The Hexakis(N,N'-Dimethylurea)Cobalt(Ii) Cation: A Flexible Building Block for the Construction of Hydrogen Bonded Networks

2003 ◽  
Vol 58 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Giannis S. Papaefstathiou ◽  
Robby Keuleers ◽  
Constantinos J. Milios ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
...  

AbstractThe ligand N.N'-dimethylurea (DMU) is used to propagate the octahedral coordination geom- etry of [Co(DMU)6]2+ into 1D and 2D assemblies via a combination of coordinative bonds and interionic hydrogen-bonding. Compounds [Co(DMU)6](ClO4)2 (1), [Co(DMU)6](BF4)2 (2) and [Co(DMU)6](NO3)2 (3) have been prepared from the reactions of DMU and the appropriate hydrated cobalt(II) salts in EtOH. MeCN or Me2CO (only for 1) in the presence of 2,2-di- methoxypropane. Crystal structure determinations demonstrate the existence of [Co(DMU)6]2+ cations and CIO4- , BF4- or NO3- counterions. The great stability of the [Co(DMU)6]2+ cation in the solid state is attributed to a pseudochelate effect which arises from the existence of strong intracationic N-H···O(DMU) hydrogen bonds. The [Co(DMU)6]2+ cations and counterions self- assemble to form a hydrogen-bonded ID architecture in 1, and different 2D hydrogen-bonded networks in 2 and 3. The precise nature of the resulting supramolecular structure is influenced by the nature of the counterion. Two main motifs of intermolecular (interionic) hydrogen bonds have been observed: N-H ···O(ClO4-, NO3-) or N-H ··· F(BF4-) and weak C-H F(BF4- ) or C-H-O(NO3- ) hydrogen bonds. The complexes were also characterized by vibrational spec- troscopy (IR, far-IR. low-frequency Raman). The spectroscopic data are discussed in terms of the nature of bonding and the know;n structures.

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Labrini Drakopoulou ◽  
Catherine P. Raptopoulou ◽  
Aris Terzis ◽  
Giannis S. Papaefstathiou

N,N'-diethylurea (DEU) was employed as a ligand to form the octahedral complexes[M(DEU)6]2+(M=Co, Ni and Zn). Compounds[Co(DEU)6](BF4)2(1),[Co(DEU)6](CIO4)2(2),[Ni(DEU)6](CIO4)2(3), and[Zn(DMU)6](CIO4)2(4) have been prepared from the reactions of DEU and the appropriate hydrated metal(II) salts in EtOH in the presence of 2,2-dimethoxypropane. Crystal structure determinations demonstrate the existence of[M(DEU)6]2+cations andCIO4-(in2–4) orBF4-(in1) counterions. The[M(DEU)6]2+cations in the solid state are stabilized by apseudochelateeffect due to the existence of six strong intracationicN-H⋯O(DEU)hydrogen bonds. The[M(DEU)6]2+cations and counterions self-assemble to form hydrogen-bonded 2D architectures in2–4that conform to thekgd(kagome dual) network, and a 3D hydrogen-bondedrtl(rutile) network in1. The nature of the resulting supramolecular structures is influenced by the nature of the counter-ion. The complexes were also characterized by vibrational spectroscopy (IR).


1988 ◽  
Vol 41 (4) ◽  
pp. 419 ◽  
Author(s):  
AD Rae ◽  
CG Ramsay ◽  
PJ Steel

The title compounds are shown to exist in solution and in the solid state as 4H-tautomers. X-Ray crystal structure determinations show that 1,3-diphenyl-1,2,4-triazol-5-one exists as a dimeric pair of strongly hydrogen-bonded molecules and that 3-phenyl-1-(2-pyridyl)-1,2,4- triazol-5-one exists as the 4H-tautomer stabilized by a complex network of hydrogen bonding to water molecules.


2014 ◽  
Vol 70 (4) ◽  
pp. 392-395 ◽  
Author(s):  
Inese Sarcevica ◽  
Liana Orola ◽  
Mikelis V. Veidis ◽  
Sergey Belyakov

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.


Author(s):  
Ping Su ◽  
Xue-gang Song ◽  
Ren-qiang Sun ◽  
Xing-man Xu

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].


1999 ◽  
Vol 54 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Christian Hollatz ◽  
Annette Schier ◽  
Hubert Schmidbaur

Diphenyl(2-hydroxy-phenyl)phosphine was introduced as a ligand for gold(I) halides and pentafluorophenyl gold(I) in order to probe the interplay of intra- and intermolecular interactions based on aurophilic (Au· · ·Au) and hydrogen bonding. 1:1 complexes of the type Ph2(2-HO-C6H4)P-Au-X with X = Cl, Br, C6F5 have been prepared and characterized by analytical and spectroscopic data. The crystal structure of the chloro complex (1) has been determined. In the lattice the molecules form dimers through O-H· · ·Cl hydrogen bonds. Au· · ·Au contacts are ruled out by steric congestion. Reaction of 1 with triethylamine yields a 1:1 adduct with O-H· · ·NEt3 hydrogen bonding. The trimethylsilyl ether of the title ligand also forms 1:1 complexes with AuCl, AuBr, Aul, and AuC6F5. The crystal structures of the chloro (5) and iodo (7) compound have been determined. In both cases the lattices are built from monomers which show only minor differences in their conformations. The silylether groups are not acting as intra- or intermolecular donor functions to the gold atoms.


