Methyl Groups as Hydrogen Bond Acceptors via Their sp3 Carbon Atoms

2021 ◽  
Author(s):  
Oliver Loveday ◽  
Jorge Echeverría
Keyword(s):  
Hydrogen Bond ◽  
Methyl Groups

scholarly journals (E)-N-{3-[(m-Tolylimino)methyl]pyridin-2-yl}pivalamide

IUCrData ◽  
2017 ◽  
Vol 2 (11) ◽  
Author(s):  
Şehriman Atalay ◽  
Semra Gerçeker ◽  
Seher Meral
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Torsion Angle ◽  
Title Compound ◽  
Methyl Groups ◽  
Compound C ◽  
Benzene Rings

In the title compound, C18H21N3O, the dihedral angle between the pyridine and benzene rings is 30.53 (7)° and the C—C=N—C torsion angle is −170.6 (2)°. An intramolecular N—H...N hydrogen bond generates anS(6) ring. In the crystal, very weak C—H...O hydrogen bonds link the molecules intoC(8) [101] chains. Thetert-butyl methyl groups are disordered over two sets of sites in a 0.783 (4):0.217 (4) ratio.

The Role of Methyl Groups in the Formation of Hydrogen Bond in DMSO−Methanol Mixtures

2006 ◽  
Vol 128 (5) ◽  
pp. 1438-1439 ◽  
Author(s):  
Qingzhong Li ◽  
Guoshi Wu ◽  
Zhiwu Yu
Keyword(s):  
Hydrogen Bond ◽  
Methyl Groups

scholarly journals 3-Acetyl-1-(3-methylphenyl)thiourea

2012 ◽  
Vol 68 (8) ◽  
pp. o2574-o2574 ◽  
Author(s):  
B. Thimme Gowda ◽  
Sabine Foro ◽  
Sharatha Kumar
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Benzene Ring ◽  
Title Compound ◽  
Side Chain ◽  
Maximum Deviation ◽  
Methyl Groups ◽  
Compound C ◽  
Ring Motif

In the crystal structure of the title compound, C10H12N2OS, the conformation of the two N—H bonds areantito each other. The amide C=O and the C=S are are alsoantito each other. The N—H bond adjacent to the benzene ring issynto them-methyl groups. The dihedral angle between the benzene ring and the side chain [mean plane of atoms C—C(O)N—C—N; maximum deviation 0.029 (2) Å] is 14.30 (7)°. There is an intramolecular N—H...O hydrogen bond generating anS(6) ring motif. In the crystal, the molecules are linkedviaN—H...) hydrogen bonds, forming chains propagating along [001]. The S atom is disordered and was refined using a split model [occupancy ratio 0.56 (4):0.44 (4)].

Article

1998 ◽  
Vol 76 (3) ◽  
pp. 301-306
Author(s):  
Sengen Sun ◽  
James F Britten ◽  
Christopher N Cow ◽  
Chérif F Matta ◽  
Paul HM Harrison
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
The Other ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
Form Part ◽  
Two Sides ◽  
Opposite Helicity

The crystal structure of 3,4,7,8-tetramethylglycoluril (5) was determined by X-ray diffraction. The structure reveals a hydrogen-bonding motif in the crystal lattice that differs from that present in related glycolurils. The two sides of each molecule form part of two independent, but parallel, infinite helical chains. These chains are formed by the NH donor and C==O acceptor on one side of a glycoluril molecule, forming H-bonds to two different molecules at adjacent positions within the helix. On the other side of the same molecule, a similar motif generates another helix of opposite helicity to the first. The molecule has a crystallographic plane of symmetry through the two bridgehead carbon atoms and the two bridgehead methyl groups, which are syn-periplanar. Thus, 5 is similar to 3,4-dimethylglycoluril (3), but differs from some glycolurils, where there is a significant dihedral angle between the two bridgehead-to-bridgehead substituent bonds. Bond lengths and angles in 5 resemble those reported for 3, but bond lengths around the bridgehead positions are slightly lengthened relative to 3.Key words: glycoluril, 1,2,5,8-tetramethyl-2,6,7,8-tetraazabicyclo[3.3.0]octane-3,7-dione, X-ray diffraction, crystal structure, hydrogen-bond array.

Cross Linking of Collagen by Hydrophobe Bonds

1971 ◽  
Vol 15 ◽  
pp. 527-533
Author(s):  
Edwin H. Shaw
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Collagen Fiber ◽  
Fiber Axis ◽  
Cross Linking ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Collagen Lattice ◽  
Rat Tail

Previous work on modification of the collagen lattice, presented at these meetings, has served to confirm the Ramachandran proposal for the structure of this important protein, together with information on the lengths and tensile strengths of these bonds, including hydrogen bonds, hydrophobe bonds, and Vander Waals attractions. Rat tail tendons were suspended in 2 M aqueous solutions of dimethylsulfoxide, acetone, trimethylamineoxide and 1,4-cyclohexanedione, all of which showed evidence of ligation by expansion of the collagen lattice and refinement of the 100 spot in the x-ray diffraction pattern run by rotation on the collagen fiber axis. In the case of trimethylamineoxide and cyclohexanedione, oriented crystallization also occurred, with the long direction of the molecule in the plane perpendicular to the fiber axis of collagen. With the monofunctional ligands, the -C=0 group forms a hydrogen bond to the N-H group in the Ramachandran standard revised model, leaving the methyl groups to form the hydrophobe bond.

