On the nature of M–CO(lone pair)⋯π(arene) interactions in the solid state of fluorinated oxaphosphirane complexes

CrystEngComm ◽  
2015 ◽  
Vol 17 (35) ◽  
pp. 6736-6743 ◽  
Author(s):  
Cristina Murcia-García ◽  
Antonio Bauzá ◽  
Antonio Frontera ◽  
Rainer Streubel
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Lone Pair ◽  
X Ray ◽  
High Level

The X-ray structures of several oxaphosphirane tungsten(0) complexes exhibit interesting intramolecular W–CO(lone pair)ċπ(arene) interactions that have been rationalized by means of high-level DFT calculations and the CSD.

Configurations and conformations of glycosyl sulfoxides

2010 ◽  
Vol 88 (11) ◽  
pp. 1154-1174 ◽  
Author(s):  
Hong Liang ◽  
Micheline MacKay ◽  
T. Bruce Grindley ◽  
Katherine N. Robertson ◽  
T. Stanley Cameron
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Gas Phase ◽  
Density Functional ◽  
Lone Pair ◽  
Azido Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Comparison Of The Results ◽  
P Type

X-ray crystallographic studies of two axial glycosyl sulfoxides having RS configurations (derivatives of phenyl 2-azido-2-deoxy-1-thio-α-d-galactopyranoside S-oxide) show that they adopt anti conformations in the solid state, in contrast to previous observations and assumptions. Density functional theory (DFT) calculations at the B3lYP6–311G+(d,p)/6–31G(d) level confirm that anti conformations of both phenyl and methyl RS glycosyl sulfoxides of 2-azido-2-deoxy-α-d-pyranosides are more stable than exo-anomeric conformations in the gas phase. 1D NOE measurements indicate that the more polar exo-anomeric conformers are only populated to a slight extent in solution. The anti conformations are distorted so that the glycosyl substituents are closer to being eclipsed with H1. This distortion allows S n → σ* overlap if the sulfur lone pair is a p-type lone pair. Evidence for this overlap comes from short C1–S bond distances, as short as the comparable bond distances in the X-ray crystal structure and in the results from DFT calculations for the SS glycoside, which does adopt the expected exo-anomeric conformation, both in the solid state and in solution, and has normal n → σ* overlap. For 2-deoxy derivatives not bearing a 2-azido group, gas-phase DFT calculations at the same level indicate that the anti- and exo-anomeric conformers have comparable stabilities. Comparison of the results of the two series shows that electronegative substituents in equatorial orientations at C2 destabilize conformations with parallel S–O arrangements, the conformation favored by having an endocyclic C–O dipole antiparallel to the S–O dipole, by about 2.5 kcal mol–1 (1 cal = 4.184 J). An equatorial glycosyl sulfoxide, (SS) phenyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-1-thio-β-d-glucopyranoside S-oxide, also adopts an anti conformation in the solid state as shown by X-ray diffraction. It also adopts this conformation in solution, in contrast to studies of other equatorial glycosyl sulfoxides.

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

The solid state structures of the high and low temperature phases of dimethylcadmium

2016 ◽  
Vol 52 (66) ◽  
pp. 10144-10146 ◽  
Author(s):  
Felix Hanke ◽  
Sarah Hindley ◽  
Anthony C. Jones ◽  
Alexander Steiner
Keyword(s):  
Solid State ◽  
Low Temperature ◽  
Dft Calculations ◽  
Methyl Groups ◽  
X Ray ◽  
Solid State Structures

X-ray structures and DFT calculations show that the HT phase is of Me2Cd is two-dimensionally disordered, while the LT phase is ordered. Both phases contain linearly coordinated cadmium atoms; methyl groups are staggered in the HT form and eclipsed in the LT-form.

scholarly journals Tautomerism and Self-Association in the Solution of New Pinene-Bipyridine and Pinene-Phenanthroline Derivatives

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 298
Author(s):  
Atena B. Solea ◽  
Ivan Cornu ◽  
Vera Deneva ◽  
Aurelien Crochet ◽  
Katharina M. Fromm ◽  
...  
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Structure Determination ◽  
Tautomeric Equilibrium ◽  
Dft Studies ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Self Association

Two novel pinene-type ligands have been synthesized and their tautomeric and self-associating behavior studied in solution and in the solid state. The first ligand, an acetylated derivative of 5,6-pinene-bipyridine, displays keto-enol tautomerism in solution. This tautomeric equilibrium was studied by NMR and UV-Vis spectroscopy in various solvents, and the results were compared with the ones obtained through DFT calculations. The second ligand was obtained by an unusual oxidation of the phenanthroline unit of a pinene-phenanthroline derivative. This compound exists as a single tautomer in solution and aggregates both in solution (as observed by NMR) and in the solid state through H-bonding as observed by X-ray structure determination and confirmed by DFT studies.

