0000000000055627
AUTHOR
René T. Boeré
Mono‐ and Bis(imidazolidinium ethynyl) Cations and Reduction of the Latter To Give an Extended Bis‐1,4‐([3]Cumulene)‐p-carboquinoid System
An extended π-system containing two [3]cumulene fragments separated by a p-carboquinoid and stabilized by two capping N-heterocyclic carbenes (NHCs) has been prepared. Mono- and bis(imidazolidinium ethynyl) cations have also been synthesized from the reaction of an NHC with phenylethynyl bromide or 1,4-bis(bromoethynyl)benzene. Cyclic voltammetry coupled with synthetic and structural studies showed that the dication is readily reduced to a neutral, singlet bis-1,4-([3]cumulene)-p-carboquinoid as a result of the π-accepting properties of the capping NHCs. peerReviewed
The first unpaired electron placed inside a C3-symmetry P-chirogenic cluster
The Pd(3)(dppm*)(3)(CO)(n+) enantiomers (n = 2 (2), 1 (3)) were prepared either from (R,R)- or (S,S)-P-chirogenic bis(phenyl-m-xylylphosphino)methane (dppm*; 1) and Pd(OAc)(2) in the presence of CF(3)CO(2)H, CO and water (n = 2), and then by reductive electrolysis (n = 1). The stable enantiomeric [Pd(3)((S,S)-dppm*)(3)(CO)](+)˙ (3), is the first C(3)-symmetry radical-cation M-M bonded cluster, therefore the odd electron is delocalized onto the Pd(3) frame within this symmetry. The novel chiral species have been characterized by circular dichroism (CD) of both enantiomers of the Pd(3)(dppm*)(3)(CO)(2+) clusters (2) and by EPR spectroscopy for the Pd(3)((S,S)-dppm*)(3)(CO)(+)˙ paramagnetic co…
Electrochemical and Electronic Structure Investigations of the [S3N3]• Radical and Kinetic Modeling of the [S4N4]n/[S3N3]n (n = 0, −1) Interconversion
Voltammetric studies of S4N4 employing both cyclic (CV) and rotating disk (RDE) methods in CH2Cl2 at a glassy carbon electrode reveal a one-electron reduction at −1.00 V (versus ferrocene/ferrocenium), which produces a second redox couple at −0.33 V, confirmed to be the electrochemically generated [S3N3]− by CV studies on its salts. Diffusion coefficients (CH2Cl2/0.4 M [nBu4N][PF6]) estimated by RDE methods: S4N4, 1.17 × 10−5 cm2 s−1; [S3N3]−, 4.00 × 10−6 cm2 s−1. Digital simulations of the CVs detected slow rates of electron transfer for both couples and allowed for a determination of rate constants for homogeneous chemical reaction steps subsequent to electron transfer. The common paramet…
Structures and EPR spectra of binary sulfur–nitrogen radicals from DFT calculations
Abstract The scattered electron paramagnetic resonance (EPR) spectroscopic data for binary sulfur–nitrogen (S,N) radicals have been compiled and critically assessed.Many of these are inorganic rings or cages.For each species, possible equilibrium structures in the gas phase and the EPR hyperfine coupling (hfc) constants have been calculated with DFT using the B3LYP functional and basis sets of triple-ζ (or better) quality.Good agreement is obtained between calculated and measured values for the well characterized [S3N2]+ , a planar π-radical for which the s-component of the orbitals is likely to be reasonably independent of minor geometrical changes between gas-phase and condensed-phase sta…
Computational modeling of isotropic electron paramagnetic resonance spectra of doublet state main group radicals
The combined use of theoretical and mathematical methods in the analysis of electron paramagnetic resonance data has greatly increased the ability to interpret even the most complex spectra reported for doublet state inorganic main group radicals. This personal account summarizes the theoretical basis of such an approach and provides an in-depth discussion of some recent illustrative examples of the utilization of this methodology in practical applications. The emphasis is on displaying the enormous potential embodied within the approach. peerReviewed
Mono‐ and Bis(imidazolidinium ethynyl) Cations and Reduction of the Latter To Give an Extended Bis‐1,4‐([3]Cumulene)‐ p ‐carboquinoid System
An extended π-system containing two [3]cumulene fragments separated by a p-carboquinoid and stabilized by two capping N-heterocyclic carbenes (NHCs) has been prepared. Mono- and bis(imidazolidinium ethynyl) cations have also been synthesized from the reaction of an NHC with phenylethynyl bromide or 1,4-bis(bromoethynyl)benzene. Cyclic voltammetry coupled with synthetic and structural studies showed that the dication is readily reduced to a neutral, singlet bis-1,4-([3]cumulene)-p-carboquinoid as a result of the π-accepting properties of the capping NHCs.
