Crystal structure of dichlorobis(1-methylcytosine)cadmium(II)

1979 ◽  
Vol 57 (11) ◽  
pp. 1372-1376 ◽  
Author(s):  
Carole Gagnon ◽  
André L. Beauchamp ◽  
Duc Tranqui

Crystals of CdCl2(1-methylcytosine)2 belong to space group Cc, with a = 10.571(7), b = 24.35(2), c = 7.097(3) Å, β = 57.33(4)°, and Z = 4. The structure was refined over 1988 independent reflections to an R factor of 0.026. The structure consists of monomeric molecules in which cadmium has a (4 + 2)-coordination. Four strong bonds, two Cd—Cl (2.497, 2.485 Å) and two Cd—N(3) (2.281, 2.296 Å), define an approximate tetrahedron around the metal. Two carbonyl oxygens take part in weak Cd—O bonding interactions (2.677, 2.780 Å). The amino groups form only very weak intramolecular hydrogen bonds with chlorine and the difference >30° between angles Cd—N(3)—C(4) and Cd—N(3)—C(2) is ascribed to Cd—O bonding. Similar effects for other metal complexes are discussed in terms of steric hindrance of the amino group and bonding of the carbonyl group.

2011 ◽  
Vol 89 (8) ◽  
pp. 971-977
Author(s):  
Danielle M. Chisholm ◽  
Robert McDonald ◽  
J. Scott McIndoe

Methylation of aromatic amino groups is usually straightforward, but the formation of two intramolecular hydrogen bonds in 3,3′-N,N′-bis(amino)-2,2′-bipyridine and (or) the potential for ring methylation prevents the clean tetramethylation of this molecule. Numerous attempts to make 3,3′-N,N′-bis(dimethylamino)-2,2′-bipyridine produced only complex mixtures of variously methylated products, and the only isolated molecule was 3,3′-N,N′-bis(methylamino)-2,2′-bipyridine, for which an X-ray crystal structure was obtained.


Author(s):  
Takeshi Oishi ◽  
Daichi Yasushima ◽  
Kihiro Yuasa ◽  
Takaaki Sato ◽  
Noritaka Chida

In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation. The C atom at the flap, which is bonded to the hydroxymethyl substituent, deviates from the mean plane of other ring atoms by 0.357 (5) Å. There are two intramolecular hydrogen bonds (O—H...N and N—H...O) between the hydroxy and amino groups, so that O- and N-bound H atoms involved in these hydrogen bonds are each disordered with equal occupancies of 0.50. The methyl 2-methylprop-2-enoate substituent also shows a disordered structure over two sets of sites with refined occupancies of 0.482 (5) and 0.518 (5). In the crystal, molecules are connected into a dimer by an O—H...O hydrogen bond. The dimers are further linked by N—H...O, C—H...N and C—H...O interactions, extending a sheet structure parallel to (\overline{1}01).


IUCrData ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
P. Seethalakshmi ◽  
C. Palanivel

In the title compound, C11H13Cl2NO, the chloroethyl amino groups are twisted with respect to the amino group, with N—C—C—Cl torsion angles of −177.4 (4) and 179.2 (3)°. The carbonyl group lies in the plane of the benzene ring to which it is attached; torsion angles Car—Car—C=O are 0.1 (8) and −178.2 (5)°. In the crystal, C—H...Cl and C—H...O hydrogen bonds link the molecules, forming sheets parallel to (20-1). The sheets are linked by C—H...π interactions, forming a three-dimensional framework.


2020 ◽  
Vol 35 (2) ◽  
pp. 129-135
Author(s):  
James A. Kaduk ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of atazanavir has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Atazanavir crystallizes in space group P21 (#4) with a = 15.33545(7), b = 5.90396(3), c = 21.56949(13) Å, β = 96.2923(4)°, V = 1941.134(11) Å3, and Z = 2. Despite being labeled as “atazanavir sulfate”, the commercial reagent sample consisted of atazanavir free base. The structure consists of an array of extended-conformation molecules parallel to the ac-plane. Although the atazanavir molecule contains only four classical hydrogen bond donors, hydrogen bonding is, surprisingly, important to the crystal energy. Both intra- and intermolecular hydrogen bonds are significant. The hydroxyl group forms bifurcated intramolecular hydrogen bonds to a carbonyl oxygen atom and an amide nitrogen. Several amide nitrogens act as donors to the hydroxyl group and carbonyl oxygen atoms. An amide nitrogen acts as a donor to another amide nitrogen. Several methyl, methylene, methyne, and phenyl hydrogens participate in hydrogen bonds to carbonyl oxygens, an amide nitrogen, and the pyridine nitrogen. The powder pattern is included in the Powder Diffraction File™ as entry 00-065-1426.


