically Stable Cationic Dimers in Carboxyl-Functionalized Ionic Liquids: The Paradoxical Case of “Anti-Electrostatic” Hydrogen Bonding

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 366
Author(s):  
Loai Al-Sheakh ◽  
Sebastian Fritsch ◽  
Andreas Appelhagen ◽  
Alexander Villinger ◽  
Ralf Ludwig
Keyword(s):  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Hydrogen Bonds ◽  
Chemical Shifts ◽  
Structural Motif ◽  
Free Energies ◽  
Quantum Cluster ◽  
Repulsive Coulomb ◽  
Repulsive Forces ◽  
Hydrogen Bonded

We show that carboxyl-functionalized ionic liquids (ILs) form doubly hydrogen-bonded cationic dimers (c+=c+) despite the repulsive forces between ions of like charge and competing hydrogen bonds between cation and anion (c+–a−). This structural motif as known for formic acid, the archetype of double hydrogen bridges, is present in the solid state of the IL 1−(carboxymethyl)pyridinium bis(trifluoromethylsulfonyl)imide [HOOC−CH2−py][NTf2]. By means of quantum chemical calculations, we explored different hydrogen-bonded isomers of neutral (HOOC–(CH2)n–py+)2(NTf2−)2, single-charged (HOOC–(CH2)n–py+)2(NTf2−), and double-charged (HOOC– (CH2)n−py+)2 complexes for demonstrating the paradoxical case of “anti-electrostatic” hydrogen bonding (AEHB) between ions of like charge. For the pure doubly hydrogen-bonded cationic dimers (HOOC– (CH2)n−py+)2, we report robust kinetic stability for n = 1–4. At n = 5, hydrogen bonding and dispersion fully compensate for the repulsive Coulomb forces between the cations, allowing for the quantification of the two equivalent hydrogen bonds and dispersion interaction in the order of 58.5 and 11 kJmol−1, respectively. For n = 6–8, we calculated negative free energies for temperatures below 47, 80, and 114 K, respectively. Quantum cluster equilibrium (QCE) theory predicts the equilibria between cationic monomers and dimers by considering the intermolecular interaction between the species, leading to thermodynamic stability at even higher temperatures. We rationalize the H-bond characteristics of the cationic dimers by the natural bond orbital (NBO) approach, emphasizing the strong correlation between NBO-based and spectroscopic descriptors, such as NMR chemical shifts and vibrational frequencies.

Concomitant polymorphs of 1,3-bis(3-fluorophenyl)urea

2016 ◽  
Vol 72 (9) ◽  
pp. 692-696 ◽  
Author(s):  
Christina A. Capacci-Daniel ◽  
Jeffery A. Bertke ◽  
Shoaleh Dehghan ◽  
Rupa Hiremath-Darji ◽  
Jennifer A. Swift
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Engineering ◽  
Structural Motif ◽  
Parallel Orientation ◽  
One Dimensional ◽  
Monoclinic Form ◽  
Engineering Studies ◽  
Hydrogen Bonded

Hydrogen bonding between urea functionalities is a common structural motif employed in crystal-engineering studies. Crystallization of 1,3-bis(3-fluorophenyl)urea, C13H10F2N2O, from many solvents yielded concomitant mixtures of at least two polymorphs. In the monoclinic form, one-dimensional chains of hydrogen-bonded urea molecules align in an antiparallel orientation, as is typical of many diphenylureas. In the orthorhombic form, one-dimensional chains of hydrogen-bonded urea molecules have a parallel orientation rarely observed in symmetrically substituted diphenylureas.

