Boere, Rene

Permanent URI for this collection

https://opus.uleth.ca/handle/10133/3778

Browse

Browsing Boere, Rene by Issue Date

Filter results by year or month
Now showing 1 - 20 of 74
  • Thumbnail Image
    Item
    Structure of an eight-membered CN4S3 ring with the shortest known transannual s...s contact
    (International Union of Crystallography, 1985) Boeré, René T.; Oakley, Richard T.; Cordes, A. Wallace
    7-tert-Butyl-3-chloro- 1,3,5,2,4,6,8-trithiatetrazocine, CsH9C1N4S 3, Mr= 256"8, tetragonal, P42/n, a = 17.856 (2), c = 6.646 (1) A, V = 2118.9 (8)/k 3, z=8, Dx= 1.61gcm -3, 2(MoKa)=0.71073A, # =8.9cm -1, F(000)=1056, T=294K, final R= 0.049 for 1201 reflections. The molecule has a folded butterfly structure, with almost planar SNCNS and SNSNS fragments, and the C1 atom is endo. The transannular S-S contact is 2.378 (2)A, the shortest such distance in any thiazyl compound.
  • Thumbnail Image
    Item
    Structure of a bicyclic sulfur-nitrogen-carbon heterocyclic molecule
    (International Union of Crystallography, 1985) Cordes, A. Wallace; Oakley, Richard T.; Boeré, René T.
    7-Phenyl- 124324b'2,524-trithia-2,4,6,8,9-penta - azabicyclo[3.3.1]nonane, CTHsNsS 3, M r = 255.3, monoclinic, P2Jn, a = 5.958 (1), b = 22.954 (2), c= 7.428 (1) A,/I= 106.25 (1) °, V= 975.2 (4) A 3, Z=4, D x = 1.74 g cm -3, 2(Mo K~) = 0.71073 A, /~ = 7.00 cm -l, F(000) = 520, T = 293 K, R = 0.030 for 1363 unique observed reflections. The planar SNCNS and SNSNS components of the bicyclic molecule make dihedral angles of 137.1 and 118.3 ° with the SNS bridging unit. The S-N bonds connecting the NSN fragment to the CN3S 2 ring are much longer (1.728 A) than those in the remainder of the molecule (1.546- 1.630 A).
  • Thumbnail Image
    Item
    Structure of 1,3-dichloro-5-phenyl-1λ4,3λ4,2,4,6-dithiatriazine
    (International Union of Crystallography, 1985) Graham, J. B.; Cordes, A. W.; Oakley, Richard T.; Boeré, René T.
    C7HsC12N3S2, Mr=266.17, triclinic, P], a=6-028(1), b=9-985(2), c=10.157 (3) /~, ct= 117.33 (2), fl= 106.73(2), y=90.31(1) °, V= 513-3(4)/~3, Z=2, D x=1.72gcm -3, 2(MoK~t)= 0.71073 A, /1 = 9.85 cm -1, F(000) = 268, T= 293 K, R = 0.032 for 1547 unique observed reflections. The SNCNS portion of the ring is planar within 0-060 (2)/~ and the third N is displaced 0.336 (2) A from this plane on the side opposite the S-bonded C1 atoms. The S-N distances range from 1.581 (1) to 1.615 (2)/~ and the N-C distances are 1.327 (2) and 1.344 (2) ./k.
  • Thumbnail Image
    Item
    Structure of an eight-membered CN4S3 ring with a Ph3P=N substituent
    (International Union of Crystallography, 1986) Boeré, René T.; Ferguson, George; Oakley, Richard T.
    7-Phenyl-3-(triphenylphosphinimino)- 1,3,5,- 2,4,6,8-trithiatetrazocine, C25H20N5PS3, Mr = 517.64, monoclinic, P21/c, a = 13.957 (3), b = 9.242 (3), c = 19.473 (4)/k, fl= 102.80 (2) °, V= 2449.4 A 3, Z =4, Dx=l.4Ogcm -3, 2(MoKc0=0.71069A, ~= 3.8cm -1, F(000)=1072, T=293(1) K, final R= 0.038 for 2430 observed reflections. The molecule has a phenyl ring substituted at a planar carbon, and a PhaP=N group substituted at S in the 3-position. The CN4S3 ring is folded by 114.5 °, with an almost planar SNCNS fragment, and an endo-S-envelope SNSNS fragment (dihedral 145.0°). The PhaP=N substituent at S is endo and the transannular S...S contact is 2.415 (1)A.
