Solid-state and theoretical model structures of monolithiated (Organosulfonyl)acetonitriles and the characterization and reactivity of their geminated dilithio derivatives

K.W. Henderson, A.R. Kennedy, D.J. MacDougall, D. Shanks

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Two monolithiated (organosulfonyl)acetonitriles [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, have been synthesized and, in turn, characterized in the solid state by X-ray crystallography. The complexes form novel chain and sheet polymeric structures in preference to the more common (SO2Li)2 or Li2N2 ring dimers associated with lithiated sulfones or nitriles. The X-ray crystal structures of the parent ligands RSO2CH2CN, where R = Ph 5 or t-Bu 6, were also elucidated to allow a direct evaluation of the effects of metalation on the bonding within the complexes. Ab initio calculations at the HF/6-31G* level of theory support the view that the simple dimers are not formed due to the inflexibility of the ligand backbone, precluding chelation and consequently destabilizing these structures. In contrast, polymer formation allows the metal to bridge between separate ligands, eliminating the need for internal chelation. Both 1 and 2 contain 'naked' anions where there is no direct bond between the anionic C atoms and the metal centers. The anionic C atom in 2 is essentially planar, whereas in 1 this center is distinctly pyramidylized. Crystal structure and solution 1H and 13C NMR data, in combination with ab initio (HF/6-31G*) and density functional (B3LYP/6-31++G**) calculations on model systems, indicate that both the sulfonyl and the nitrile units of the ligands participate in delocalizing the charge of the anions throughout the SCCN linkage. In addition, the dilithiated salts [PhSO2CCNLi2·THF], 3, and [t-BuSO2CCNLi2·0.75THF], 4, have been prepared by the reaction of 2 equiv of MeLi with 5 or 6 in THF solution. Both complexes have been characterized by 1H and 13C NMR spectroscopy and found to be authentic geminal organodimetallic species, with the methylene group being doubly deprotonated. Complexes 3 and 4 react cleanly with excess MeI to form the dialkylated products PhSO2CMe2CN, 7, and t-BuSO2CMe2CN, 8, respectively, in a single step.
LanguageEnglish
Pages606-616
Number of pages10
JournalOrganometallics
Volume21
Issue number4
DOIs
Publication statusPublished - 18 Feb 2002

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Acetonitriles
Model structures
acetonitrile
reactivity
Ligands
Derivatives
solid state
Nitriles
ligands
chelation
nitriles
Chelation
Dimers
Anions
Crystal structure
Metals
dimers
anions
Atoms
nuclear magnetic resonance

Keywords

  • monolithiated
  • acetonitriles
  • synthesized
  • X-ray crystallography
  • polymeric structures
  • lithiated sulfones
  • nitriles
  • anions

Cite this

@article{2f6afd4dd80b42de8f9ac74dda01e0e4,
title = "Solid-state and theoretical model structures of monolithiated (Organosulfonyl)acetonitriles and the characterization and reactivity of their geminated dilithio derivatives",
abstract = "Two monolithiated (organosulfonyl)acetonitriles [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, have been synthesized and, in turn, characterized in the solid state by X-ray crystallography. The complexes form novel chain and sheet polymeric structures in preference to the more common (SO2Li)2 or Li2N2 ring dimers associated with lithiated sulfones or nitriles. The X-ray crystal structures of the parent ligands RSO2CH2CN, where R = Ph 5 or t-Bu 6, were also elucidated to allow a direct evaluation of the effects of metalation on the bonding within the complexes. Ab initio calculations at the HF/6-31G* level of theory support the view that the simple dimers are not formed due to the inflexibility of the ligand backbone, precluding chelation and consequently destabilizing these structures. In contrast, polymer formation allows the metal to bridge between separate ligands, eliminating the need for internal chelation. Both 1 and 2 contain 'naked' anions where there is no direct bond between the anionic C atoms and the metal centers. The anionic C atom in 2 is essentially planar, whereas in 1 this center is distinctly pyramidylized. Crystal structure and solution 1H and 13C NMR data, in combination with ab initio (HF/6-31G*) and density functional (B3LYP/6-31++G**) calculations on model systems, indicate that both the sulfonyl and the nitrile units of the ligands participate in delocalizing the charge of the anions throughout the SCCN linkage. In addition, the dilithiated salts [PhSO2CCNLi2·THF], 3, and [t-BuSO2CCNLi2·0.75THF], 4, have been prepared by the reaction of 2 equiv of MeLi with 5 or 6 in THF solution. Both complexes have been characterized by 1H and 13C NMR spectroscopy and found to be authentic geminal organodimetallic species, with the methylene group being doubly deprotonated. Complexes 3 and 4 react cleanly with excess MeI to form the dialkylated products PhSO2CMe2CN, 7, and t-BuSO2CMe2CN, 8, respectively, in a single step.",
keywords = "monolithiated, acetonitriles, synthesized, X-ray crystallography, polymeric structures, lithiated sulfones, nitriles, anions",
author = "K.W. Henderson and A.R. Kennedy and D.J. MacDougall and D. Shanks",
year = "2002",
month = "2",
day = "18",
doi = "10.1021/om0107845",
language = "English",
volume = "21",
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publisher = "American Chemical Society",
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Solid-state and theoretical model structures of monolithiated (Organosulfonyl)acetonitriles and the characterization and reactivity of their geminated dilithio derivatives. / Henderson, K.W.; Kennedy, A.R.; MacDougall, D.J.; Shanks, D.

