Medium-sized cyclophanes. Part 18. 5-tert-Butyl-8-substituted [2.2]metaparacyclophanes: preparation, X-Ray diffraction studies, and their treatment with Lewis acids in benzene

1992 ◽  
pp. 2675 ◽  
Author(s):  
Takehiko Yamato ◽  
Jun-ichi Matsumoto ◽  
Kiwamu Tokuhisa ◽  
Katsuya Tsuji ◽  
Kazuaki Suehiro ◽  
...  
Keyword(s):  
Lewis Acids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tert Butyl

Singly Charged λ6Si-Silicate Anions with an SiF5C Skeleton: Syntheses and Crystal Structure Analyses of the Ionic Hexacoordinate Silicon Compounds [Me3NH][F5SiCH2NMe2H]·H2O and [Me3NH][F5SiCH2NMe2H]·H2O

2000 ◽  
Vol 55 (1) ◽  
pp. 60-64
Author(s):  
Melanie Pülm ◽  
Joachim Becht ◽  
Reinhold Tacke
Keyword(s):  
Crystal Structure ◽  
Lewis Acids ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
Silicon Compounds ◽  
X Ray ◽  
Distorted Octahedra ◽  
Singly Charged ◽  
Crystalline Hydrates

The zwitterionic λ5Si-tetrafluorosilicates F4SiCH2NMe2H (1) and F4SiCH2NMe3 (2) behave as Lewis acids and react with [Me3NH]F (molar ratio 1:1) in aqueous solution to yield the ionic λ6Si-pentafluorosilicates [Me3NH][F5SiCH2NMe2H] (3) and [Me3NH][F5SiCH2NMe3] (4), respectively. These hexacoordinate silicon compounds contain singly charged λ6Si-silicate anions ([F5SiCH2NMe2H]- , [F5SiCH2NMe3]- ) with an SiF5C skeleton. Compounds 3 and 4 were isolated as the crystalline hydrates 3·H2O (yield 80%) and 4·H2O (yield 82%) which were structurally characterized by single-crystal X-ray diffraction. The Si-coordination polyhedra in the crystals of 3·H2O and 4·H2O are slightly distorted octahedra

Functionalisation of Imidazolin-2-imine to Corresponding Phosphinamine, Chalcogenide (O, S, Se, Te), and Borane Compounds

2015 ◽  
Vol 68 (1) ◽  
pp. 127 ◽  
Author(s):  
Kishor Naktode ◽  
Sayak Das Gupta ◽  
Abhinanda Kundu ◽  
Salil K. Jana ◽  
Hari Pada Nayek ◽  
...  
Keyword(s):  
Good Yield ◽  
Density Functional ◽  
Elemental Sulfur ◽  
Molecular Structures ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Tert Butyl ◽  
Imine Ligands ◽  
Orbital Analysis

1,3-Di-tert-butyl-imidazolin-2-ylidine-1,1-diphenylphosphinamine (2) was prepared from 1,3-di-tert-butyl-imidazolin-2-imine (1) and chlorodiphenylphosphine. Compound 2 was treated further with elemental sulfur, selenium, and tellurium to afford the corresponding chalcogenide derivatives, 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinothioicamide (4), 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinoselenoicamide (5), and 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinotelluroicamide (6) in good yield. 1,3-Di-tert-butyl-imidazolin-2-ylidine-P,P-diphenylphosphinicamide (3) was obtained by dissolving compound 2 in hydrochloric acid solution in THF. The corresponding borane adduct, 1,3-di-tert-butyl-imidazolin-2-ylidine-P,P-diphenyl-phosphinaminoborane (7) was isolated by the reaction of compound 2 and sodium borohydride in good yield. The molecular structures of compounds 2 and 4–7 were established by X-ray diffraction analyses. To analyse the electronic structure of chalcogenides of imidazolin-2-imine ligands, the protonation energies of the oxygen, sulfur, and selenide derivative of ligand 2 were calculated by means of density functional theory. Finally, the charge distribution in compounds 3, 4, and 5 were determined using natural bond orbital analysis.

