scholarly journals Structural proof of a [C–F–C]+ fluoronium cation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kurt F. Hoffmann ◽  
Anja Wiesner ◽  
Carsten Müller ◽  
Simon Steinhauer ◽  
Helmut Beckers ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Vibrational Spectra ◽  
Spectroscopic Studies ◽  
Covalent Bonding ◽  
Model System ◽  
Crystallographic Analysis ◽  
Carbon Centers ◽  
Positively Charged

AbstractOrganic fluoronium ions can be described as positively charged molecules in which the most electronegative and least polarizable element fluorine engages in two partially covalent bonding interactions to two carbon centers. While recent solvolysis experiments and NMR spectroscopic studies on a metastable [C–F–C]+ fluoronium ion strongly support the divalent fluoronium structure over the alternative rapidly equilibrating classical carbocation, the model system has, to date, eluded crystallographic analysis to confirm this phenomenon in the solid state. Herein, we report the single crystal structure of a symmetrical [C–F–C]+ fluoronium cation. Besides its synthesis and crystallographic characterization as the [Sb2F11]− salt, vibrational spectra are discussed and a detailed analysis concerning the nature of the bonding situation in this fluoronium ion and its heavier halonium homologues is performed, which provides detailed insights on this molecular structure.

The Meisenheimer rearrangement in heterocyclic synthesis. II. Synthesis and X-ray crystal structure of a tetrahydro-1H-2,3-benzoxazocine and preparation of a hexahydro-2,3-benzoxazonine

1980 ◽  
Vol 33 (6) ◽  
pp. 1323 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
PE Davies ◽  
CLWAH Raston
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Acetic Acid ◽  
Crystal And Molecular Structure ◽  
Phosphorus Oxychloride ◽  
Crystallographic Analysis ◽  
Heterocyclic Synthesis ◽  
Reaction Conditions ◽  
X Ray ◽  
Heterocyclic Derivatives

The heterocyclic derivatives, 8,9-dimethoxy-3-methyl-1-phenyl-3,4,5,6- tetrahydro-1H-2,3-benzoxazocine(3a) and 9,10-dimethoxy-3-methyl-1- phenyl-1,3,4,5,6,7-hexahydro-2,3-benzoxazonine (3b),examples of two new ring systems, have been prepared by Meisenheimer rearrangement of the corresponding 2-benzazepine and 2-benzazocine N-oxide derivatives (2a) and (2b). The Bischler-Napieralski-type cyclization reaction was used in the preparation of the tertiary amine precursors of these N-oxides reaction conditions for the cyclization were critical and phosphorus oxychloride in refluxing butanenitrile was found to give the best yields of the seven- or eight-membered cyclic imine intermediates. Reductive cleavage of the benzoxazocine derivative (3a) with zinc in acetic acid followed by N-methylation gave the expected product, [2-{3- (dimethylamino)propyl}-4,5-di-methoxyphenyl]phenylmethanol (12). The crystal and molecular structure of (3a) has been determined by X-ray crystallographic analysis.

Syntheses and vibrational spectra of some tris(alkanethiolato)mercurate(II) complexes, and crystal structure of the Hexakis(methanethiolato)dimercurate(II) dianion

1984 ◽  
Vol 37 (8) ◽  
pp. 1607 ◽  
Author(s):  
GA Bowmaker ◽  
IG Dance ◽  
BC Dobson ◽  
DA Rogers
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Vibrational Spectra ◽  
Crystal Data ◽  
Tetrahedral Geometry ◽  
Space Group ◽  
Spectroscopic Evidence ◽  
Distorted Tetrahedral Geometry ◽  
Complex Anions

