Synthesis, X-ray crystal structures, and computational studies of 1,1′-bridged 4,4′-diaryl-2,2′-bibenzimidazoles: building blocks for supramolecular structures

2009 ◽  
Vol 7 (11) ◽  
pp. 2347 ◽  
Author(s):  
Derik K. Frantz ◽  
Ashley A. Sullivan ◽  
Yoshizumi Yasui ◽  
Anthony Linden ◽  
Kim K. Baldridge ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Building Blocks ◽  
Supramolecular Structures ◽  
Computational Studies ◽  
X Ray

Hydrogen Bonds in "Carboxyoximes": the Case of Bomane Derivatives

2000 ◽  
Vol 55 (8) ◽  
pp. 677-684 ◽  
Author(s):  
Maciej Kubicki ◽  
Teresa Borowiak ◽  
Wiesław Z. Antkowiak
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Carboxylic Acids ◽  
Supramolecular Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carboxylic Groups ◽  
Acid Function

Abstract The tendency of forming mixed carboxyl-to-oxime hydrogen bonds was tested on the series of bornane derivatives: one with the acid function only (bornane-2-endo-carboxylic acid), one with the oxime function (2,2′-diethylthiobomane-3-oxime), and one with both oxime and carboxylic functions (bornane-2-oxime-3-endo-carboxylic acid). The crystal structures of these compounds were determined by means of X-ray diffraction. In bornane-2-endo-carboxylic acid and 2,2′-diethylthiobornane-3-oxime 'homogenic' hydrogen bonds were found, and these hydrogen bonds close eight-and six-membered rings, respectively. By contrast, in bornane-2-oxime-3-endo-carboxylic acid 'heterogenic' hydrogen bonds between carboxylic and oxime bonds were found. This carboxylic-oxime, or 'carboxyoxime' system is almost always present in compounds which have both oxime and carboxylic groups; therefore it can be regarded as an element of supramolecular structures (synthon). The presence of such synthons can break the tendency of carboxylic acids and oximes towards crystallizing in centrosymmetric structures.

Preparation and Crystal Structures of the Isotypic Compounds CdXO4 · 2 HgO (X = S, Se)

2004 ◽  
Vol 59 (3) ◽  
pp. 281-285 ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Single Crystals ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Building Blocks ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
X Ray ◽  
Structure Factors

Colourless single crystals of the compounds CdXO4 · 2 HgO (X = S, Se) were obtained under hydrothermal conditions (250 °C, 5 d), starting from stoichiometric amounts of HgO, CdSO4 ·7H2O and CdSeO4 ·2H2O, respectively. The crystal structures were determined from X-ray diffraction data sets. The CdXO4 · 2HgO compounds crystallise isotypically with two formula units in space group P1̅ (# 2) [CdSO4 · 2HgO (CdSeO4 · 2HgO): a = 6.793(2) (6.9097(5)) Å , b = 7.205(2) (7.1786(6)) Å , c=7.359(2) (7.4556(6)) Å ,α =73.224(6) (74.586(2))°, β =66.505(6) (68.229(1))°, γ =63.054(5) (63.886(1))°, 1670 (1786) structure factors, 92 parameters, R[F2 > 2σ(F2)] = 0.0379 (0.0244)] and are made up from zig-zag [O-Hg-O]∞ chains with very short bonds of d̅(Hg-O) 2.025 Å , distorted [CdO6] octahedra (d̅(Cd-O)= 2.297 Å ), and XO4 tetrahedra (d̅(S-O)= 1.458 Å , d̅(Se-O)= 1.633 Å ) as the main building blocks. The CdXO4 ·2HgO compounds reveal no structural relationship with the corresponding HgXO4 ·2HgO phases

Computational studies for crystal structures of helicate lanthanide complexes based on X-ray analyses

2021 ◽  
Author(s):  
Naofumi Nakayama ◽  
Masahiro Hijikata ◽  
Hitomi Ohmagari ◽  
Hideyuki Tanaka ◽  
Yudai Inazuka ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Lanthanide Complexes ◽  
Computational Studies ◽  
X Ray

Self-Assembling l-d-l-Tripeptides Dance the Twist

Synlett ◽  
2020 ◽  
Vol 31 (05) ◽  
pp. 434-438 ◽  
Author(s):  
Maria C. Cringoli ◽  
Ottavia Bellotto ◽  
Rita De Zorzi ◽  
Attilio V. Vargiu ◽  
Silvia Marchesan
Keyword(s):  
Molecular Dynamics ◽  
Amino Acids ◽  
Single Crystal ◽  
Self Assembly ◽  
Building Blocks ◽  
Supramolecular Structures ◽  
X Ray Diffraction ◽  
Supramolecular Materials ◽  
X Ray ◽  
Self Assembling