In: Organometallics, Vol. 21, No. 4, 18.02.2002, p. 606-616.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Solid-state and theoretical model structures of monolithiated (Organosulfonyl)acetonitriles and the characterization and reactivity of their geminated dilithio derivatives

AU - Henderson, K.W.

AU - Kennedy, A.R.

AU - MacDougall, D.J.

AU - Shanks, D.

PY - 2002/2/18

Y1 - 2002/2/18

N2 - Two monolithiated (organosulfonyl)acetonitriles [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, have been synthesized and, in turn, characterized in the solid state by X-ray crystallography. The complexes form novel chain and sheet polymeric structures in preference to the more common (SO2Li)2 or Li2N2 ring dimers associated with lithiated sulfones or nitriles. The X-ray crystal structures of the parent ligands RSO2CH2CN, where R = Ph 5 or t-Bu 6, were also elucidated to allow a direct evaluation of the effects of metalation on the bonding within the complexes. Ab initio calculations at the HF/6-31G* level of theory support the view that the simple dimers are not formed due to the inflexibility of the ligand backbone, precluding chelation and consequently destabilizing these structures. In contrast, polymer formation allows the metal to bridge between separate ligands, eliminating the need for internal chelation. Both 1 and 2 contain 'naked' anions where there is no direct bond between the anionic C atoms and the metal centers. The anionic C atom in 2 is essentially planar, whereas in 1 this center is distinctly pyramidylized. Crystal structure and solution 1H and 13C NMR data, in combination with ab initio (HF/6-31G*) and density functional (B3LYP/6-31++G**) calculations on model systems, indicate that both the sulfonyl and the nitrile units of the ligands participate in delocalizing the charge of the anions throughout the SCCN linkage. In addition, the dilithiated salts [PhSO2CCNLi2·THF], 3, and [t-BuSO2CCNLi2·0.75THF], 4, have been prepared by the reaction of 2 equiv of MeLi with 5 or 6 in THF solution. Both complexes have been characterized by 1H and 13C NMR spectroscopy and found to be authentic geminal organodimetallic species, with the methylene group being doubly deprotonated. Complexes 3 and 4 react cleanly with excess MeI to form the dialkylated products PhSO2CMe2CN, 7, and t-BuSO2CMe2CN, 8, respectively, in a single step.

AB - Two monolithiated (organosulfonyl)acetonitriles [PhSO2CHCNLi·TMEDA], 1, and [t-BuSO2CHCNLi·THF], 2, have been synthesized and, in turn, characterized in the solid state by X-ray crystallography. The complexes form novel chain and sheet polymeric structures in preference to the more common (SO2Li)2 or Li2N2 ring dimers associated with lithiated sulfones or nitriles. The X-ray crystal structures of the parent ligands RSO2CH2CN, where R = Ph 5 or t-Bu 6, were also elucidated to allow a direct evaluation of the effects of metalation on the bonding within the complexes. Ab initio calculations at the HF/6-31G* level of theory support the view that the simple dimers are not formed due to the inflexibility of the ligand backbone, precluding chelation and consequently destabilizing these structures. In contrast, polymer formation allows the metal to bridge between separate ligands, eliminating the need for internal chelation. Both 1 and 2 contain 'naked' anions where there is no direct bond between the anionic C atoms and the metal centers. The anionic C atom in 2 is essentially planar, whereas in 1 this center is distinctly pyramidylized. Crystal structure and solution 1H and 13C NMR data, in combination with ab initio (HF/6-31G*) and density functional (B3LYP/6-31++G**) calculations on model systems, indicate that both the sulfonyl and the nitrile units of the ligands participate in delocalizing the charge of the anions throughout the SCCN linkage. In addition, the dilithiated salts [PhSO2CCNLi2·THF], 3, and [t-BuSO2CCNLi2·0.75THF], 4, have been prepared by the reaction of 2 equiv of MeLi with 5 or 6 in THF solution. Both complexes have been characterized by 1H and 13C NMR spectroscopy and found to be authentic geminal organodimetallic species, with the methylene group being doubly deprotonated. Complexes 3 and 4 react cleanly with excess MeI to form the dialkylated products PhSO2CMe2CN, 7, and t-BuSO2CMe2CN, 8, respectively, in a single step.

KW - monolithiated

KW - acetonitriles

KW - synthesized

KW - X-ray crystallography

KW - polymeric structures

KW - lithiated sulfones

KW - nitriles

KW - anions

UR - http://pubs.acs.org/cgi-bin/article.cgi/orgnd7/2002/21/i04/html/om0107845.html

UR - http://dx.doi.org/10.1021/om0107845

U2 - 10.1021/om0107845

DO - 10.1021/om0107845

M3 - Article

VL - 21

SP - 606

EP - 616

JO - Organometallics

T2 - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 4

ER -