The complexes [cation] [Hg(SR)3](R = Me, cation = Et4N+; R = But, cation = Et4N+, Bu4N+, [N(Ph3P)2]+) have been prepared. The crystal structure of the methanethiolate complex shows that it contains centrosymmetric dinuclear anions [(MeS)2Hg(�-SMe)2Hg(SMe)2]2- with distorted tetrahedral geometry about the mercury atoms. Vibrational spectroscopic evidence suggests that this complex dissociates on dissolution in ethanol to give mononuclear [Hg(SMe)3]- species. The ButS- complexes appear to exist as mononuclear [Hg(SBut)3]- species both in the solid state and in solution. The metal-sulfur stretching frequencies are assigned for all of the complexes studied, and the vibrational spectra are discussed in terms of the structures of the complex anions involved. Crystal data for [(C2H5)4N]2Hg2(SCH3)6 : a 8.656(5), b gS130(6), c 12.368(8) �; α 102.16(4), β 105.51(4), γ 105.29(4)�; space group P1, Z 1, R 0.034, Rw 0.042.

Crystal and Molecular Structure of 3-(N-Methoxy-N-methylcarbamoyl)- 2,2,5,5-tetramethyl-1-oxy-pyrroline

2010 ◽  
Vol 65 (4) ◽  
pp. 475-478
Author(s):  
Guido D. Frey ◽  
Eberhardt Herdtweck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Crystal And Molecular Structure ◽  
Layer Structure ◽  
Nitroxide Radical ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Stable Nitroxide

The crystal structure of the stable nitroxide radical 3-(N-methoxy-N-methylcarbamoyl)-2,2,5,5- tetramethyl-1-oxy-pyrroline was determined from single-crystal X-ray data: orthorhombic, space group Pbca (no. 61), a = 9.0213(1), b = 12.8625(1), c = 21.2406(2) Å, V = 2464.68(4) Å3 and Z = 8. The adjacent molecules assemble to a supramolecular layer structure in the solid state, linked by two intermolecular C-H...O hydrogen bonds.

Quinones and quinone methides. X. The crystal structure of a dimeric oxidation product from 2,4-Bis(1,1-dimethylethyl)-6-[(4-methoxyphenyl)methyl]phenol

1984 ◽  
Vol 37 (12) ◽  
pp. 2593
Author(s):  
RY Wong ◽  
L Jurd
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Oxidation Product ◽  
Crystallographic Analysis ◽  
Quinone Methides ◽  
X Ray ◽  
A Minor

The molecular structure of a minor oxidation product of the insect sterilant 2,4-bis(1,1-dimethylethyl) 6-[(4-methoxyphenyl)methyl]phenol has been established as (�)-cis-1,3,6,8-tetrakis(1,1-dimethyl-ethyl)-4b,9b-bis(4-methoxyphenyl)-4b,9b-dihydrobenzofuro[3,2-b]benzofuran by means of X-ray crystallographic analysis.

scholarly journals Two coordination compounds of SnCl2 with 4-methylpyridine N-oxide

2021 ◽  
Vol 77 (2) ◽  
pp. 91-95
Author(s):  
Felix Henkel ◽  
Hans Reuter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Solid State ◽  
Coordination Compounds ◽  
Bond Angle ◽  
Lewis Base ◽  
One Dimensional ◽  
Bonding Parameters ◽  
Solid State Structures ◽  
Endocyclic Bond

In the solid-state structures of catena-poly[[dichloridotin(II)]-μ2-(4-methylpyridine N-oxide)-κ2 O:O], [SnCl2(C6H7NO)] n , 1, and dichloridobis(4-methylpyridine N-oxide-κO)tin(II), [SnCl2(C6H7NO)2], 2, the bivalent tin atoms reveal a seesaw coordination with both chlorine atoms in equatorial and the Lewis base molecules in axial positions. While the Sn—Cl distances are almost identical, the Sn—O distances vary significantly as a result of the different bonding modes (μ2 for 1, μ1 for 2) of the 4-methylpyridin-N-oxide molecules, giving rise to a one-dimensional coordination polymer for the 1:1 adduct, 1, and a molecular structure for the 1:2 adduct, 2. The different coordination modes also influence the bonding parameters within the almost planar ligand molecules, mostly expressed in N—O-bond lengthening and endocyclic bond-angle widening at the nitrogen atoms. Additional supramolecular features are found in the crystal structure of 2 as two adjacent molecules form dimers via additional, weak O...Sn interactions.

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