Polymorphs of phenazine hexacyanoferrate(II) hydrate: supramolecular isomerism in a 2D hydrogen-bonded network

2021 ◽  
Vol 77 (2) ◽  
pp. 211-218
Author(s):  
Ivica Cvrtila ◽  
Vladimir Stilinović
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
The Other ◽  
Two Dimensional ◽  
Structural Motifs ◽  
Supramolecular Isomerism ◽  
Other Hand ◽  
Π Stacking ◽  
Hydrogen Bonded

The crystal structures of two polymorphs of a phenazine hexacyanoferrate(II) salt/cocrystal, with the formula (Hphen)3[H2Fe(CN)6][H3Fe(CN)6]·2(phen)·2H2O, are reported. The polymorphs are comprised of (Hphen)2[H2Fe(CN)6] trimers and (Hphen)[(phen)2(H2O)2][H3Fe(CN)6] hexamers connected into two-dimensional (2D) hydrogen-bonded networks through strong hydrogen bonds between the [H2Fe(CN)6]2− and [H3Fe(CN)6]− anions. The layers are further connected by hydrogen bonds, as well as through π–π stacking of phenazine moieties. Aside from the identical 2D hydrogen-bonded networks, the two polymorphs share phenazine stacks comprising both protonated and neutral phenazine molecules. On the other hand, the polymorphs differ in the conformation, placement and orientation of the hydrogen-bonded trimers and hexamers within the hydrogen-bonded networks, which leads to different packing of the hydrogen-bonded layers, as well as to different hydrogen bonding between the layers. Thus, aside from an exceptional number of symmetry-independent units (nine in total), these two polymorphs show how robust structural motifs, such as charge-assisted hydrogen bonding or π-stacking, allow for different arrangements of the supramolecular units, resulting in polymorphism.

scholarly journals The infrared spectra of protic ionic liquids: performances of different computational models to predict hydrogen bonds and conformer evolution

2020 ◽  
Vol 22 (14) ◽  
pp. 7497-7506 ◽  
Author(s):  
O. Palumbo ◽  
A. Cimini ◽  
F. Trequattrini ◽  
J.-B. Brubach ◽  
P. Roy ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Hydrogen Bonds ◽  
Dft Calculations ◽  
Infrared Spectra ◽  
Computational Models ◽  
Far Infrared ◽  
Protic Ionic Liquids ◽  
Far Infrared Spectra

DFT calculations with the ωB97-D functional reproduce hydrogen bonding features of the far-infrared spectra of diethylmethylammonium methanesulfonate and diethylmethylammonium trifluoromethanesulfonate.

Cinnamic acid hydrogen bonds to isoniazid andN′-(propan-2-ylidene)isonicotinohydrazide, anin situreaction product of isoniazid and acetone

2014 ◽  
Vol 70 (4) ◽  
pp. 392-395 ◽  
Author(s):  
Inese Sarcevica ◽  
Liana Orola ◽  
Mikelis V. Veidis ◽  
Sergey Belyakov
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Cinnamic Acid ◽  
Slow Evaporation ◽  
Hydrogen Bonded

A new polymorph of the cinnamic acid–isoniazid cocrystal has been prepared by slow evaporation, namely cinnamic acid–pyridine-4-carbohydrazide (1/1), C9H8O2·C6H7N3O. The crystal structure is characterized by a hydrogen-bonded tetrameric arrangement of two molecules of isoniazid and two of cinnamic acid. Possible modification of the hydrogen bonding was investigated by changing the hydrazide group of isoniazidviaanin situreaction with acetone and cocrystallization with cinnamic acid. In the structure of cinnamic acid–N′-(propan-2-ylidene)isonicotinohydrazide (1/1), C9H8O2·C9H11N3O, carboxylic acid–pyridine O—H...N and hydrazide–hydrazide N—H...O hydrogen bonds are formed.

scholarly journals Hydrogen-bonding patterns in 2-amino-4,6-dimethoxypyrimidine–4-aminobenzoic acid (1/1)

2006 ◽  
Vol 62 (7) ◽  
pp. o2976-o2978 ◽  
Author(s):  
Kaliyaperumal Thanigaimani ◽  
Packianathan Thomas Muthiah ◽  
Daniel E. Lynch
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Carboxyl Group ◽  
Acid Molecule ◽  
Aminobenzoic Acid ◽  
Graph Set ◽  
Supramolecular Chain ◽  
Bonding Patterns ◽  
Hydrogen Bonded

In the title cocrystal, C6H9N3O2·C7H7NO2, the 2-amino-4,6-dimethoxypyrimidine molecule interacts with the carboxyl group of the 4-aminobenzoic acid molecule through N—H...O and O—H...N hydrogen bonds, forming a cyclic hydrogen-bonded motif [R 2 2(8)]. This motif further self-organizes through N—H...O hydrogen bonds to generate an array of six hydrogen bonds with the rings having the graph-set notation R 2 3(6), R 2 2(8), R 4 2(8), R 2 2(8) and R 2 3(6). The 4-aminobenzoic acid molecules self-assemble via N—H...O hydrogen bonds to form a supramolecular chain along the c axis.