  • Thumbnail Image
    Item
    The structure of the norbornadiene adduct of 5-phenyl-1,3,2,4,6-dithiatriazine
    (International Union of Crystallography, 1986) Cordes, A. Wallace; Craig, S. L.; Privett, J. A. James; Oakley, Richard T.; Boeré, René T.
    10-Phenyl- 1,8-dithia-9,11,12-triazatetracyclo- [6.3.1.1 a,6.02,7]tfideca- 1 (11),4,9,8 (12)-tetraene, C ~4- H13N3S2, Mr-- 287.4, monoclinic, P2 l, a = 5-789 (2), b=10.064(1), c--11.109(2)A, fl=94.78(2) °, V = 644.9 (4)/~3, Z = 2, D x = 1.48 g cm -3, 2(Mo Kct) =0.71073/~, p-- 3.84cm -~, F(000)= 300, T-- 293 K, R -- 0.037 for 1203 unique observed reflections. The norbornadiene bonds to the sulfur atoms in the exo-fl orientation and the nitrogen atom between the sulfur atoms is displaced 0.802 (4)/~ from the SNCNS plane. The C-N bond lengths are equal [1.335 (5)A] and the S--N bond lengths in a very narrow range of values [1.637 (4)-1.652 (4) A].
  • Thumbnail Image
    Item
    3,7-Di-tert-butyl-1,5,2,4,6,8-dithiatetrazocine
    (International Union of Crystallography, 1995) Parvez, Masood; Boeré, René T.; Derrick, Sean; Moock, Klaus H.
    The eight-membered ring in the title compound, C10HI8N4S2, lies about an inversion centre and is essentially planar with normal bond lengths and angles [mean C--S 1.569 (2) and mean C--N 1.326 (3)A].
  • Thumbnail Image
    Item
    A dimer of 4-(4-methoxyphenyl)-1,2,3,5-diselenadiazole
    (International Union of Crystallography, 1995) Parvez, Masood; Boeré, René T.; Moock, Klaus H.
    The analysis of the title compound, C8H7N2OSe2, shows that its crystals are composed of weakly linked dimers, with intramolecular Se--Se distances of 2.343(3) and 2.345 (2)A,, intermolecular Se-.-Se distances of 3.193(3) and 3.316 (3) /k, and lateral Se...Se interactions of 3.514 (2) and 3.579 (3) A,.
  • Thumbnail Image
    Item
    Infrared diode laser spectroscopy of the CCO radical: the 2v1-v1 and v1+v3-v3 difference bands
    (AIP Publishing, 1998) Moazzen-Ahmadi, N.; Boeré, René T.
    The 2n 12n 1 and n 11n 32n 3 difference bands of the CCO radical in the gas phase have been studied using a tunable infrared diode laser spectrometer. The CCO radical was produced using a flowing mixture of carbon suboxide and helium subjected to a hollow-cathode discharge. The spectral region between 1920– 1960 cm21 was probed. Ninety and seventy-five rovibrational transitions were measured in the 2n 12n 1 and n 11n 32n 3 bands, respectively. The analyses of these bands yielded spectroscopic constants for the ~001!, ~200!, and ~101! vibrational states. The band origins for 2n 12n 1 and n 11n 32n 3 were determined to be 1941.85761(54) cm21 and 1936.79402(56) cm21, respectively.
  • Thumbnail Image
    Item
    Preparation and x-ray structure of 4-N,N'-bis(trimethylsilyl)- amino-3,5-diisopropylphenylselenium trichloride
    (Verlag der Zeitschrift für Naturforschung, 1999) Maaninen, Arto; Boeré, René T.; Chivers, Tristram; Parvez, Masood
    The reaction of SeCU or SeCF with /V,/V’-bis(trimethylsilyl)-2,6-diisopropylaniline occurs not at the nitrogen atom but by electrophilic aromatic substitution at C-4 of the phenyl ring to give [(CH3)3Si]2NC6H2('Pr:)SeCl3, which crystallizes as the chloro-bridged dimer in the triclinic system, space group Pi, a - 10.2598(17), b = 13.665(3), c = 9.7838(10) A, a = 90.056(13), ß = 102.439(11), 7 = 70.922(14)°, V = 1262.3(4) A \Z = 1. The dimer contains an essentially planar CUSe^-Cl^SeCU unit, with trans apical (Me3SihNC6H2('Pr)2 groups, resulting in approximately square pyramidal geometry at Se. The bridging Se-Cl distances are unequal at 2.587(2) and 2.749(2) A.
