Stabilization of a Host-Guest Type Complex by Bifurcated Hydrogen Bonds : 18-crown-6 · (2,4-Dinitrophenylhydrazine)2a

1981 ◽  
Vol 36 (2) ◽  
pp. 242-247 ◽  
Author(s):  
R. Hilgenfeld ◽  
W. Saenger

Abstract The X-ray structure of the 1:2 host-guest complex between 1,4,7,10,13,16-hexaoxa-cyclooctadecane (18-crown-6) and 2,4-dinitrophenylhydrazine is reported. Crystallo-graphy data are: space group P21/c, a = 8.557(2), b = 16.745(6), c = 12.387(4) Å, β = 117.08(13)°, Z = 2, Dm = 1.37 g · cm-3 , Dc = 1.387 g · cm-3 , m.p. 414 K (decomp.). The present B is 0.11 for 1733 diffractometer data. In the complex, the two 2,4-dinitrophenylhydrazine molecules are located "above" and "below" the plane of the hexaether and related by an inversion centre. They interact with the macrocyclic host via N-H···0 hydrogen bonds, two of which are bifurcated. All the ether oxygens of the crown serve as hydrogen bond acceptors.

2000 ◽  
Vol 53 (6) ◽  
pp. 451 ◽  
Author(s):  
Murray S. Davies ◽  
Ronald R. Fenton ◽  
Fazlul Huq ◽  
Edwina C. H. Ling ◽  
Trevor W. Hambley

Two complexes, namely, chloro[N-(2-aminoethyl)-N-(2-ammonioethyl)ethane-1,2-diamine]platinum(II) chloride {[PtCl(tren+H)]Cl2} and dichloro[4,7-diaza-1-azoniacyclononane]platinum(II) tetrachloroplatinate(II)–water (1/2) {[PtCl2(tacn+H)]2[PtCl4]·2H2O}, have been prepared and structurally characterized by single-crystal X-ray diffractometry as part of a study of the nature and strength of Pt···H(–N) interactions. Crystals of [PtCl(tren+H)]Cl2 are monoclinic, space group P21/c, a 8.293(2), b 14.396(6), c 11.305(3) Å, β 107.34(2)º, Z 4, and the structure has been refined to a residual of 0.042 based on 1631 reflections. Crystals of [PtCl2(tacn+H)]2[PtCl4]·2H2O are monoclinic, space group P21/a, a 12.834(4), b 8.206(4), c 13.116(8) Å, β 93.01(4)˚, Z 2, and the structure has been refined to a residual of 0.035 based on 1974 reflections. In [PtCl(tren+H)]2+, the protonated amine forms hydrogen bonds with chloride anions and no close contacts with the metal ion. In [PtCl2(tacn+H)]+, a short intramolecular contact is observed between the metal and the protonated amine and the results of molecular mechanics modelling are consistent with there being a Pt···H hydrogen bond. Molecular mechanics modelling of [PtCl(tren+H)]2+ and [PtCl2(dien+H)]+ shows that the protonated amines could readily form close contacts with the metal. It is concluded that there is evidence for the formation of Pt···H(–N) hydrogen bonds but these bonds are very weak, being similar or lower in energy than Cl···H(–NPt) hydrogen bonds.


2010 ◽  
Vol 65 (4) ◽  
pp. 479-484 ◽  
Author(s):  
Guido J. Reiß ◽  
Michaela K. Meyer

Diisopropylammonium trifluoroacetate ({[iPr2NH2][CF3COO]}; dip tfa; 1) and diisopropylammonium pentafluoropropionate ({[iPr2NH2][C2F5COO]}; dip pfp; 2) have been synthesized and structurally characterized by X-ray diffraction and spectroscopic methods. Both compounds form hydrogen-bonded cyclic dimers (Etter symbol: R44 (12)) in the solid state. The asymmetric unit of 1 contains one trifluoroacetate anion and one dip cation in the centrosymmetric space group Pī. The asymmetric unit of 2 consists of two crystallographically independent pentafluoropropionate anions and two independent dip cations forming dimers in the form of rings, both lying around centers of symmetry in the space group Pī. In dip tfa and dip pfp the cations act as double hydrogen bond donors, and each of the two oxygen atoms of the carboxyl group are single hydrogen bond acceptors. The donor acceptor distances of the N-H...O hydrogen bonds are within the expected range for medium strong hydrogen bonds. The quasi-molecular cyclic dimers are connected with neighboring units only by van der Waals interactions.