Group 13 complexes of dipyridylmethane, a forgotten ligand in coordination chemistry.
The reactions of dipyridylmethane (dpma) with group 13 trichlorides were investigated in 1 : 1 and 1 : 2 molar ratios using NMR spectroscopy and X-ray crystallography. With 1 : 1 stoichiometry and Et2O as solvent, reactions employing AlCl3 or GaCl3 gave mixtures of products with the salt [(dpma)2MCl2](+)[MCl4](-) (M = Al, Ga) as the main species. The corresponding reactions in 1 : 2 molar ratio gave similar mixtures but with [(dpma)MCl2](+)[MCl4](-) as the primary product. Pure salts [(dpma)AlCl2](+)[Cl](-) and [(dpma)AlCl2](+)[AlCl4](-) could be obtained by performing the reactions in CH3CN. In the case of InCl3, a neutral monoadduct (dpma)InCl3 formed regardless of the stoichiometry emplo…
CCDC 1549500: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1414953: Experimental Crystal Structure Determination
Related Article: Petra Vasko, Virva Kinnunen, Jani O. Moilanen, Tracey L. Roemmele, René T. Boeré, Jari Konu, Heikki M. Tuononen|2015|Dalton Trans.|44|18247|doi:10.1039/C5DT02830B
CCDC 1414956: Experimental Crystal Structure Determination
Related Article: Petra Vasko, Virva Kinnunen, Jani O. Moilanen, Tracey L. Roemmele, René T. Boeré, Jari Konu, Heikki M. Tuononen|2015|Dalton Trans.|44|18247|doi:10.1039/C5DT02830B
CCDC 1549501: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1549502: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1414952: Experimental Crystal Structure Determination
Related Article: Petra Vasko, Virva Kinnunen, Jani O. Moilanen, Tracey L. Roemmele, René T. Boeré, Jari Konu, Heikki M. Tuononen|2015|Dalton Trans.|44|18247|doi:10.1039/C5DT02830B
CCDC 1549499: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1414955: Experimental Crystal Structure Determination
Related Article: Petra Vasko, Virva Kinnunen, Jani O. Moilanen, Tracey L. Roemmele, René T. Boeré, Jari Konu, Heikki M. Tuononen|2015|Dalton Trans.|44|18247|doi:10.1039/C5DT02830B
CCDC 1549503: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1414954: Experimental Crystal Structure Determination
Related Article: Petra Vasko, Virva Kinnunen, Jani O. Moilanen, Tracey L. Roemmele, René T. Boeré, Jari Konu, Heikki M. Tuononen|2015|Dalton Trans.|44|18247|doi:10.1039/C5DT02830B
CCDC 1549498: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031
CCDC 1549504: Experimental Crystal Structure Determination
Related Article: Brian M. Barry, R. Graeme Soper, Juha Hurmalainen, Akseli Mansikkamäki, Katherine N. Robertson, William L. McClennan, Alex J. Veinot, Tracey L. Roemmele, Ulrike Werner-Zwanziger, René T. Boeré, Heikki M. Tuononen, Jason A. C. Clyburne, Jason D. Masuda|2018|Angew.Chem.,Int.Ed.|57|749|doi:10.1002/anie.201711031