Do Secondary Electrostatic Interactions Influence Multiple Dihydrogen Bonds? AA−DD Array on an Amine‐Borane Aza‐Coronand: Theoretical Studies and Synthesis

ChemPhysChem ◽  
2021 ◽  
Author(s):  
Giovanni Bella ◽  
Antonio Santoro ◽  
Francesco Nicolò ◽  
Giuseppe Bruno ◽  
Massimiliano Cordaro
2016 ◽  
Vol 18 (37) ◽  
pp. 26057-26068 ◽  
Author(s):  
Helena Dodziuk ◽  
Kenneth Ruud ◽  
Tatiana Korona ◽  
Taye B. Demissie

Theoretical studies of complexes of the enantiomers of CHFClBr with C82-3 show that the too large guests are stabilized in the C82cage by electrostatic interactions. The sign of v(CH) stretching vibration of S-CHFClBr@C82-3 in the VCD spectrum is reversed as compared to that of the free guest. Spectra of the complexes exhibit differences.


Author(s):  
Brigid R. Heywood ◽  
S. Champ

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.


1998 ◽  
Vol 94 (5) ◽  
pp. 839-842
Author(s):  
MILAN REMKO
Keyword(s):  

1998 ◽  
Vol 80 (08) ◽  
pp. 310-315 ◽  
Author(s):  
Marie-Christine Bouton ◽  
Christophe Thurieau ◽  
Marie-Claude Guillin ◽  
Martine Jandrot-Perrus

SummaryThe interaction between GPIb and thrombin promotes platelet activation elicited via the hydrolysis of the thrombin receptor and involves structures located on the segment 238-290 within the N-terminal domain of GPIbα and the positively charged exosite 1 on thrombin. We have investigated the ability of peptides derived from the 269-287 sequence of GPIbα to interact with thrombin. Three peptides were synthesized, including Ibα 269-287 and two scrambled peptides R1 and R2 which are comparable to Ibα 269-287 with regards to their content and distribution of anionic residues. However, R2 differs from both Ibα 269-287 and R1 by the shifting of one proline from a central position to the N-terminus. By chemical cross-linking, we observed the formation of a complex between 125I-Ibα 269-287 and α-thrombin that was inhibited by hirudin, the C-terminal peptide of hirudin, sodium pyrophosphate but not by heparin. The complex did not form when γ-thrombin was substituted for α-thrombin. Ibα 269-287 produced only slight changes in thrombin amidolytic activity and inhibited thrombin binding to fibrin. R1 and R2 also formed complexes with α-thrombin, modified slightly its catalytic activity and inhibited its binding to fibrin. Peptides Ibα 269-287 and R1 inhibited platelet aggregation and secretion induced by low thrombin concentrations whereas R2 was without effect. Our results indicate that Ibα 269-287 interacts with thrombin exosite 1 via mainly electrostatic interactions, which explains why the scrambled peptides also interact with exosite 1. Nevertheless, the lack of effect of R2 on thrombin-induced platelet activation suggests that proline 280 is important for thrombin interaction with GPIb.


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