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T.A. Michaels et al. / Journal of Organometallic Chemistry 889 (2019) 1e8
[PF6]) were purchased from Aldrich and used without further pu-
rification. Purification of CH2Cl2 and Et2O was performed using
methods similar to those previously described [100]. Tetrabuty-
lammonium hexafluorophosphate ([NBu4][PF6]) was purchased
from Aldrich and dried under vacuum at 100 ꢀC prior to use. (Z)-3-
Methylpent-2-en-4-yn-1-ol was purchased from Ark Pharm or
Arctom Chemicals. Propargyl ether, 5-(trimethylsilyl)4-pentyn-1-
ol, 4-pentyn-1-ol, 2-ethynylbenzyl alcohol and allyl phenyl ether
were purchased from Aldrich. All bis(phosphino)ferrocene ligands,
bis(triphenylphosphine)iminium chloride ([PPN]Cl), HAuCl4$H2O
4H, -C5H4), 2.18e1.06 (m, 44H), 2.17e1.52 (m, 24H, -C6H11),
1.39e1.05 (m, 20H, -C6H11). 31P{1H} NMR
(ppm): 43.4 (s).
d
3.2.2.4. [Au2(m d (ppm). 7.75 (s, 8H,
-Cl)(dtbpf)][BArF24]. 1H NMR
[BArF24]-), 7.51 (s, 4H, [BArF24]-), 4.67 (br s, 4H, -C5H4), 4.45 (br s,
4H, -C5H4), 1.38 (d, J ¼ 16.1 Hz, 36H, -CH3). 31P{1H} NMR
d (ppm):
72.0 (s).
3.2.2.5. [Au2(m d (ppm). 7.72 (s, 8H,
-Cl)(dppdtbpf)[BArF24]. 1H NMR
[BArF24]-), 7.62e7.48 (m, 14H, [BArF24]-), and -C6H5), 4.87 (br s, 2H,
-C5H4), 4.62 (br s, 2H, -C5H4), 4.48 (m, 2H, -C5H4), 4.44 (m, 2H,
and [Au2Cl2(m-dppe)] were purchased from Strem Chemical and
used without further purification. Potassium tetrakis(penta-
fluorophenylborate) (K[BArF20]) was purchased from Alfa Aesar. N-
(prop-2-yn-1-yl)benzamide was purchased from Enamine. The
gold compounds with bis(phosphino)ferrocene ligands (dppf [7],
-C5H4),1.35 (d, J ¼ 15.6 Hz,18H, -CH3). 31P{1H} NMR
d (ppm): 72.6 (s,
-PtBu2), 27.7 (s, -PPh2).
3.2.2.6. [Au2(m d (ppm). 7.70 (s, 8H,
-Cl)(dfurpf)[BArF24]. 1H NMR
dippf [59], dcpf [57], dtbpf [58] and dppdtbpf [60]), [Au2(
m-Cl)(m-
[BArF24]-), 7.51 (s, 4H, [BArF24]-), 6.92 (s, 4H, furanyl), 6.14 (s, 4H,
dtbpf)][BArF20 [61] and Na[BArF24
]
]
(BArF24 ¼ tetrakis-3,5-
furanyl), 4.61 (s, 4H, -C5H4), 4.42 (s, 4H, -C5H4), 2.39 (s, 12H, -CH3).
bis(trifluoromethyl)phenylborate) was prepared according to
literature methods [101]. NMR spectra were obtained in CDCl3 and
toluene-d8 using a Bruker Avance III HD 400 FT-NMR. The 1H and
13C{1H} NMR spectra were referenced using internal TMS and the
31P{1H} NMR spectra were referenced using external 85% H3PO4.
Elemental analysis was performed by Midwest Microlab.
31P{1H} NMR
d (ppm): 16.4 (s).
3.3. Electrochemistry procedure
All cyclic voltammetry experiments were conducted at room
temperature (21 1 ꢀC) using a CH Instruments Model CHI260D
potentiostat. Experiments were performed under an argon atmo-
sphere. Experiments were performed with analyte concentrations
of 1.0 mM in methylene chloride (10.0 mL) using 0.1 M [NBu4][PF6]
as the supporting electrolyte. A glassy carbon working electrode
3.2. General synthetic chemical procedures
3.2.1. [Au2Cl2(m-dfurpf)]
A solution of HAuCl4$H2O (0.1368 g, 0.364 mmol) in a mixture of
DI water (1 mL) and methanol (5 mL) was prepared and stirred at
0 ꢀC for 15 min. A solution of 2,20-dithioethanol (0.164 mL) in
methanol (1 mL) was added dropwise to the HAuCl4$H2O solution
and the resulting solution was stirred at 0 ꢀC for 15 min. A solution
of the dfurpf ligand (0.1038 g, 0.182 mmol) in a mixture of chloro-
form (7.5 mL) and methanol (3 mL) was added to the HAuCl4$H2O
solution and the reaction stirred overnight during which time the
solution was allowed to slowly warm to room temperature.