Anagostic Interactions in Alkyl-Fluorenyl-Substituted N‐Heterocyclic Carbene Complexes of Palladium(II)

2020 ◽  
Vol 73 (6) ◽  
pp. 579
Author(s):  
Hamzé Almallah ◽  
Eric Brenner ◽  
Dominique Matt ◽  
Mohamad Jahjah ◽  
Akram Hijazi ◽  
...  
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Single Crystal ◽  
Spectroscopic Methods ◽  
Palladium Atom ◽  
Ring Plane ◽  
Carbene Complexes ◽  
X Ray ◽  
Methylene Groups ◽  
Coordination Plane

Two imidazolylidene (Im) complexes of the general formula trans-[PdX2(Im)(pyridine)] (X=Cl (2), Br (3)), in which the N-heterocyclic carbene ligand has one of its nitrogen atoms substituted by a bulky 9-propyl-9-fluorenyl group (PrF), have been prepared and fully characterised by spectroscopic methods and single-crystal X-ray structure analyses. In the solid state, the Im ring plane and the coordination plane of each complex are nearly orthogonal, thereby minimising the steric interactions between the N-substituents and the halide atoms. In both structures two methylenic C–H bonds sit near the dz2 axis point to the palladium atom, resulting in CH⋯Pd separations of 2.58/2.95Å in 2 and 2.74/2.74Å in 3. NMR measurements and DFT calculations indicate that these methylene groups are involved in anagostic CH⋯M interactions but not in significant H⋯X bonding.

Structural refinement of the RT LaOF phases by coupling powder X-Ray diffraction, 19F and 139La solid state NMR and DFT calculations of the NMR parameters

2015 ◽  
Vol 44 (47) ◽  
pp. 20675-20684 ◽  
Author(s):  
Jamal Dabachi ◽  
Monique Body ◽  
Jens Dittmer ◽  
Franck Fayon ◽  
Christophe Legein
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Solid State Nmr ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Parameters

The structures of the RT LaOF phases have been refined by coupling XRPD, multinuclear solid state NMR and DFT calculations.

scholarly journals Polymorphism in 8-hydroxyquinolin-2(1H)-one by X-ray crystallography, solid-state NMR and DFT calculations

2011 ◽  
Vol 67 (a1) ◽  
pp. C816-C817
Author(s):  
R. M. Claramunt ◽  
M. Á García ◽  
M. Á Farrán ◽  
C. I. Nieto ◽  
M. C. Torralba ◽  
...  
Keyword(s):  
Solid State ◽  
Dft Calculations ◽  
Solid State Nmr ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Substituent Effects in 3,3’ Bipyrazole Derivatives. X-ray Crystal Structures, Molecular Properties and DFT Analysis

2021 ◽  
Vol 68 (3) ◽  
pp. 718-727
Author(s):  
Ibrahim Bouabdallah ◽  
Tarik Harit ◽  
Mahmoud Rahal ◽  
Fouad Malek ◽  
Monique Tillard ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Solid State ◽  
Dft Calculations ◽  
Single Crystal ◽  
Crystal Structures ◽  
Density Functional ◽  
Substituent Effects ◽  
Functional Theory ◽  
X Ray

The single crystal X-ray structure of new 1,1’-bis(2-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 1, is triclinic P I–, a = 7.7113(8), b = 12.3926(14), c = 12.9886(12) Å, α = 92.008(8), β = 102.251(8), γ = 99.655(9)°. The structural arrangement is compared to that of 5,5’-diisopropyl-3,3’-bipyrazole, 5, whose single crystal structure is found tetragonal I41/a, a = b = 11.684(1), c = 19.158(1) Å. The comparison is also extended to the structures previously determined for 1,1’-bis(2-nitrophenyl)-5,5’-propyl-3,3’-bipyrazole, 2, 1,1’-bis(4-nitrophenyl)-5,5’-diisopropyl-3,3’-bipyrazole, 3, and 1,1’-bis(benzyl)-5,5’-diisopropyl-3,3’-bipyrazole, 4. Density Functional Theory (DFT) calculations are used to investigate the molecular geometries and to determine the global reactivity parameters. The geometry of isolated molecules and the molecular arrangements in the solid state are analyzed according to the nature of the groups connected to the bipyrazole core.

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