Hydrido(acylenolato)cobalt(III)-Verbindungen mit Trimethylphosphan- Liganden: Insertionsreaktionen mit Alkinen und die ersten Carbonylcobalt(III)-Komplexe / Hydrido(acylenolato)cobalt(III) Compounds Containing Trimethylphosphane Ligands: Insertion Reactions with Alkynes and the First Carbonylcobalt(III) Complexes

2000 ◽  
Vol 55 (8) ◽  
pp. 707-717 ◽  
Author(s):  
Hans-Friedrich Klein ◽  
Xiaoyan Li ◽  
Ulrich Flörke ◽  
Hans-Jürgen Haupt
Keyword(s):  
Axial Position ◽  
Coupling Reactions ◽  
Carbonyl Complexes ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Insertion Reactions ◽  
X Ray ◽  
Reversible Transformation ◽  
Tert Butyl ◽  
Trigonal Bipyramidal

Abstract Formal insertion of phenylethyne into Co-H functions of mer-octahedral acyl(enolato)-cobalt(III) hydrides 1-3 proceeds under ambient conditions affording η1-vinylcobalt(III) compounds where the dianionic acyl(enolato) ligands are derived from 2-formyl-4-phenyl-cyclohexanone (4), 1-formyl-cyclohexan-2-one (5), and 3-hydroxo-2,3-diphenyl-propenal (6). Dissociation and association of trimethylphosphane results in a reversible transformation of penta-coordinate complexes 4 -6 into hexa-coordinate ones 7 -9, respectively, involving different tautomeric vinyl species. In toluene solution 9 rearranges by reductive C,C coupling into a 5,6-η2-olefin(enolato)cobalt(I) complex 10. Trimethylsilylethyne undergoes a hydrolytic desilylation reaction which is followed by reductive C,C-coupling reactions of acyl and vinyl functions selectively producing chelating η1-enolato-5,6-η2-olefin ligands in cobalt(I) com ­ pounds 13 -16 where the (ax,eq)chelating ligands are derived from 1-formyl-cyclohexan-2-one (13), 3-hydroxo-2,3-diphenyl-propenal (14), 2-formyl-α-tetralone (15), and 2-formyl-4-tert-butyl-cyclohexanone (16). An axial position of the enolato-O donor in the trigonal bipyramidal configuration of complex 15 has been confirmed by X-ray diffraction analysis. With 1,4-bis(trimethylsilyl)buta-diyne 1,2-addition in cobalt(III) hydrides 2, 3, 11 (as deriverd from 2-formyl-α-tetralone), and 12 (as derived from 2-formyl-4-tert-butyl-cyclohexanone) produces 2-metalated vinyl groups in compounds 17 -20. Dissociation of trimethylphosphane from 17 and 19 does not activate C,C coupling at the cobalt(III) centre of penta-coordinate 21 and 22. Steric congestion in compounds 17, 18, and 20 favours exchange of trimethylphosphine for carbon monoxide affording the first octahedral carbonyl complexes of cobalt (d6) (23 -25). In the crystal and in solution a meridional configuration is adopted by complex 23 with the CO group in a position opposite to the acyl function.

scholarly journals Reactions of Pentaphenylantimony and Penta-Para-Tolylanimony with Calixarene [4-t-BuC6H2OH(S-2)]4

2021 ◽  
Vol 13 (1) ◽  
pp. 47-57
Author(s):  
A.N. Efremov ◽  
◽  
V.V. Sharutin
Keyword(s):  
Hydrogen Bonds ◽  
Antimony Atom ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Deprotonated Form ◽  
X Ray ◽  
Bond Lengths ◽  
Tert Butyl ◽  
Average Value ◽  
Intramolecular Hydrogen

