Beilstein J. Org. Chem. 2016, 12, 1566–1572.
berg or bought directly from Acros Organics, Fisher Scientific, After cooling to room temperature, the resulting solid was
Sigma Aldrich, Strem Chemicals, and TCI. Anhydrous solvents suspended in ethanol (2 mL) and the mixture was filtered. The
were taken from an MBraun MB SCS-800 solvent purification solid residue was washed with ethanol (3 × 2 mL) and diethyl
system containing appropriate drying agents. Deuterated sol- ether (3 × 3 mL) and dried in vacuo to give the beige product 1a
vents for the use of NMR spectroscopy were obtained from (1.05 g, 2.53 mmol, 86%). 1H NMR (400.33 MHz, DMSO-d6,
Deutero GmbH and Euriso-Top.
300.0 K) δ 9.90 (s, 2H, NCHS), 5.04 (s, 4H, CH2), 2.52 (s, 6H,
NCCH3), 2.47 (s, 6H, SCCH3) ppm; 13C{1H} NMR (100.66
1
H NMR spectra were recorded at room temperature and the MHz, DMSO-d6, 295.0 K) δ 157.1 (NCHS), 141.9 (NCCH3),
following instruments were employed: Bruker ARX-250 133.7 (SCCH3), 50.6 (CH2), 12.1 (NCCH3), 11.1 (SCCH3)
250 MHz), Bruker Avance 300 (300 MHz), Bruker Avance ppm; elemental analysis calculated: C, 34.80; H, 4.38; N, 6.76;
00 (400 MHz), Bruker Avance 500 (500 MHz). Chemical found: C, 34.69; H, 4.63; N, 6.64; HRMS (ESI+, DMSO/
(
4
shifts δ are indicated in ppm and were determined by reference MeOH) m/z (%): 253.0827 (100.0) [M – H − 2Br]+, 352.9222
to the residual 1H solvent peaks (acetone: 2.05 ppm; chloro- (41.3), 746.9344 (35.0) [2 M(79Br) − Br]+, calculated for [M –
form: 7.26 ppm; dichloromethane: 5.32 ppm; DMSO: H − 2Br]+: 253.0833, found: 253.0827; IR (ATR) ν = 3400 (w,
2
.50 ppm). Coupling constants J are given in Hz. The following br), 3070 (s), 2970 (s), 1738 (m), 1583 (s), 1443 (s), 1405 (s),
abbreviations describe the observed multiplicities: s = singlet, 1189 (s), 798 (s) cm−1; mp 255 °C dec.
d = doublet, t = triplet, q = quartet, quin = quintet, sext = sextet,
sept = septet, m = multiplet (composed abbreviations refer to 3,3'-(Ethane-1,2-diyl)bis(4,5-dimethylthiazolium)
multiple coupling patterns with the first letter indicating the bis(hexafluorophosphate) (1b)
greater coupling constant). 13C{1H} NMR spectra were re- 1.00 equiv 3,3'-(ethane-1,2-diyl)bis(4,5-dimethylthiazolium)
corded at room temperature with the following spectrometers: dibromide (1a, 1.50 g, 3.62 mmol) was dissolved in 75 mL
Bruker Avance 300 (75 MHz) and Bruker Avance 500 H2O. The solution was added slowly to aqueous 55% hexafluo-
(
125 MHz). The spectra were calibrated with respect to the sol- rophosphoric acid (3.00 equiv, 2.88 g, 10.9 mmol) in 50 mL
vent (acetone: 29.84 ppm, 206.26 ppm; chloroform: 77.16 ppm; H2O. The mixture was stirred at room temperature for 3 h. The
dichloromethane: 53.84 ppm; DMSO: 39.52 ppm). For process- formed precipitate was filtered and washed with water
ing, analysis and interpretation of NMR spectra, the program (3 × 25 mL) and diethyl ether (5 × 20 mL). It was dried in
TopSpin 3.2 by Bruker was used. All observed signals are vacuo to give the colourless product 1b (1.50 g, 2.75 mmol,
singlets. Elemental analyses were carried out in the Department 76%). Single crystals of salt 1b that were suitable for an X-ray
of Chemistry at the University of Heidelberg on the instru- structure analysis were obtained from acetone/diethyl ether.
ments vario EL and vario MICRO cube by Elementar Analy- 1H NMR (400.33 MHz, acetone-d6, 295.0 K) δ 9.88 (s, 2H,
sensysteme GmbH. Infrared spectra were recorded on a Bruker NCHS), 5.42 (s, 4H, CH2), 2.68 (s, 6H, NCCH3), 2.66 (s, 6H,
Lumos instrument with a Germanium ATR-crystal. The posi- SCCH3) ppm; 13C{1H} NMR (100.66 MHz, acetone-d6,
tions of the peaks are indicated in wavenumbers ν in cm–1. The 295.0 K) δ 157.1 (NCHS), 143.7 (NCCH3), 136.1 (SCCH3),
following abbreviations were used to describe both the intensi- 52.4 (CH2), 12.6 (NCCH3), 11.6 (SCCH3) ppm; elemental anal-
ty and profile of the signals: w (weak), m (medium), s (strong), ysis calculated: C, 26.48; H, 3.33; N, 5.15; found: C, 26.50; H,
br (broad). Mass spectra were recorded by the Mass Spectrome- 3.34; N, 5.37; HRMS (ESI+, CH2Cl2/MeOH) m/z (%):
try Service Facility of the Organic-Chemical Department of the 253.0828 (14.0) [M – H − 2PF6]+, 399.0548 (100.0) [M −
University of Heidelberg using the following instruments: PF6]+, 683.1201 (15.7), 943.0741 (73.0) [2 M − PF6]+; calcu-
Vacuum Generators ZAB-2F, Finnigan MAT TSQ 700, JEOL lated for [M − PF6]+: 399.0548, found: 399.0548; IR (ATR) ν =
JMS-700, Bruker ICR Apex-Qe hybrid 9.4 T FT-ICR. In 3132 (w), 1739 (w), 1595 (w), 1453 (w), 1211 (w), 828 (s), 740
general the ionization method was specified. Apart from the (w) cm−1; mp 220 °C dec.
method of ionization and the peak of the molecular ion, the base
peak and characteristic fragmentation peaks with their relative μ-Acetato-κO,κO'-μ-[3,3'-(ethane-1,2-diyl)bis(4,5-
intensities are reported.
dimethylthiazol-2-ylidene)]-κC,κC'-dicopper(I)
hexafluorophosphate (2)
Syntheses
A Schlenk flask flushed with argon was charged with 3,3'-
(ethane-1,2-diyl)bis(4,5-dimethylthiazolium) bis(hexafluoro-
phosphate) (1b, 0,10 g, 0.18 mmol, 1.00 equiv) and anhydrous
3,3'-(Ethane-1,2-diyl)bis(4,5-dimethylthiazolium)
dibromide (1a)
A Schlenk flask was charged with 3.00 equiv 4,5-dimethylthia- sodium acetate (0.04 g, 0.42 mmol, 2.30 equiv). The reaction
zole (1.00 g, 8.84 mmol) and 1.00 equiv 1,2-dibromoethane mixture was stirred under reduced pressure overnight. In a
(
0.55 g, 2.95 mmol). The mixture was stirred at 115 °C for 3 d. glove box, copper(I) acetate (0.05 g, 0.40 mmol, 2.20 equiv)
1570