2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.


2021 ◽  
pp. 1-9
Author(s):  
James A. Kaduk ◽  
Nicholas C. Boaz ◽  
Emma L. Markun ◽  
Amy M. Gindhart ◽  
Thomas N. Blanton

The crystal structure of osimertinib mesylate Form B has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional techniques. Osimertinib mesylate Form B crystallizes in space group P-1 (#2) with a = 11.42912(17), b = 11.72274(24), c = 13.32213(22) Å, α = 69.0265(5), β = 74.5914(4), γ = 66.4007(4)°, V = 1511.557(12) Å3, and Z = 2. The crystal structure is characterized by alternating layers of cation–anion and parallel stacking interactions parallel to the ab-planes. The cation is protonated at the nitrogen atom of the dimethylamino group, which forms a strong hydrogen bond between the cation and the anion. That hydrogen atom also participates in a weaker intramolecular hydrogen bond to an amino nitrogen. There are two additional N–H⋅⋅⋅O hydrogen bonds between the cation and the anion. Several C–H⋅⋅⋅O hydrogen bonds also link the cations and anions. The powder pattern has been submitted to ICDD® for inclusion in the Powder Diffraction File™.


2012 ◽  
Vol 42 (10) ◽  
pp. 1046-1051 ◽  
Author(s):  
A. S. Dayananda ◽  
Grzegorz Dutkiewicz ◽  
H. S. Yathirajan ◽  
B. Narayana ◽  
Maciej Kubicki

2018 ◽  
Vol 74 (8) ◽  
pp. 1159-1162
Author(s):  
Ramalingam Sangeetha ◽  
Kasthuri Balasubramani ◽  
Kaliyaperumal Thanigaimani ◽  
Savaridasson Jose Kavitha

In the title molecular salt, C9H10N5 +·C7H7O3S−, the asymmetric unit consists of a 2,4-diamino-6-phenyl-1,3,5-triazin-1-ium cation and a 4-methylbenzenesulfonate anion. The cation is protonated at the N atom lying between the amine and phenyl substituents. The protonated N and amino-group N atoms are involved in hydrogen bonding with the sulfonate O atoms through a pair of intermolecular N—H...O hydrogen bonds, giving rise to a hydrogen-bonded cyclic motif with R 2 2(8) graph-set notation. The inversion-related molecules are further linked by four N—H...O intermolecular interactions to produce a complementary DDAA (D = donor, A = acceptor) hydrogen-bonded array, forming R 2 2(8), R 4 2(8) and R 2 2(8) ring motifs. The centrosymmetrically paired cations form R 2 2(8) ring motifs through base-pairing via N—H...N hydrogen bonds. In addition, another R 3 3(10) motif is formed between centrosymetrically paired cations and a sulfonate anion via N—H...O hydrogen bonds. The crystal structure also features weak S=O...π and π–π interactions. Hirshfeld surface and fingerprint plots were employed in order to further study the intermolecular interactions.


2014 ◽  
Vol 70 (12) ◽  
pp. o1292-o1292 ◽  
Author(s):  
Nadir Ghichi ◽  
Ali Benboudiaf ◽  
Hocine Merazig

In the title compound, C20H17NO3, the methylidenecyclohexa-2,4-dienone moiety is approximately planar [maximum deviation = 0.0615 (10) Å] and is oriented at diherdral angles of 69.60 (7) and 1.69 (9)° to the phenyl and hydroxybenzene rings, respectively. The amino group links with the carbonyl O atomviaan intramolecular N—H...O hydrogen bond, forming anS(6) ring motif. In the crystal, the molecules are linked by O—H...O hydrogen bonds and weak C—H...O and C—H...π interactions, forming a three-dimensional supramolecular architecture.


1967 ◽  
Vol 45 (19) ◽  
pp. 2135-2141 ◽  
Author(s):  
P. J. Krueger

The infrared absorption spectra of partially deuterated o-phenylenediamine and 4,5-di-methyl-, 4-methyl-, and 4-chloro-o-phenylenediamine in dilute CCl4 solution show double intramolecular [Formula: see text] hydrogen bonds in which the two NHD groups are equivalent and each group acts as both a proton donor and a proton acceptor. The ring substituent effect on this interaction in these compounds is small. In 4-methoxy-o-phenylenediamine, the amino groups are not equivalent, but double intramolecular hydrogen bonds are still present. In 4-nitro-o-phenylenediamine, only one intramolecular [Formula: see text] hydrogen bond appears to exist. The effect of N-substitution on some of these observations is discussed.


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