Pentaphenylantimony and penta-para-tolylantimony react with calixarene [4-t-BuC6H2OH(S-2)]4 (СArH) by way of arene elimination and formation of the [Ph4Sb]+[СAr]- × TolH (1), [p-Tol4Sb]+[CAr]- × H2O (2) ionic products with a yield up to 96%. The compound has been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction data, compounds 1 and 2 are ionic complexes with solvate molecules of toluene (1) and water (2). The cation has a tetrahedral coordination of the antimony atom with aryl ligands at the polyhedron vertices; the anion is represented by the deprotonated form of p-tert-butylthiacalix[4]arene. The three tert-butyl groups, the phenyl ring and solvated toluene in the structure of compound 1, and two tert-butyl fragments in the structure of compound 2 are disordered over two positions. The tetrahedral coordination of antimony atoms in the cations of compounds 1 and 2 is slightly distorted. The CSbC angles deviate from the theoretical value and vary within 106.0(4)−117.7(4)° (1), 105.75(15)−112.84(15)° (2). The average Sb–C bond lengths are 2.101(3) and 2.106(4) Å in structures 1 and 2, respectively. The [СAr]- anion is in the cone conformation, the upper rim of which is represented by the tert-butyl groups in the para-position, while the lower one is represented by hydroxy groups, one of which is deprotonated. The СAr–O– bond length (1.318(4) (1) and 1.326(4) (2) Å) is less than the average value of the СAr–OH bond lengths (1.338(4) (1) and 1.343(4) (2) Å), which indicates increasing multiplicity of the bond and localization of a negative charge on the oxygen atom. Intramolecular hydrogen bonds with the neiboring O atom are observed. The H∙∙∙O distances are 2.16, 1.69, 1.77 Å in 1 and 1.92, 1.79, 1.76 Å in 2. Dihedral angles between opposite phenoxide rings are 60.64° and 87.07° (1) and 83.85° and 80.42° (2), which indicates somewhat less symmetric anion in structure 1 than in structure 2. The formation of the crystal spatial structure is due to the formation of hydrogen bonds between ions with participation of oxygen and sulfur atoms, as well as СН∙∙∙π–interactions, while the ions form chains in the crystal of compound 1, and layers in the crystal of compound 2. Complete tables of atom coordinates, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 1850118 (1); No. 2013220 (2); [email protected] or http://www.ccdc.cam.ac.uk/data_request/cif).

scholarly journals Synthesis of Nitroxide Diradical Using a New Approach

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2701 ◽  
Author(s):  
Pavel Fedyushin ◽  
Tatyana Rybalova ◽  
Nargiz Asanbaeva ◽  
Elena Bagryanskaya ◽  
Alexey Dmitriev ◽  
...  
Keyword(s):  
Quantum Chemical ◽  
Total Yield ◽  
Exchange Interactions ◽  
Free Form ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Tert Butyl ◽  
Organic Systems

A new synthetic pathway to diradical organic systems is proposed. The effectiveness of this approach was exemplified by the synthesis of a new nitroxide diradical. An interaction of perfluorobiphenyl with lithium tert-butylamide, followed by oxidation of the thusly formed N4,N4′-di-tert-butyl-2,2′,3,3′,5,5′,6,6′-octafluorobiphenyl-4,4′-diamine with meta-chloroperoxybenzoic acid, led to the polyfluorinated nitroxide diradical, N,N′-(perfluorobiphenyl-4,4′-diyl)bis(N-tert-butyl(oxyl)amine), with a good total yield. The polyfluorinated diradical is stable and can be isolated in free form and completely characterized. The structure of the nitroxide diradical was proved by single-crystal X-ray diffraction analysis. According to the X-ray diffraction data, the diradical is considerably twisted: dihedral angles between the planes of the nitroxide groups and aromatic cycles are 65.1° and 69.5°, and between aromatic cycles 52.6°. Quantum chemical calculations predict well-balanced size of both intramolecular and intermolecular exchange interactions with J from −2.65 to −1.14 cm−1.

Die Kristallstruktur von Tricarbonyl(2.6-di-tert-butyl-pyridin)chrom(0) bei 200 K / Crystal Structure of Tricarbonyl(2,6-di/tert-butyl-pyridine)chromium(0) at 200 K

1984 ◽  
Vol 39 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Roland E. Schmidt ◽  
Werner Massa
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Pyridine Ring ◽  
Chromium Atom ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Tert Butyl

Based on single crystal X-ray diffraction data the crystal structure of tricarbonyl(2,6-dwmbutyl- pyridine)chromium(0) has been determined at 200 K: space group P 21/n, Z = 4, lattice constants a = 680.6(5), b - 1383.3(10), c = 1763.0(16) pm, β = 96.53(8)°, refinement to Rw - 0.048 for 1672 independent reflections with FO > 2 σ. The chromium atom is η6π6- bonded to the essentially planar pyridine ring (Cr-C: 219-222 pm, Cr-N: 221 pm). The CO ligands show “eclipsed” orientation with respect to the 2, 4 and 6 position of the pyridine ring. Two CO groups fit into the gaps formed by two methyl groups of the tert-butyl substituents in 2 and 6 position, respectively. The results are discussed in context with related arene and λ3-phosphorine complexes

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