Author(s):  
Eric Bosch ◽  
Nathan P. Bowling ◽  
Shalisa M. Oburn

We report the design, synthesis, and crystal structure of a conjugated aryleneethynyl molecule, 2-(2-{4,5-dimethoxy-2-[2-(2,3,4-trifluorophenyl)ethynyl]phenyl}ethynyl)-6-[2-(pyridin-2-yl)ethynyl]pyridine, C30H17F3N2O2, that adopts a planar rhombus conformation in the solid state. The molecule crystallizes in the space group P\overline{1}, with Z = 2, and features two intramolecular sp2 -C—H...N hydrogen bonds that co-operatively hold the arylethynyl molecule in a rhombus conformation. The H atoms are activated towards hydrogen bonding since they are situated on a trifluorophenyl ring and the H...N distances are 2.470 (16) and 2.646 (16) Å, with C—H...N angles of 161.7 (2) and 164.7 (2)°, respectively. Molecular electrostatic potential calculations support the formation of C—H...N hydrogen bonds to the trifluorophenyl moiety. Hirshfeld surface analysis identifies a self-complementary C—H...O dimeric interaction between adjacent 1,2-dimethoxybenzene segments that is shown to be common in structures containing that moiety.


Author(s):  
Kostiantyn V. Domasevitch ◽  
Ganna A. Senchyk ◽  
Andrey B. Lysenko ◽  
Eduard B. Rusanov

The structure of the title salt, ammonium carbamoylcyanonitrosomethanide, NH4 +·C3H2N3O2 −, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The nitroso O-atoms accept as many as three N—H...O bonds from the ammonium cations [N...O = 2.688 (3)–3.000 (3) Å] to form chains of fused rhombs [(NH4)(O)2]. The most prominent bonds of the carbamoyl groups are mutual and they yield 21 helices [N...O = 2.903 (2) Å], whereas the cyano N-atoms accept hydrogen bonds from sterically less accessible carbamoyl H-atoms [N...N = 3.004 (3) Å]. Two weaker NH4 +...O=C bonds [N...O = 3.021 (2), 3.017 (2) Å] complete the hydrogen-bonded environment of the carbamoyl groups. A Hirshfeld surface analysis indicates that the most important interactions are overwhelmingly O...H/H...O and N...H/H...N, in total accounting for 64.1% of the contacts for the individual anions. The relatively simple scheme of these interactions allows the delineation of the supramolecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions.


2000 ◽  
Vol 65 (10) ◽  
pp. 1587-1596 ◽  
Author(s):  
Jaroslav Podlaha ◽  
Ivana Císařová ◽  
Daniel Alexander ◽  
Petr Holý ◽  
Tomáš Kraus ◽  
...  

Solid-state self-assembly of 2,4,6-trimethylbenzene-1,3,5-tris(methanaminium) 2,4,6-trimethylbenzene-1,3,5-triacetate is mediated by hydrogen bonding. It gives rise to three-dimensional network of hydrogen bonds in which each trication is coordinated with eight trianions and vice versa. The resulting crystal structure topologically corresponds to the simple inorganic cesium chloride type.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1826-C1826
Author(s):  
Prof. Emmanuel Marfo-Owusu ◽  
Dr. Amber Thompson

The crystal structure of 1:1:1 complex of chloranilic acid with benzimidazole and water determined by X-ray diffraction methods is reported. It crystallizes in the monoclinic (space group, P21/c) crystal system. Both chloranilic acid and benzimidazole molecules adopt a face-to-face stacking arrangement along the b-axis. An interaction beween adjacent layers is a π...π stacking interactions between chloranilic acid molecules. The dihedral angle between the interacting chloranilic acid ring planes is only 1.22 (7)0with an interplanar spacing between C10...C12 (3.383 (16) Å) and C13...C15 (3.351 (14) Å ). Water influences proton transfer in the hydrogen bonded charge transfer complex, and contributes to generating increased number of hydrogen bonds utilized in the stabilzaation of the crystal structure of the complex. Water serves as an efficient bridge between the chloranilic acid molecules through O-H...O intermolecular hydrogen bonds to form a zigzag channel, as well as directly linking chloranilic acid molecules with benzimidazole molecules which are strongly entrapped within the zigzag channel by intermolecular hydrogen bonding network involving the N-H...O, C-H...O, and C-H...Cl interactions. In the chloranilate anion structure, an intramolecular hydrogen bonding involving O2-H7 and O1 (dO2... O1 and dH7... O1 = 2.670 (12) and 2.25 Å) occurs. The supramolecular architecture of the hydrogen bonded charge complex exhibits a three-dimensional hydrogen bonding network


Meso erythritol forms a tetragonal structure in which the molecules are centro-symmetric. Each α -hydroxyl group forms part of a tetragonal spiral of hydrogen bonds. These spirals alone are sufficient to link all the molecules of the crystal into a three-dimensional hydrogen-bonded complex. The β -hydroxyl groups of neighbouring molecules form closed circuits of four hydrogen bonds in a tetrahedron so flattened as to be almost a square. These closed circuits are also by themselves sufficient to link all molecules in the crystal into a three-dimensional complex. When some of the hydroxyl groups are replaced by fluorine atoms of approximately the same size, the main structure should be retained if sufficient hydrogen bonding is left. It is possible, therefore, to predict structures for meso , d , l and racemic forms of some of the fluoro-substituted derivatives. 2-deoxy-2-fluoro (±) erythritol has been examined and found to have the expected racemic structure. The possibility of forms transitional between dextro , racemic, and laevo , is discussed.


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