Structure of the adducts methylthiourea: 1,4-dioxane (2:1) and 1,1-dimethylthiourea: morpholine (1:1)

2016 ◽  
Vol 71 (8) ◽  
pp. 905-907 ◽  
Author(s):  
Christina Taouss ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Oxygen Atom ◽  
Crystal Structures ◽  
Sulfur Atom ◽  
Layer Structure ◽  
Blocking Effect ◽  
Methyl Groups ◽  
Inversion Symmetry

AbstractThe adducts methylthiourea:1,4-dioxane (2:1) (1) and 1,1-dimethylthiourea:morpholine (1:1) (2) were prepared and their crystal structures determined. In 1, hydrogen bonding involving the methylthiourea molecules leads to the formation of ${\rm{R}}_2^2(8)$ rings and thence to molecular ribbons parallel to [110]. The dioxane molecules accept hydrogen bonds from the remaining NH groups, and their inversion symmetry means that they connect adjacent methylthiourea ribbons, forming a layer structure parallel to (11̅1). In the packing of 2, dimethylthiourea dimers cannot link to each other because of the blocking effect of their methyl groups, but instead are linked indirectly via morpholine molecules, the NH groups of which are simultaneously hydrogen bond acceptors from the remaining NH function of dimethylthiourea and donors towards the sulfur atom of a neighbouring dimer. The overall effect is to form broad ribbons parallel to the a axis, with the morpholine molecules occupying the peripheral positions. The morpholine oxygen atom of 2 is not involved in classical hydrogen bonds.

scholarly journals (Z)-4-Chloro-N-{3-[(4-chlorophenyl)sulfonyl]-2,3-dihydrobenzo[d]thiazol-2-ylidene}benzenesulfonamide

IUCrData ◽  
2017 ◽  
Vol 2 (6) ◽  
Author(s):  
Sydney M. Watkins ◽  
Timothy J. Hagen ◽  
Timothy S. Perkins ◽  
Chong Zheng
Keyword(s):  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Title Compound ◽  
Molecular Conformation ◽  
Methyl Groups ◽  
Compound C ◽  
Centroid Distance ◽  
Phenyl Rings

The title compound, C19H12Cl2N2O4S3, is related to a ditosylated 2-iminobenzothiazole with the two methyl groups on the two phenyl rings replaced by chlorine. There is a weak intramolecular π–π contact between the two phenyl rings, with a centroid-to-centroid distance of 4.004 (2) Å. The dihedral angle between the rings is 9.96 (13)°. An intramolecular C—H...O hydrogen bond stabilizes the molecular conformation.

2-[5-(4-Bromophenyl)-3-methylsulfanyl-1-benzofuran-2-yl]acetic acid

2007 ◽  
Vol 63 (11) ◽  
pp. o4331-o4331
Author(s):  
Hong Dae Choi ◽  
Pil Ja Seo ◽  
Byeng Wha Son ◽  
Uk Lee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Halogen Bond ◽  
Carboxyl Groups ◽  
Dihedral Angles ◽  
Methyl Groups ◽  
Asymmetric Unit ◽  
Compound C ◽  
Independent Molecules ◽  
Hydrolysis Of

The title compound, C17H13BrO3S, was prepared by alkaline hydrolysis of ethyl 2-[5-(4-bromophenyl)-3-methylsulfanyl-1-benzofuran-2-yl]acetate. There are two symmetry-independent molecules in the asymmetric unit. The 4-bromophenyl rings are rotated out of the benzofuran planes, with dihedral angles for the two molecules of 50.22 (8) and 35.4 (1)°. The methyl groups of the methylsulfanyl substituent are almost perpendicular to the plane of the benzofuran fragment [99.5 (2) and 100.8 (2)°] and are slightly tilted towards it. The crystal structure is stabilized by a C—H...O hydrogen bond and a Br...O halogen bond [Br...O = 3.284 (2) Å], and by inversion-related intermolecular O—H...O hydrogen bonds between the carboxyl groups from two symmetry-independent molecules.

Isomer-selective infrared spectroscopy of the cationic trimethylamine dimer to reveal its charge sharing and enhanced acidity of the methyl groups

2014 ◽  
Vol 16 (20) ◽  
pp. 9619-9624 ◽  
Author(s):  
Yoshiyuki Matsuda ◽  
Yuichiro Nakayama ◽  
Naohiko Mikami ◽  
Asuka Fujii
Keyword(s):  
Hydrogen Bond ◽  
Infrared Spectroscopy ◽  
Methyl Groups ◽  
Charge Sharing

The isomer-selective infrared spectroscopy revealed the charge-shared (hemibond) and the C⋯HN hydrogen-bond structures of the trimethylamine dimer cation.

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