Minimalistic peptides composed of d- and l-amino acids are attractive building blocks for functional supramolecular materials, including catalysts. d-Amino acids have long been known to promote turn conformations in peptides, yet unexpected twists continue to emerge on their effects on self-assembly. The combination of single-crystal X-ray diffraction and full-atom molecular dynamics have finally unraveled fine details of how l-d-l-tripeptides visit different conformations in solution and establish key interactions in supramolecular structures.

Synthesis of novel optically pure β-lactams

2005 ◽  
Vol 83 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Yan Yang ◽  
Fengyun Wang ◽  
Fernande D Rochon ◽  
Margaret M Kayser
Keyword(s):  
Crystal Structures ◽  
Building Blocks ◽  
Baker’S Yeast ◽  
Staudinger Reaction ◽  
Baker's Yeast ◽  
X Ray ◽  
Pure Compounds ◽  
Optically Pure ◽  
Aspartyl Proteases

Several new β-lactams were synthesized as racemates via a Staudinger reaction. The corresponding optically pure compounds were obtained in subsequent biotransformation steps either through baker's yeast reduction or lipase resolution. Their absolute configurations were established. The X-ray crystal structures of three new substituted β-lactams are reported here. These compounds represent key building blocks for a variety of medicinally important molecules, including inhibitors of aspartyl proteases and Taxol® analogues.Key words: optically pure β-lactams, lipase resolutions, baker's yeast reductions, Staudinger reaction.

Synthesis and Crystal Structures of Indole Derivatives and Indolo[2,3-a]carbazoles as Building Blocks to or as Protein Kinase C Inhibitors

1997 ◽  
Vol 52 (10) ◽  
pp. 1251-1258 ◽  
Author(s):  
Dieter Schollmeyer ◽  
Young-Shin Kim ◽  
Ulf Pindur
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Crystal Structures ◽  
Building Blocks ◽  
Indole Derivatives ◽  
X Ray ◽  
Protein Kinase C Inhibitors ◽  
Kinase C ◽  
Structure Activity ◽  
New Protein

The functionalization reactions of 2,2’-bisindolyls with electrophiles and dienophiles gave rise to a group of new protein kinase C inhibitors. Rationalization of structure activity relationships and of some mechanistical aspects concerning the synthesis X ray crystal structures are described for 2,2’-bisindolyl derivatives 1-3 and 6 and for indolo[a]carbazoles 4 and 5.

scholarly journals Assembling Polyiodides and Iodobismuthates Using a Template Effect of a Cyclic Diammonium Cation and Formation of a Low-Gap Hybrid Iodobismuthate with High Thermal Stability

Molecules ◽  
2020 ◽  
Vol 25 (12) ◽  
pp. 2765
Author(s):  
Tatiana A. Shestimerova ◽  
Andrei V. Mironov ◽  
Mikhail A. Bykov ◽  
Anastasia V. Grigorieva ◽  
Zheng Wei ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Building Blocks ◽  
High Thermal Stability ◽  
X Ray Diffraction ◽  
Template Effect ◽  
X Ray ◽  
Solvent Water ◽  
Molecular Solid

Exploiting a template effect of 1,4-diazacycloheptane (also known as homopiperazine, Hpipe), four new hybrid iodides, (HpipeH2)2Bi2I10·2H2O, (HpipeH2)I(I3), (HpipeH2)3I6·H2O, and (HpipeH2)3(H3O)I7, were prepared and their crystal structures were solved using single crystal X-ray diffraction data. All four solid-state crystal structures feature the HpipeH22+ cation alternating with Bi2I104–, I3–, or I– anions and solvent water or H3O+ cation. HpipeH22+ assembles anionic and neutral building blocks into polymer structures by forming four strong (N)H···I and (N)H···O hydrogen bonds per cation, with the H···I distances ranging from 2.44 to 2.93 Å and H···O distances of 1.88–1.89 Å. These hydrogen bonds strongly affect the properties of compounds; in particular, in the case of (HpipeH2)2Bi2I10·2H2O, they ensure narrowing of the band gap down to 1.8 eV and provide high thermal stability up to 240 °C, remarkable for a hydrated molecular solid.

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