Das Methylviologen-Radikalkation. Synthese, Kristallstruktur und ab initio-Rechnungen von N,N′-Dimethyl-4,4′ -bipyridinium-chlorid-dihydrat / The Methylviologen Radical Cation. Synthesis, Crystal Structure and ab initio Calculations of N,N′ -Dimethyl-4,4′ -bipyridinium Chloride Dihydrate

The title compound has been prepared by the reduction of N,N′-dimethyl-4,4′-bipyridinium dichloride with dilithium tritelluride in dimethylformamide solution. It forms deep blue crystal needles, which were characterized by a crystal structure determination. Space group Pna 21,Z = 8,3450 observed unique reflections, R = 0.045. Lattice dimensions at -70°C: a =1707.6(8), b = 2323.9(11), c = 664.6(3) pm. The N,N′-dimethyl-4,4′-bipyridinium radical cations are planar and form ion pairs in the lattice. The chloride ions together with the water molecules form an infinite network of hydrogen bridges along the crystallographic a-axis. The structural parameters of the radical cation are in excellent agreement with ab initio calculations.

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Cleavage of the radical cations of alkenes; 1-butene and 4,4-dimethyl-1-pentene. Ab initio calculations on the interaction between the allyl and alkyl radical and carbocation moieties

Canadian Journal of Chemistry ◽

10.1139/v91-202 ◽

1991 ◽

Vol 69 (9) ◽

pp. 1365-1375 ◽

Cited By ~ 14

Author(s):

Xinyao Du ◽

Donald R. Arnold ◽

Russell J. Boyd ◽

Zheng Shi

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Radical Cation ◽

Alkyl Radical ◽

Radical Cations ◽

Molecular Orbital Calculations ◽

Allyl Radical ◽

Allyl Cation ◽

Tert Butyl ◽

Carbon Carbon Bond

Carbon–carbon bond cleavage of the radical cations of 1-butene [Formula: see text] and 4,4-dimethyl-1-pentene [Formula: see text] will generate the allyl and alkyl radical and carbocation fragments. Alternative bonding arrangements between the allyl and methyl moieties in [Formula: see text] and between the allyl and tert-butyl moieties in [Formula: see text] possible metastable intermediates or transition states preceding complete separation of the fragments, have been investigated by ab initio molecular orbital calculations. Structures were fully optimized at the UHF/6-31G* or UHF/STO-3G levels, and some of the calculations on [Formula: see text] were expanded with single point MP2/6-31G*//UHF/6-31G* computations. The C4H8+ radical cation, having a structure similar to that of 1-butene, is more stable than the separated fragments: 183 kj mol−1 lower in energy than the sum of the energies of the allyl cation and the methyl radical, and 385 kJ mol−1 lower than the sum of the energies of an allyl radical and a methyl cation, at the MP2/6-31G* level. The corresponding values at the UHF/STO-3G level are 276 and 415 kj mol−1, respectively. There is less bonding interaction between the allyl and tert-butyl moieties in [Formula: see text] The summation of the energies of the allyl radical and tert-butyl cation is 123 kj mol−1 lower than the summation of the energies of the allyl cation and tert-butyl radical, and 115 kJ mol−1 higher in energy than the bonded radical cation [Formula: see text] at the UHF/STO-3G level. These calculated values are compared with thermochemical data and with experimental results on the cleavage of these, and related, radical cations. Key words: radical cation, cleavage, ab initio calculations, electron transfer, photochemistry.

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Structural Parameters and Internal Rotational Barriers of tert-Butylammonium Ion: AM1 and ab initio Calculations

Zeitschrift für Naturforschung A ◽

10.1515/zna-1992-1215 ◽

1992 ◽

Vol 47 (12) ◽

pp. 1255-1256

Author(s):

Hiroyuki Ishida ◽

Yoshihiro Kubozono ◽

Setsuo Kashino ◽

Ryuichi Ikeda

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Internal Rotation ◽

Barrier Height ◽

Structural Parameters ◽

Mo Calculations ◽

Ab Initio Mo Calculations ◽

Rotational Barriers ◽

Ab Initio Mo ◽

Internal Rotational Barriers

Semiempirical and ab initio MO calculations were performed to estimate the structural parameters of tert-butylammonium ion and its potential energies for the internal rotation of the CH3 and NH3+ groups. The barrier height for the rotation of NH3+ was found to be lower than for that of CH3 , corresponding to the C - N bond being longer than the C - C bond.

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Microwave, infrared, and Raman spectra, conformational stability, structural parameters, vibrational assignment, and ab initio calculations for 2-methylpropionyl fluoride

The Journal of Physical Chemistry ◽

10.1021/j100198a013 ◽

1992 ◽

Vol 96 (19) ◽

pp. 7547-7554 ◽

Cited By ~ 14

Author(s):

J. R. Durig ◽

G. A. Guirgis ◽

W. E. Brewer ◽

G. Baranovic

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Raman Spectra ◽

Structural Parameters ◽

Conformational Stability ◽

Infrared And Raman Spectra ◽

Vibrational Assignment

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Ab initio calculations on the ring opening of cyclopropane radical cation. Trimethylene radical cation is not a stable intermediate

Journal of the American Chemical Society ◽

10.1021/ja00219a011 ◽

1988 ◽

Vol 110 (11) ◽

pp. 3405-3412 ◽

Cited By ~ 39

Author(s):

Ping. Du ◽

David A. Hrovat ◽

Weston Thatcher. Borden

Keyword(s):

Ab Initio Calculations ◽

Ab Initio ◽

Radical Cation ◽

Ring Opening ◽

Stable Intermediate

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Synthesis, structure determination and characterization by UV–Vis and IR spectroscopy of bis(diisopropylammonium) cis-dichloridobis(oxalato-κ2 O 1,O 2)stannate(IV)

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989019006030 ◽

2019 ◽

Vol 75 (6) ◽

pp. 742-745

Author(s):

Bougar Sarr ◽

Abdou Mbaye ◽

Cheikh Abdoul Khadir Diop ◽

Mamadou Sidibe ◽

Yoann Rousselin

Keyword(s):

Crystal Structure ◽

Metal Ion ◽

Point Group ◽

Chain Structure ◽

Chloride Ions ◽

Group Symmetry ◽

Point Group Symmetry ◽

Chloride Dihydrate ◽

Distorted Octahedral Coordination ◽

Distorted Octahedral

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.

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