Oligosiloxanediols as building blocks for supramolecular chemistry: hydrogen-bonded adducts with amines form supramolecular structures in zero, one and two dimensions

2000 ◽  
Vol 56 (2) ◽  
pp. 273-286 ◽  
Author(s):  
Brian O'Leary ◽  
Trevor R. Spalding ◽  
George Ferguson ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Supramolecular Chemistry ◽  
Building Blocks ◽  
Two Dimensions ◽  
Supramolecular Structures ◽  
Structural Motif ◽  
Two Dimensional ◽  
The Third ◽  
A Chain ◽  
Hydrogen Bonded

The structure of 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol–pyrazine (4/1), (C36H32O4Si3)4·C4H4N2 (1), contains finite centrosymmetric aggregates; the diol units form dimers, by means of O—H...O hydrogen bonds, and pairs of such dimers are linked to the pyrazine by means of O—H...N hydrogen bonds. In 1,1,3,3,5,5-hexaphenyltrisiloxane-1,5-diol–pyridine (2/3), (C36H32O4Si3)2·(C5H5N)3 (2), the diol units are linked into centrosymmetric pairs by means of disordered O—H...O hydrogen bonds: two of the three pyridine molecules are linked to the diol dimer by means of ordered O—H...N hydrogen bonds, while the third pyridine unit, which is disordered across a centre of inversion, links the diol dimers into a C 3 3(9) chain by means of O—H...N and C—H...O hydrogen bonds. In 1,1,3,3-tetraphenyldisiloxane-1,3-diol–hexamethylenetetramine (1/1), (C24H22O3Si2)·C6H12N4 (3), the diol acts as a double donor and the hexamethylenetetramine acts as a double acceptor in ordered O—H...N hydrogen bonds and the structure consists of C 2 2(10) chains of alternating diol and amine units. In 1,1,3,3-tetraphenyldisiloxane-1,3-diol–2,2′-bipyridyl (1/1), C24H22O3Si2·C10H8N2 (4), there are two independent diol molecules, both lying across centres of inversion and therefore both containing linear Si—O—Si groups: each diol acts as a double donor of hydrogen bonds and the unique 2,2′-bipyridyl molecule acts as a double acceptor, thus forming C 2 2(11) chains of alternating diol and amine units. The structural motif in 1,1,3,3-tetraphenyldisiloxane-1,3-diol–pyrazine (2/1), (C24H22O3Si2)2·C4H4N2 (5), is a chain-of-rings: pairs of diol molecules are linked by O—H...O hydrogen bonds into centrosymmetric R 2 2(12) dimers and these dimers are linked into C 2 2(13) chains by means of O—H...N hydrogen bonds to the pyrazine units. 1,1,3,3-Tetraphenyldisiloxane-1,3-diol–pyridine (1/1), C24H22O3Si2·C5H5N (6), and 1,1,3,3-tetraphenyldisiloxane-1,3-diol–pyrimidine (1/1), C24H22O3Si2·C4H4N2 (7), are isomorphous: in each compound the amine unit is disordered across a centre of inversion. The diol molecules form C(6) chains, by means of disordered O—H...O hydrogen bonds, and these chains are linked into two-dimensional nets built from R 6 6(26) rings, by a combination of O—H...N and C—H...O hydrogen bonds.

