Intramolecular hydrogen-bonding in carbohydrate crystal-structures

1973 ◽  
Vol 28 (2) ◽  
pp. 233-241 ◽  
Author(s):  
George A. Jeffrey
2015 ◽  
Vol 71 (9) ◽  
pp. 768-775
Author(s):  
Hendrik Klien ◽  
Wilhelm Seichter ◽  
Konstantinos Skobridis ◽  
Edwin Weber

Having reference to an elongated structural modification of 2,2′-bis(hydroxydiphenylmethyl)biphenyl, (I), the two 1,1′:4′,1′′-terphenyl-based diol hosts 2,2′′-bis(hydroxydiphenylmethyl)-1,1′:4′,1′′-terphenyl, C44H34O2, (II), and 2,2′′-bis[hydroxybis(4-methylphenyl)methyl]-1,1′:4′,1′′-terphenyl, C48H42O2, (III), have been synthesized and studied with regard to their crystal structures involving different inclusions,i.e.(II) with dimethylformamide (DMF), C44H34O2·C2H6NO, denoted (IIa), (III) with DMF, C48H42O2·C2H6NO, denoted (IIIa), and (III) with acetonitrile, C48H42O2·CH3CN, denoted (IIIb). In the solvent-free crystals of (II) and (III), the hydroxy H atoms are involved in intramolecular O—H...π hydrogen bonding, with the central arene ring of the terphenyl unit acting as an acceptor. The corresponding crystal structures are stabilized by intermolecular C—H...π contacts. Due to the distinctive acceptor character of the included DMF solvent species in the crystal structures of (IIa) and (IIIa), the guest molecule is coordinated to the hostviaO—H...O=C hydrogen bonding. In both crystal structures, infinite strands composed of alternating host and guest molecules represent the basic supramolecular aggregates. Within a given strand, the O atom of the solvent molecule acts as a bifurcated acceptor. Similar to the solvent-free cases, the hydroxy H atoms in inclusion structure (IIIb) are involved in intramolecular hydrogen bonding, and there is thus a lack of host–guest interaction. As a result, the solvent molecules are accommodated as C—H...N hydrogen-bonded inversion-symmetric dimers in the channel-like voids of the host lattice.


2002 ◽  
Vol 2 (6) ◽  
pp. 653-664 ◽  
Author(s):  
Paul W. Baures ◽  
Jeremy R. Rush ◽  
Alexander V. Wiznycia ◽  
John Desper ◽  
Brian A. Helfrich ◽  
...  

1981 ◽  
Vol 59 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Michael L. Post ◽  
Carol P. Huber ◽  
George I. Birnbaum ◽  
David Shugar

The structures of 1-α-D-xylofuranosylcytosine, C9H13N3O5 (1), and its hydrochloride salt, C9H13N3O5•HCl (1•HCl), have been determined by X-ray diffraction from diffractometer data, using direct method techniques. Both compounds crystallize in the orthorhombic system with Z = 4. Space group and cell parameters are, for 1: P21212, a = 18.706, b = 8.127, c = 7.007 Å; and for 1 HCl::P21212, a = 16.800, b = 8.045, c = 8.897 Å. Refinement by block-diagonal least-squares calculations gave a final R of 0.033 on 873 reflections and 0.034 on 914 reflections for 1 and 1 HCl, respectively. The glycosyl torsion angles are in the anti domain, χCN = −25.1° (1) and −28.6° (1•HC1), and the sugar puckers are nearly pure [Formula: see text] and 3E (1•HCl) forms. The C(4′)—C(5′) rotamer is trans–gauche in both cases. No intramolecular hydrogen bonding occurs in the xylofuranosyl rings. Lattice packing in the crystal structures occurs via intermolecular hydrogen bonding, with base stacking in pairs about one of the 2-fold axes for the neutral form, and with no base-stacking interactions for the protonated form. The biological implications of the structure and conformation of α-nucleosides are examined.


2019 ◽  
Vol 7 (42) ◽  
pp. 13104-13110 ◽  
Author(s):  
Jayabalan Pandidurai ◽  
Jayachandran Jayakumar ◽  
Natarajan Senthilkumar ◽  
Chien-Hong Cheng

The crystal structures show a U shape for 26DAcBPy and 26DPXZBPy and a linear chain conformation for 25DAcBPy; for the first time, we reveal that the conformations are the result of intramolecular hydrogen bonding of these molecules.


2016 ◽  
Vol 72 (8) ◽  
pp. 1201-1205
Author(s):  
Sheri Lense ◽  
Nicholas A. Piro ◽  
Scott W. Kassel ◽  
Andrew Wildish ◽  
Brent Jeffery

The structures of two facially coordinated Group VII metal complexes,fac-[ReCl(C10H8N2O2)(CO)3]·C4H8O (I·THF) andfac-[MnBr(C10H8N2O2)(CO)3]·C4H8O (II·THF), are reported. In both complexes, the metal ion is coordinated by three carbonyl ligands, a halide ligand, and a 6,6′-dihydroxy-2,2′-bipyridine ligand in a distorted octahedral geometry. Both complexes co-crystallize with a non-coordinating tetrahydrofuran (THF) solvent molecule and exhibit intermolecular but not intramolecular hydrogen bonding. In both crystal structures, chains of complexes are formed due to intermolecular hydrogen bonding between a hydroxy group from the 6,6′-dihydroxy-2,2′-bipyridine ligand and the halide ligand from a neighboring complex. The THF molecule is hydrogen bonded to the remaining hydroxy group.


Author(s):  
Ligia R. Gomes ◽  
John Nicolson Low ◽  
Fernando Cagide ◽  
Fernanda Borges

FourN-(4-halophenyl)-4-oxo-4H-chromene-3-carboxamides (halo = F, Cl, Br and I),N-(4-fluorophenyl)-4-oxo-4H-chromene-3-carboxamide, C16H10FNO3,N-(4-chlorophenyl)-4-oxo-4H-chromene-3-carboxamide, C16H10ClNO3,N-(4-bromophenyl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3,N-(4-iodophenyl)-4-oxo-4H-chromene-3-carboxamide, C16H10INO3, have been structurally characterized. The molecules are essentially planar and each exhibits ananticonformation with respect to the C—N rotamer of the amide and acisgeometry with respect to the relative positions of the Carom—Carombond of the chromone ring and the carbonyl group of the amide. The structures each exhibit an intramolecular hydrogen-bonding network comprising an N—H...O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming anS(6) ring, and a weak Carom—H...O interaction with the O atom of the carbonyl group of the amide as acceptor, which forms anotherS(6) ring. All four compounds have the same supramolecular structure, consisting ofR22(13) rings that are propagated along thea-axis direction by unit translation. There is π–π stacking involving inversion-related molecules in each structure.


2000 ◽  
Vol 56 (6) ◽  
pp. 1046-1053 ◽  
Author(s):  
Greig Chisholm ◽  
Alan R. Kennedy ◽  
Sharon Wilson ◽  
Simon J. Teat

The structures of three methyl-substituted acetoacetanilides and of an azo pigment derived from one of them are presented and discussed together with a review of related known crystal structures. By considering the position of any aromatic substituents it is possible to predict whether the simple acetoacetanilides adopt planar structures with intramolecular hydrogen bonding or twisted structures featuring intermolecular hydrogen bonding. However, we find that the same crystal engineering rules cannot be applied to the related azo pigments: this is apparently due to the presence of an sp 2 atom which facilitates the adoption of planar conformations. The thermal properties of the acetoacetanilides were measured by DSC and are discussed with reference to their crystal structures.


10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai

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