The Influence of the Stereochemistry of Alanine Residue on the Solid State Conformation and Crystal Packing of Opioid Peptides Containingd-Ala orl-Ala in Message Domain – XRD and NMR Study

2011 ◽  
Vol 115 (32) ◽  
pp. 9910-9919 ◽  
Author(s):  
Katarzyna Trzeciak-Karlikowska ◽  
Anna Bujacz ◽  
Włodzimierz Ciesielski ◽  
Grzegorz D. Bujacz ◽  
Marek J. Potrzebowski
Keyword(s):  
Solid State ◽  
Opioid Peptides ◽  
Crystal Packing ◽  
Alanine Residue ◽  
Nmr Study ◽  
Solid State Conformation

Solid State Conformation and Crystal Packing of Methyl-Substituted Quaterthiophenes

2000 ◽  
Vol 348 (1) ◽  
pp. 137-151 ◽  
Author(s):  
E. A. Marseglia ◽  
F. Grepioni ◽  
E. Tedesco ◽  
D. Braga
Keyword(s):  
Solid State ◽  
Crystal Packing ◽  
Solid State Conformation

Solid-State NMR, X-Ray Diffraction, and Theoretical Studies of Neutral Mononuclear Molecular Bis(triphenylphosphine)silver(I) Mono-Carboxylate and -Nitrate Systems

2020 ◽  
Vol 73 (6) ◽  
pp. 556
Author(s):  
Simon Grabowsky ◽  
Allan H. White ◽  
Peter C. Healy ◽  
Kim M. Lapere ◽  
Seik Weng Ng ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Crystal Packing ◽  
Computational Modelling ◽  
Inverse Correlation ◽  
X Ray Diffraction ◽  
Weakly Bound ◽  
X Ray ◽  
Nmr Study ◽  
Structure Determinations

Neutral mononuclear molecular silver(i) carboxylate complexes of the form [(Ph3P)2Ag(O2XY)] with O2XY=O2CCH2Ph, O2CCHPh2, O2CC(CH3)3, O2CCH2C(CH3)3, and O2CCF3 (compounds 1–4 and 5β) have been investigated in the solid state using single-crystal X-ray structure determinations, 1D 31P CPMAS NMR and 2D 31P–31P CPCOSY NMR measurements, and ab initio computational modelling. The results show that these complexes contain P2AgO2 molecular cores with four-coordinate silver in which the carboxylate ligands are weakly bound to the silver atoms via the two oxygen atoms giving rise to unsymmetrical chelate units. Crystal structure determinations and solid-state NMR spectra have also been analysed for the mononuclear molecular silver(i) nitrate complex [(Ph3P)2Ag(O2NO)] (9α) and two polymorphs of its toluene monosolvate (11α, β). In 9α, the two PPh3 ligands are of the same chirality, whereas in 11α, β, they are opposed. The crystalline environments in the polymorphs have been explored by way of Hirshfeld surface analyses, after quantum-mechanical isolated-molecule calculations had shown that although the molecular energies of the experimental geometries of 9α, and 11α, β are significantly different from each other and from the energies of the optimized geometries, the latter, in contrast, do not differ significantly from each other despite the conformational isomerism. It has further been shown using 9α as an example that the energy dependence on variation of the P–Ag–P angle over a range of ~15° is only ~5 kJ mol−1. All this indicates that the forces arising from crystal packing result in significant perturbations in the experimental geometries, but do not alter the stereoisomerism caused by the donor atom array around the Ag atom. In the NMR study, a strong inverse correlation has been found between 1J(107/109Ag,31P) and the Ag–P bond length across all carboxylate and nitrate compounds.

Effects of alcohols on membranes of water/surfactant/alcohol ternary systems. A solid state deuterium NMR study

1994 ◽  
Vol 91 ◽  
pp. 888-894
Author(s):  
F Auguste ◽  
EJ Dufourc ◽  
AM Bellocq
Keyword(s):  
Solid State ◽  
Ternary Systems ◽  
Deuterium Nmr ◽  
Nmr Study

The Influence of Nitrogen Position on Charge Carrier Mobility in Enantiopure Aza[6]helicene Crystals

2018 ◽  
Author(s):  
Francesco Salerno ◽  
Beth Rice ◽  
Julia Schmidt ◽  
Matthew J. Fuchter ◽  
Jenny Nelson ◽  
...  
Keyword(s):  
Solid State ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Chemical Structure ◽  
Crystal Packing ◽  
Charge Carrier Mobility ◽  
Individual Factor ◽  
Charge Mobility ◽  
Order Of Magnitude ◽  
Small Change

<p>The properties of an organic semiconductor are dependent on both the chemical structure of the molecule involved, and how it is arranged in the solid-state. It is challenging to extract the influence of each individual factor, as small changes in the molecular structure often dramatically change the crystal packing and hence solid-state structure. Here, we use calculations to explore the influence of the nitrogen position on the charge mobility of a chiral organic molecule when the crystal packing is kept constant. The transfer integrals for a series of enantiopure aza[6]helicene crystals sharing the same packing were analysed in order to identify the best supramolecular motifs to promote charge carrier mobility. The regioisomers considered differ only in the positioning of the nitrogen atom in the aromatic scaffold. The simulations showed that even this small change in the chemical structure has a strong effect on the charge transport in the crystal, leading to differences in charge mobility of up to one order of magnitude. Some aza[6]helicene isomers that were packed interlocked with each other showed high HOMO-HOMO integrals (up to 70 meV), whilst molecules arranged with translational symmetry generally afforded the highest LUMO-LUMO integrals (40 - 70 meV). As many of the results are not intuitively obvious, a computational approach provides additional insight into the design of new semiconducting organic materials.</p>

ChemInform Abstract: EFFECT OF CRYSTAL PACKING ON THE SOLID-STATE SPECTRAL PROPERTIES OF VICINAL DIKETONES

1984 ◽  
Vol 15 (4) ◽  
Author(s):  
J. I. CROWLEY ◽  
R. D. BALANSON ◽  
J. J. MAYERLE
Keyword(s):  
Solid State ◽  
Spectral Properties ◽  
Crystal Packing

scholarly journals Convenient Access to Functionalized Non-Symmetrical Atropisomeric 4,4′-Bipyridines

Compounds ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 58-74
Author(s):  
Emmanuel Aubert ◽  
Emmanuel Wenger ◽  
Paola Peluso ◽  
Victor Mamane
Keyword(s):  
Solid State ◽  
Intermolecular Interactions ◽  
Medicinal Chemistry ◽  
Crystal Packing ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Halogen Bonds ◽  
Cross Coupling Reactions ◽  
Cyano Groups ◽  
Post Functionalization

Non-symmetrical chiral 4,4′-bipyridines have recently found interest in organocatalysis and medicinal chemistry. In this regard, the development of efficient methods for their synthesis is highly desirable. Herein, a series of non-symmetrical atropisomeric polyhalogenated 4,4′-bipyridines were prepared and further functionalized by using cross-coupling reactions. The desymmetrization step is based on the N-oxidation of one of the two pyridine rings of the 4,4′-bipyridine skeleton. The main advantage of this methodology is the possible post-functionalization of the pyridine N-oxide, allowing selective introduction of chlorine, bromine or cyano groups in 2- and 2′-postions of the chiral atropisomeric 4,4′-bipyridines. The crystal packing in the solid state of some newly prepared derivatives was analyzed and revealed the importance of halogen bonds in intermolecular interactions.

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