Methanol (20 mL) was then added to solution. The resulting solu-
tion was filtered and the remaining yellow solid was dried in vacuo
giving 0.1652 g (88% yield) of the product as a yellow solid. Single
(1.0 mm disk) that had been polished with 1.0 mm then 0.25 mm
diamond paste and rinsed with methylene chloride prior to use was
used as the working electrode. The experiments also employed a
platinum wire counter electrode and a nonaqueous Ag/AgCl
pseudo-reference electrode that was separated from the solution
by a frit. At the end of the experiments Ferrocene was added for use
as an internal reference. Data were background subtracted. Exper-
iments were conducted at scan rates of 100e1000 mV sꢁ1 in
100 mV sꢁ1 increments. All data are reported at a scan rate of
100 mV sꢁ1
.
3.4. X-ray diffraction studies
crystals of [Au2Cl2(
into a solution of the compound in CH2Cl2. Anal. Calcd for
30H28Au2Cl2FeO4P2: C, 34.81; H, 2.73. Found: C, 34.66; H, 2.86. 1H
NMR (CDCl3)
(ppm): 6.96 (t, J ¼ 3.18 Hz, 4H, furan-C3H), 6.11 (m,
4H, furan-C4H), 4.55 (m, 8H, -C5H4), 2.39 (s, 12H, -CH3). 13C{1H}
NMR (CDCl3)
(ppm): 160.0 (d, J ¼ 5.9 Hz, furan-C5), 141.5 (d,
J ¼ 96.0 Hz, furan-C2), 125.3 (d, J ¼ 24.8 Hz, furan-C3), 107.9 (d,
m-dfurpf)] were grown by vapor diffusion of Et2O
All operations were performed on a Bruker-AXS Kappa Apex II
CCD diffractometer with 0.71073 Å MoKa radiation. All diffrac-
tometer manipulations, including data collection, integration,
scaling, and absorption corrections were carried out using the
Bruker Apex2 software [102]. Unit cell parameters were obtained
C
d
d
from 60 data frames, 0.5ꢀ
f, from three different sections of the
J ¼ 9.3 Hz, furan-C4), 75.1 (d, J ¼ 16.1 Hz,
a
-C5H4), 74.7 (d,
Ewald sphere. Data collection was carried out at 100K, using a
frame time of 5 s and a detector distance of 51 mm. The optimized
strategy used for data collection consisted of two phi and six omega
scan sets, with 0.5ꢀ steps in phi or omega; completeness was 99.9%.
A total of 2882 frames were collected. Final cell constants were
obtained from the xyz centroids of 9824 reflections after
integration.
J ¼ 10.2 Hz,
b
-C5H4), 69.9 (d, J ¼ 82.9 Hz, ipso-C5H4), 14.2 (s, Me). 31
P
{1H} NMR (CDCl3)
d (ppm): 15.9 (s).
3.2.2. Characterization of [Au2(
The [Au2Cl2( -PP)] compounds (~10 mg, 0.10 mmol) and one
equivalent of Na[BArF24] were dissolved in ~1 mL CDCl3.
m-Cl)(PP)][BArF24] compounds
m
From the systematic absences, the observed metric constants
and intensity statistics, space group C2/c was chosen initially;
subsequent solution and refinement confirmed the correctness of
this choice. The structure was solved using SIR-92 [103], and refined
(full-matrix-least squares) using the Oxford University Crystals for
Windows program [104]. The asymmetric unit contains half a
molecule of the complex (Z ¼ 4; Z’ ¼ 1/2). All non-hydrogen atoms
were refined using anisotropic displacement parameters. After
location of H atoms on electron-density difference maps, the H
atoms were initially refined with soft restraints on the bond lengths
and angles to regularize their geometry (C—H in the range
0.93e0.98 Å and Uiso (H) in the range 1.2e1.5 times Ueq of the parent
3.2.2.1. [Au2(
m
-Cl)(dppf)[BArF24]. 1H NMR
d
(ppm). 7.72 (s, 8H,
-
[BArF24]-), 7.60e7.48 (m, 24H, [BArF24
]
and -C6H5), 4.48 (s, 4H,
-C5H4), 4.40 (s, 4H, -C5H4). 31P{1H} NMR
d
(ppm): 27.2 (s).
3.2.2.2. [Au2(m d (ppm). 7.70 (s, 8H,
-Cl)(dippf)][BArF24]. 1H NMR
[BArF24]-), 7.53 (s, 4H), 4.63 (br s, 4H, -C5H4), 4.43 (s, 4H, -C5H4), 2.33
(m, 4H, -CHMe2), 1.24 (dd, J ¼ 17.4, 7.0 Hz, 6H, -CH3), 1.20 (dd,
J ¼ 10.7, 7.0 Hz, 6H, -CH3). 31P{1H} NMR
d (ppm): 52.1 (s).
3.2.2.3. [Au2(
[BArF24]-), 7.52 (s, 4H, [BArF24]-), 4.60 (br s, 4H, -C5H4), 4.41 (br s,
m d (ppm). 7.70 (s, 8H,
-Cl)(dcpf)][BArF24]. 1H NMR
Michaels, Toni A.