1999 ◽  
Vol 54 (5) ◽  
pp. 643-648 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones

The compounds (2-pyridone)2H+(MeSO2)2N- (1, monoclinic, space group P21/n ) and (6- methyl-2-pyridone)2H+(MeSO2)2N- (2, triclinic, P1) crystallize selectively and in good yields when the parent 2-pyridones (2-hydroxypyridines) are treated with the strong NH acid dimesylamine in acetonitrile or acetone. The corresponding 2-hydroxypyridinium salts could not be obtained. In the unprecedented crystal structures of 1 and 2, two pyridone units are linked by a proton to form very short and approximately symmetric O⋯H+ ⋯O hydrogen bonds, the adjacent C-O distances being appreciably elongated as compared to “free” pyridones [1: O ⋯ O 241.8(2), C -O 127.8(3) and 129.1(2) pm; 2: O ⋯ O 243.8(2), C -O 128.1(2) and 129.2(2) pm]. In both crystal packings, the homoconjugate cations and the dimesylamide anions are alternately associated into chains by an N - H ⋯ N “ and an N - H ⋯ O hydrogen bond.


2013 ◽  
Vol 68 (3) ◽  
pp. 214-222 ◽  
Author(s):  
Jörg Hübscher ◽  
Michael Günthel ◽  
Robert Rosin ◽  
Wilhelm Seichter ◽  
Florian Mertens ◽  
...  

Two new linker-type molecules 1a and 1b composed of o-hydroxyacetophenone coordinative groups attached to linear ethynylene or 1,4-phenylenediethynylene spacer units have been synthesised and structurally characterised. An X-ray crystallographic study for both compounds has shown structures with strong intramolecular hydrogen bonds fitting in the model of ‘Intramolecular Resonance Assisted Hydrogen Bond (IRHAB)’. Initial coordination experiments with Cu(II) were performed and the resulting materials characterised by PXRD. The similarity of the copper coordination between these compounds and copper(II) acetylacetonate complexes was demonstrated by XPS measurements. Based on the evidence of these studies, and on elemental analysis, the formation of the corresponding coordination polymers comprising Cu(II) and the linkers has been proposed


2001 ◽  
Vol 58 (1) ◽  
pp. 94-108 ◽  
Author(s):  
Craig J. Kelly ◽  
Janet M. S. Skakle ◽  
James L. Wardell ◽  
Solange M. S. V. Wardell ◽  
John N. Low ◽  
...  

Molecules of N-(4′-iodophenylsulfonyl)-4-nitroaniline, 4-O2NC6H4NHSO2C6H4I-4′ (1), are linked by three-centre I...O2N interactions into chains and these chains are linked into a three-dimensional framework by C—H...O hydrogen bonds. In the isomeric N-(4′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4NHSO2C6H4NO2-4′ (2), the chains generated by the I...O2N interactions are again linked into a three-dimensional framework by C—H...O hydrogen bonds. Molecules of N,N-bis(3′-nitrophenylsulfonyl)-4-iodoaniline, 4-IC6H4N(SO2C6H4NO2-3′)2 (3), lie across twofold rotation axes in space group C2/c and they are linked into chains by paired I...O=S interactions: these chains are linked into sheets by a C—H...O hydrogen bond, and the sheets are linked into a three-dimensional framework by aromatic π...π stacking interactions. In N-(4′-iodophenylsulfonyl)-3-nitroaniline, 3-O2NC6H4NHSO2C6H4I-4′ (4), there are R^2_2(8) rings formed by hard N—H...O=S hydrogen bonds and R^2_2(24) rings formed by two-centre I...nitro interactions, which together generate a chain of fused rings: the combination of a C—H...O hydrogen bond and aromatic π...π stacking interactions links the chains into sheets. Molecules of N-(4′-iodophenylsulfonyl)-4-methyl-2-nitroaniline, 4-CH3-2-O2NC6H3NHSO2C6H4I-4′ (5), are linked by N—H...O=S and C—H...O(nitro) hydrogen bonds into a chain containing alternating R^2_2(8) and R^2_2(10) rings, but there are no I...O interactions of either type. There are two molecules in the asymmetric unit of N-(4′-iodophenylsulfonyl)-2-nitroaniline, 2-O2NC6H4NHSO2C6H4I-4′ (6), and the combination of an I...O=S interaction and a hard N—H...O(nitro) hydrogen bond links the two types of molecule to form a cyclic, centrosymmetric four-component aggregate. C—H...O hydrogen bonds link these four-molecule aggregates to form a molecular ladder. Comparisons are made with structures retrieved from the Cambridge Structural Database.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