More examples of the 15-crown-5...H2O—M—OH2...15-crown-5 motif, M = Al3+, Cr3+ and Pd2+

2010 ◽  
Vol 66 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Maxime A. Siegler ◽  
Jacob H. Prewitt ◽  
Steven P. Kelley ◽  
Sean Parkin ◽  
John P. Selegue ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Lattice Water Molecule ◽  
Literature Survey ◽  
The Other ◽  
Water Molecules ◽  
Lattice Water ◽  
Hydrogen Bonding Pattern ◽  
Hydrogen Bonded

Five structures of co-crystals grown from aqueous solutions equimolar in 15-crown-5 (or 15C5) and [M(H2O)6](NO3) n , M = Al3+, Cr3+ and Pd2+, are reported. The hydrogen-bonding patterns in all are similar: metal complexes including the fragment trans-H2O—M—OH2 alternate with 15C5 molecules, to which they are hydrogen bonded, to form stacks. A literature survey shows that this hydrogen-bonding pattern is very common. In each of the two polymorphs of the compound [Al(H2O)6](NO3)3·15C5·4H2O there are two independent cations; one forms hydrogen bonds directly to the 15C5 molecules adjacent in the stack, while the other cation is hydrogen-bonded to two water molecules that act as spacers in the stack. These stacks are then crosslinked by hydrogen bonds formed by the three nitrate counterions and the three lattice water molecules. The hydrogen-bonded stacks in [Cr(H2O)5(NO3)](NO3)2·1.5(15C5)·H2O are discrete rather than infinite; each unit contains two Cr3+ complex cations and three 15C5 molecules. These units are again crosslinked by the uncoordinated nitrate ions and a lattice water molecule. In [Pd(H2O)2(NO3)2]·15C5 the infinite stacks are electrically neutral and are not crosslinked. In [Pd(H2O)2(NO3)2]·2(15C5)·2H2O·2HNO3 a discrete, uncharged unit containing one Pd complex and two 15C5 molecules is `capped off' at either end by a lattice water molecule and an included nitric acid molecule. In all five structures the infinite stacks or discrete units form an array that is at least approximately hexagonal.

scholarly journals Hydrogen bonding in the crystal structure of the molecular salt of pyrazole–pyrazolium picrate

2016 ◽  
Vol 72 (6) ◽  
pp. 861-863 ◽  
Author(s):  
Ping Su ◽  
Xue-gang Song ◽  
Ren-qiang Sun ◽  
Xing-man Xu
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Salt ◽  
Asymmetric Unit ◽  
Molecular Salt ◽  
Hydrogen Bonded

The asymmetric unit of the title organic salt [systematic name: 1H-pyrazol-2-ium 2,4,6-trinitrophenolate–1H-pyrazole (1/1)], H(C3H4N2)2+·C6H2N3O7−, consists of one picrate anion and one hydrogen-bonded dimer of a pyrazolium monocation. The H atom involved in the dimer N—H...N hydrogen bond is disordered over both symmetry-unique pyrazole molecules with occupancies of 0.52 (5) and 0.48 (5). In the crystal, the component ions are linked into chains along [100] by two different bifurcated N—H...(O,O) hydrogen bonds. In addition, weak C—H...O hydrogen bonds link inversion-related chains, forming columns along [100].

Strategies for Crystal Engineering of Polar Solids

1993 ◽  
Vol 328 ◽  
Author(s):  
Mike Zaworotko ◽  
S. Subramanian ◽  
L. R. Macgillivray
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Engineering ◽  
Organic Cation ◽  
Polar Materials ◽  
Structural Analogues ◽  
Cubane Cluster ◽  
Self Assembled ◽  
Hydrogen Bonded

ABSTRACTCrystal engineering has been invoked to design structural analogues of two prototypal SHG active solids, p-nitroaniline (pNA) and potassium dihydrogenphosphate (KDP). pNA exists as linear polar strands because of head-to-tail hydrogen bonding between adjacent molecules whereas KDP is a self-assembled hydrogen bonded diamondoid network that becomes polar when the hydrogen bonds align. We detail preparation and crystallographic characterization of two classes of multicomponent solid, organic cation hydrogen sulfates and cocrystals of the cubane cluster [M (CO)3(μ3-OH)]4, which structurally mimic pNA and KDP, respectively. Several of the Multi-component solids are polar and they represent a generic approach to designing new polar materials since one component can be changed without altering the basic architecture within the crystal.

Sign in / Sign up

Export Citation Format

Share Document