  • Thumbnail Image
    Item
    Electrochemistry of redox-active Group 15/16 heterocycles
    (Elsevier, 2000) Boeré, René T.; Roemmele, Tracey L.
    This review is a critical overview of the literature on electrochemistry of unsaturated ring compounds containing bonds between Group 15 and Group 16 elements (principally S and N), including metallacycles. It contains a detailed compilation of measured redox potentials and the conditions under which these were obtained for over 200 compounds. An introduction to the application of solution electrochemistry to this class of compounds is provided, and the relevance of such measurements to materials design is discussed.
  • Thumbnail Image
    Item
    The diversity of the stable and persistent phosphorus-containing radicals
    (American Chemical Society, 2005) Armstrong, A.; Chivers, T.; Boeré, René T.
    Stable and persistent phosphorus-containing radicals can be divided into five general categories: phosphinyl, diphosphanyl, 1,3-diphosphaallyl, lithiated tetrakisimidophosphates, and phosphaverdazyl systems. The syntheses, structures, EPR spectroscopic characterization, and sources of stability of these neutral radicals are presented and compared.
  • Thumbnail Image
    Item
    Synthesis, crystal structure and DFT calculations on 2,6-diisopropylphenylcopper: its use in the preparation of dichloro-2,6-diisopropylphenylphosphine
    (Elsevier, 2006) Boeré, René T.; Masuda, Jason D.; Tran, Peter
    The homoleptic aryl copper reagent [Cu4Dipp4] (Dipp = 2,6-diisopropylphenyl) has been prepared and structurally characterized by a single-crystal X-ray diffraction study. Its tetrameric structure differs in significant details from that of the previously reported [Cu4Tripp4] (Tripp = 2,4,6-triisopropylphenyl). The electronic structure of the cluster has been probed through B3LYP/6-3111G(2d,p)//B3LYP/6-31G calculations on [Cu4Ph4] constrained to D2d symmetry. The utility of the new copper reagent is demonstrated by the preparation of pure DippPCl2, for which the crystal structure is also reported.
  • Thumbnail Image
    Item
    Diethylmethyleniminium chloride
    (International Union of Crystallography, 2007) Boeré, René T.
    The title compound, C5H12N+·Cl-, contains [Et2N=CH2]+ and Cl- ions. The C=N double-bond distance is 1.2729 (13) Å and the sum of the angles around the central N atom is 359.92°. There are short contacts [2.973 (1) Å] between the iminium C atom and the Cl- ion and between five of the C-H H atoms and the Cl- ion, of which the shortest is 2.623 (11) Å.
  • Thumbnail Image
    Item
    (E)-1,2-Bis(3-bromo-4-methylphenyl)-ethene
    (International Union of Crystallography, 2008) Boeré, René T.; Robbins, Steven J.
  • Thumbnail Image
    Item
    1,3-Diphenylisobenzofuran
    (International Union of Crystallography, 2008) Boeré, René T.; Dibble, Peter W.; Fischer, Kristapher E.
  • Thumbnail Image
    Item
    Coupling of CpCr(CO)3 and heterocyclic dithiadiazolyl radicals: synthetic, X-ray diffraction, dynamic NMR, EPR, CV and DFT studies
    (ACS Publications, 2008) Lau, Hiu F.; Ang, Chwee Y.; Ng, Victor W. L.; Kuan, Seah L.; Goh, Lai Y.; Borisov, Alexey S.; Hazendonk, Paul; Roemmele, Tracey L.; Boeré, René T.; Webster, Richard D.
