Solution and Solid State Studies on the Interactions of Protonated Cytosine Salts. IV. Asymmetric Interbase Hydrogen Bonding and Interpyrimidine Base Stacking in Triply Hydrogen-Bonded Cytosine Complexes. Crystal and Molecular Structure of Bis[1-Methylcytosine, 1-Methylcytosinium] Hexafluorosilicate Dihydrate

1980 ◽  
Vol 17 (2) ◽  
pp. 113-134 ◽  
Author(s):  
Thomas J. Kistenmacher ◽  
Miriam Rossi ◽  
Chian C. Chiang ◽  
John P. Caradonna ◽  
Luigi G. Marzilli
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Crystal And Molecular Structure ◽  
Base Stacking ◽  
Protonated Cytosine ◽  
Hydrogen Bonded

Crystal and molecular structure of bis(acetylacetone)ethylenediimine: intramolecular ionic hydrogen bonding in solid state

2004 ◽  
Vol 688 (1-3) ◽  
pp. 207-211 ◽  
Author(s):  
Saim Özkar ◽  
Dinçer Ülkü ◽  
Leyla Tatar Yıldırım ◽  
Nermin Biricik ◽  
Bahattin Gümgüm
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Crystal And Molecular Structure ◽  
Ionic Hydrogen Bonding

Crystal and molecular structure of 5-carboxy-2-thiouracil monohydrate

2001 ◽  
Vol 216 (2) ◽  
Author(s):  
Edward R. T. Tiekink
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Structure Determination ◽  
Crystal And Molecular Structure ◽  
Layer Structure ◽  
Two Dimensional ◽  
Base Stacking

AbstractThe structure determination of 5-carboxy-2-thiouracil shows it to exist in the lactam-thione form. Extensive hydrogen bonding involving all possible donors and acceptors leads to the formation of interconnected 8- (x2), 10-, 16- and 20-membered rings and a two-dimensional layer structure; no evidence for base stacking was found.

scholarly journals Nanomechanics of negatively supercoiled diaminopurine-substituted DNA

2021 ◽  
Author(s):  
Domenico Salerno ◽  
Francesco Mantegazza ◽  
Valeria Cassina ◽  
Matteo Cristofalo ◽  
Qing Shao ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Single Molecule ◽  
Conformational Dynamics ◽  
Persistence Length ◽  
Base Stacking ◽  
Base Pairs ◽  
Left Handed ◽  
Negative Supercoiling ◽  
Mechanical Dynamics ◽  
Hydrogen Bonded

ABSTRACTSingle molecule experiments have demonstrated a progressive transition from a B- to an L-form helix as DNA is gently stretched and progressively unwound. Since the particular sequence of a DNA segment influences both base stacking and hydrogen bonding, the conformational dynamics of B-to-L transitions should be tunable. To test this idea, DNA with diaminopurine replacing adenine was synthesized to produce linear fragments with triply hydrogen-bonded A:T base pairs. Triple hydrogen bonding stiffened the DNA by 30% flexurally. In addition, DAP-substituted DNA formed plectonemes with larger gyres for both B- and L-form helices. Both unmodified and DAP-substituted DNA transitioned from a B- to an L-helix under physiological conditions of mild tension and unwinding. This transition avoids writhing by DNA stretched and unwound by enzymatic activity. The intramolecular nature and ease of this transition likely prevent cumbersome topological rearrangements in genomic DNA that would require topoisomerase activity to resolve. L-DNA displayed about tenfold lower persistence length indicating it is much more contractile and prone to sharp bends and kinks. However, left-handed DAP DNA was twice as stiff as unmodified L-DNA. Thus, significantly doubly and triply hydrogen bonded segments have very distinct mechanical dynamics at physiological levels of negative supercoiling and tension.

Reaction of N,N′-dihydroxy-.N,N′-dimethylmethanediamine with phenylboronic acid and the crystal and molecular structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine

1989 ◽  
Vol 67 (11) ◽  
pp. 1959-1963 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Exact Formula ◽  
Full Matrix ◽  
Space Group ◽  
Hydrogen Bonded

The reaction of N,N′-dihydroxy-N,N′-dimethylmethanediamine with phenylboronic acid leads to the product 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane rather than the expected product 1,5-dimethyl-3-phenyl-1,5-diaza-2,4-dioxa-3-boracyclohexane. The structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine has been determined and is discussed in terms of its reaction with PhB(OH)2. Crystals of N,N′-dihydroxy-N,N′-dimethylmethanediamine are tetragonal, a = 8.5346(3), c = 8.4178(7) Å, Z = 4, space group P421c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.036 and Rw of 0.038 for 333 reflections with I ≥ 3σ(I). The structure consists of hydrogen-bonded dimers having exact [Formula: see text] symmetry. Keywords: N,N′-dihydroxy-N,N′-dimethylmethanediamine, crystal structure.

1.4-Dioxan · H2O · SbCl5; Schwingungsspektren, Kristall- und Molekülstruktur / 1,4-Dioxane · H2O · SbCl5; Vibrational Spectra, Crystal and Molecular Structure

1978 ◽  
Vol 33 (2) ◽  
pp. 136-139 ◽  
Author(s):  
W. Schwarz ◽  
A. Schmidt ◽  
G. E. Binder
Keyword(s):  
Molecular Structure ◽  
Vibrational Spectra ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Addition Compound ◽  
Space Group ◽  
Lattice Constants ◽  
Chloride Water ◽  
Hydrogen Bonded

The preparation of the 1:1:1 addition compound 1 of 1,4-dioxane, water and antimony(V) chloride is described. 1 crystallizes in the space group Cmcm with the lattice constants a = 8.494, b = 11.453, c = 13.030 Å with four formula units in the unit cell. The dioxane is strongly hydrogen bonded to an antimony(V) chloride water adduct. The vibrational spectra of the solid are assigned

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