Solution and solid-state studies of doubly trimethylene-bridged tetraalkyl p -phenylenediamine diradical dication conformations

Almaz S. Jalilov; Gaoquan Li; Stephen F. Nelsen; Ilia A. Guzei; Qin Wu

doi:10.1021/ja100322k

Solution and solid-state studies of doubly trimethylene-bridged tetraalkyl p -phenylenediamine diradical dication conformations

Almaz S. Jalilov, Gaoquan Li, Stephen F. Nelsen, Ilia A. Guzei, Qin Wu

Research output: Contribution to journal › Article › peer-review

21 Scopus citations

Abstract

X-ray crystallographic structures are reported for 1(Me) ²⁺(SbCl₆^-)₂a·2CH ₃CN, 2(Et)²⁺(SbF₆^-) ₂a·2CH₃CNa·2CH₂Cl₂, and 1(iPr)²⁺(SbF₆^-)₂, which also contained unresolved solvent and is in a completely different conformation than the methyl- and ethyl-substituted compounds. A quite different structure of 1(Me)²⁺(SbF₆^-)₂ than that previously published was obtained upon crystallizing it from a mixture rich in monocation. It does not contain close intramolecular PD⁺,PD⁺ contacts but has close intermolecular ones. Low temperature NMR spectra of 1(Me) ²⁺ and 1(Et)²⁺ in 2:1 CD₃OD/CD₃CN showed that both contain three conformations of all-gauche NCCC unit material with close intramolecular PD⁺,PD⁺ contacts. In addition to the both PD⁺ ring syn and anti material that had been seen in the crystal structure of 1(Me)²⁺(SbF₆^-) ₂a·2CH₃CN published previously, an unsymmetrical conformation having one PD⁺ ring syn and the other anti (abbreviated uns) was seen, and the relative amounts of these conformations were significantly different for 1(Me)²⁺ and 1(Et)²⁺. Calculations that correctly obtain the relative amounts of both the methyl- and ethyl-substituted material as well as changes in the optical spectra between 1(Me)²⁺ and 1(Et)²⁺, which contains much less of the uns conformation, are reported.

Original language	English
Pages (from-to)	6176-6182
Number of pages	7
Journal	Journal of the American Chemical Society
Volume	132
Issue number	17
DOIs	https://doi.org/10.1021/ja100322k
State	Published - 5 May 2010
Externally published	Yes

ASJC Scopus subject areas

Catalysis
General Chemistry
Biochemistry
Colloid and Surface Chemistry

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@article{03e7bb94f0594aaf80612a4b5d1d7fcc,

title = "Solution and solid-state studies of doubly trimethylene-bridged tetraalkyl p -phenylenediamine diradical dication conformations",

abstract = "X-ray crystallographic structures are reported for 1(Me) 2+(SbCl6-)2a·2CH 3CN, 2(Et)2+(SbF6-) 2a·2CH3CNa·2CH2Cl2, and 1(iPr)2+(SbF6-)2, which also contained unresolved solvent and is in a completely different conformation than the methyl- and ethyl-substituted compounds. A quite different structure of 1(Me)2+(SbF6-)2 than that previously published was obtained upon crystallizing it from a mixture rich in monocation. It does not contain close intramolecular PD+,PD+ contacts but has close intermolecular ones. Low temperature NMR spectra of 1(Me) 2+ and 1(Et)2+ in 2:1 CD3OD/CD3CN showed that both contain three conformations of all-gauche NCCC unit material with close intramolecular PD+,PD+ contacts. In addition to the both PD+ ring syn and anti material that had been seen in the crystal structure of 1(Me)2+(SbF6-) 2a·2CH3CN published previously, an unsymmetrical conformation having one PD+ ring syn and the other anti (abbreviated uns) was seen, and the relative amounts of these conformations were significantly different for 1(Me)2+ and 1(Et)2+. Calculations that correctly obtain the relative amounts of both the methyl- and ethyl-substituted material as well as changes in the optical spectra between 1(Me)2+ and 1(Et)2+, which contains much less of the uns conformation, are reported.",

author = "Jalilov, {Almaz S.} and Gaoquan Li and Nelsen, {Stephen F.} and Guzei, {Ilia A.} and Qin Wu",

year = "2010",

month = may,

day = "5",

doi = "10.1021/ja100322k",

language = "English",

volume = "132",

pages = "6176--6182",

journal = "Journal of the American Chemical Society",

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T1 - Solution and solid-state studies of doubly trimethylene-bridged tetraalkyl p -phenylenediamine diradical dication conformations

AU - Jalilov, Almaz S.

AU - Li, Gaoquan

AU - Nelsen, Stephen F.

AU - Guzei, Ilia A.

AU - Wu, Qin

PY - 2010/5/5

Y1 - 2010/5/5

N2 - X-ray crystallographic structures are reported for 1(Me) 2+(SbCl6-)2a·2CH 3CN, 2(Et)2+(SbF6-) 2a·2CH3CNa·2CH2Cl2, and 1(iPr)2+(SbF6-)2, which also contained unresolved solvent and is in a completely different conformation than the methyl- and ethyl-substituted compounds. A quite different structure of 1(Me)2+(SbF6-)2 than that previously published was obtained upon crystallizing it from a mixture rich in monocation. It does not contain close intramolecular PD+,PD+ contacts but has close intermolecular ones. Low temperature NMR spectra of 1(Me) 2+ and 1(Et)2+ in 2:1 CD3OD/CD3CN showed that both contain three conformations of all-gauche NCCC unit material with close intramolecular PD+,PD+ contacts. In addition to the both PD+ ring syn and anti material that had been seen in the crystal structure of 1(Me)2+(SbF6-) 2a·2CH3CN published previously, an unsymmetrical conformation having one PD+ ring syn and the other anti (abbreviated uns) was seen, and the relative amounts of these conformations were significantly different for 1(Me)2+ and 1(Et)2+. Calculations that correctly obtain the relative amounts of both the methyl- and ethyl-substituted material as well as changes in the optical spectra between 1(Me)2+ and 1(Et)2+, which contains much less of the uns conformation, are reported.

AB - X-ray crystallographic structures are reported for 1(Me) 2+(SbCl6-)2a·2CH 3CN, 2(Et)2+(SbF6-) 2a·2CH3CNa·2CH2Cl2, and 1(iPr)2+(SbF6-)2, which also contained unresolved solvent and is in a completely different conformation than the methyl- and ethyl-substituted compounds. A quite different structure of 1(Me)2+(SbF6-)2 than that previously published was obtained upon crystallizing it from a mixture rich in monocation. It does not contain close intramolecular PD+,PD+ contacts but has close intermolecular ones. Low temperature NMR spectra of 1(Me) 2+ and 1(Et)2+ in 2:1 CD3OD/CD3CN showed that both contain three conformations of all-gauche NCCC unit material with close intramolecular PD+,PD+ contacts. In addition to the both PD+ ring syn and anti material that had been seen in the crystal structure of 1(Me)2+(SbF6-) 2a·2CH3CN published previously, an unsymmetrical conformation having one PD+ ring syn and the other anti (abbreviated uns) was seen, and the relative amounts of these conformations were significantly different for 1(Me)2+ and 1(Et)2+. Calculations that correctly obtain the relative amounts of both the methyl- and ethyl-substituted material as well as changes in the optical spectra between 1(Me)2+ and 1(Et)2+, which contains much less of the uns conformation, are reported.

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Solution and solid-state studies of doubly trimethylene-bridged tetraalkyl p -phenylenediamine diradical dication conformations

Abstract

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