    The reaction of 1,2,3,5-dithiadiazolyls, (4-R-C6H4CN2S2)2 (R = Me, 2a; Cl, 2b; OMe, 2c; and CF3, 2d) and (3-NC-5-tBu-C6H3CN2S2)2 (2e) with (CpCr(CO)3]2 (Cp = η5-C5H5) (1) at ambient temperature, yielded respectively the complexes CpCr(CO)2(η2-S2N2CC6H4R) (R = 4-Me, 3a; 4Cl, 3b; 4-OMe, 3c; and 4-CF3, 3d) and CpCr(CO)2(η2-S2N2CC6H3-3-(CN)-5-(tBu)) (3e) in 35 – 72 % yields. The complexes 3c and 3d were also synthesized via a salt metathesis method from the reaction of NaCpCr(CO)3 (1B) and the 1,2,3,5-dithiadiazolium chlorides, 4-R-C6H4CN2S2Cl (R = OMe, 8c; CF3, 8d) with much lower yields of 6 and 20 %, respectively. The complexes were characterized spectroscopically, and also by single crystal X-ray diffraction analysis. Cyclic voltammetry experiments were conducted on 3a-e, EPR spectra were obtained of one-electron reduced forms of 3a-e, and variable temperature 1H NMR studies were carried out on complex 3d. Hybrid DFT calculations were performed on the model system [CpCr(CO)2S2N2CH] and comparisons are made with the reported CpCr(CO)2(π-allyl) complexes.
  • Thumbnail Image
    Item
    4-hydrazinopyridinium chloride
    (International Union of Crystallography, 2009) Boeré, René T.; Hassan, Mohammad R.
  • Thumbnail Image
    Item
    Electrochemical and chemical reduction of disulfur dinitride: formation of [S4N4], EPR spectroscopic characterization of the [S2N2H]• radical and X-ray structure of [Na(15 crown-5)][S3N3]
    (ACS Publications, 2009) Roemmele, Tracey L.; Konu, Jari; Boeré, René T.; Chivers, Tristram
    Voltammetric studies of S2N2 employing both cyclic voltammetry (CV) and rotating disc electrode (RDE) methods on GC electrodes at RT revealed two irreversible reduction processes at ca. −1.4 V and −2.2 V in CH3CN, CH2Cl2 and THF (vs. ferrocene) and no observable oxidation processes up to the solvent limit when the scan is initially anodic. However, after cycling the potential through −1.4 V, two new couples appear near −0.3 V and −1.0 V due to [S3N3]−/0 and [S4N4]−/0 respectively. The diffusion coefficient D for S2N2 was determined to be 9.13 × 10−6 cm2 s−1 in CH2Cl2 and 7.65 × 10−6 cm2 s−1 in CH3CN. Digital modeling of CVs fits well to a mechanism in which [S2N2]−• couples rapidly with S2N2 to form [S4N4]−•, which then decomposes to [S3N3]−. In situ EPR spectroelectrochemical studies of S2N2 in both CH2Cl2 and CH3CN resulted in the detection of strong EPR signals from [S4N4]−• when electrolysis is conducted at −1.4 V; at more negative voltages, spectra from transient adsorbed radicals are observed. In moist solvent or with added HBF4, a longer-lived spectrum is obtained due to the neutral radical [S2N2H]•, identified by simulation of the EPR spectrum and DFT calculations. The chemical reduction of S2N2 with Na[C10H8] or Na[Ph2CO] produces [Na(15-crown5)][S3N3], while reduction with cobaltocene gives [Cp2Co][S3N3]. The X-ray structure of the former reveals a strong interaction (Na···N = 2.388(5) Å) between the crown ether-encapsulated Na+ cation and one of the nitrogen atoms of the essentially planar six-membered cyclic anion [S3N3]−.
  • Thumbnail Image
    Item
    Butylbis[µ-4-(2,4,6-trimethylphenylamino)pent-3-en-2-onato][4-(2,4,6-trimethylphenylamino)pent-3-en-2-onato]dimagnesium
    (International Union of Crystallography, 2009) Boeré, René T.; Gietz, Twyla M.
  • Thumbnail Image
    Item
    (Z)-2,2,2-Trichloro-N2-cyanoacetamidine
    (International Union of Crystallography, 2009) Baker, A. Elizabeth; Boeré, René T.