2018 ◽  
Vol 74 (4) ◽  
pp. 406-410 ◽  
Author(s):  
Mark Strey ◽  
Peter G. Jones

During our studies of urea and thiourea adducts, we noticed that no adducts with unsubstituted pyridine had been structurally investigated. The 1:1 adduct of pyridine and urea, C5H5N·CH4N2O, crystallizes in the P21/c space group with Z = 4. The structure is of a standard type for urea adducts, whereby the urea molecules form a ribbon, parallel to the a axis, consisting of linked R 2 2(8) rings, and the pyridine molecules are attached to the periphery of the ribbon by bifurcated (N—H...)2N hydrogen bonds. The 1:1 adduct of pyridine and thiourea, C5H5N·CH4N2S, crystallizes in the P21/n space group, with Z = 32 (Z′ = 8). The structure displays similar ribbons to those of the urea adduct. There are two independent ribbons parallel to the b axis at z ≃ 0 and 1 \over 2, and three at z ≃ 1 \over 4 and 3 \over 4; the latter are crosslinked to form a layer structure by additional long N—H...S interactions, which each formally replace one branch of a bifurcated hydrogen-bond system.


1996 ◽  
Vol 52 (2) ◽  
pp. 323-327 ◽  
Author(s):  
A. Hirano ◽  
Y. Kubozono ◽  
H. Maeda ◽  
H. Ishida ◽  
S. Kashino

For crystals of ammonium hydrogen succinate it is known that the space group is P{\bar 1} with Z = 2 at 293 K and the second-order phase transition occurs around 170 K. X-ray crystal structure analyses above and below 170 K have been carried out in order to study the change in mode of short hydrogen bonds between the hydrogen succinate ions. The space group was determined to be P{\bar 1} at 150 and 190 K by structure analysis. No ordering of the H-atom positions in the short hydrogen bonds occurs by the phase transition. The hydrogen bonds show a decrease in the O...O distances with a decrease in temperature from 290 to 190 K, but no significant change in the geometries between 190 and 150 K. Disorder of the NH4 + ion is not observed at 297, 190 and 150 K. Significant change through the phase transition is found only in the geometry of one of the N—H...O hydrogen bonds between ammonium and hydrogen succinate ions.


Author(s):  
Rosita Diana ◽  
Angela Tuzi ◽  
Barbara Panunzi ◽  
Antonio Carella ◽  
Ugo Caruso

The title benzofuran derivatives 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF1), C19H18N2O6, and 2-methoxyethyl 2-amino-5-hydroxy-4-(4-nitrophenyl)benzofuran-3-carboxylate (BF2), C18H16N2O7, recently attracted attention because of their promising antitumoral activity. BF1 crystallizes in the space group P\overline{1}. BF2 in the space group P21/c. The nitrophenyl group is inclined to benzofuran moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the molecular structures of BF1 and BF2 is the intramolecular N—H...Ocarbonyl hydrogen bond. In the crystal of BF1, the molecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of molecules along the b-axis direction are linked by O—H...Omethoxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).


2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.


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