1
oxyphenyldiphenylphosphine (POMe),30 2-ethoxyphenyldi-
phenylphosphine (POEt),31 2-methoxyethyldiphenylphosphine
(PC2OMe)32 were prepared using literature methods. Complex
1 was available from previous studies.1
PF6). H NMR (400 MHz, 25 ЊC, CD2Cl2): δ 8.66 (d, J = 8.20
Hz, H), 8.62 (d, J = 7.97 Hz, 1H), 8.51 (d, J = 5.12 Hz, 1H),
8.38–8.34 (m, 2H), 8.27 (d, J = 5.52 Hz, 1H), 8.11–8.05 (m, 2H),
8.00–7.96 (m, 2H), 7.84–7.76 (m, 3H), 7.59–7.40 (m, 8H), 7.16–
7.03 (m, 3H), 6.92–6.88 (m, 2H), 6.73 (dd, J1 = 5.49, J2 = 5.60
Hz, 1H), 6.65–6.56 (m, 3H). Elemental analysis: calc. for
C38H30F6N4OP2Ru: C, 54.62; H, 3.62; N, 6.70; found: C, 54.37;
H, 3.73; N, 6.72%. E1/2(RuIII/II) = 0.63 V vs. SCE.
NMR spectra were acquired on Bruker AC-200, Avance 300,
Avance 400, AM-400, AMX-500 or Varian XL-300 instruments,
1
using residual solvent peaks as internal H reference (vs. TMS
at δ 0) and 85% H3PO4 as external 31P reference (δ 0).
Electrochemical measurements were performed with a Pine
Instruments AFCBP1 bipotentiostat using a three-electrode
cell (Pt disc working electrode, Pt wire coil counter electrode,
Ag wire reference electrode). Decamethylferrocene or ferrocene
was used as internal standard. Experiments were done in
CH2Cl2 solution containing ≈0.1 M n-Bu4NPF6 supporting
electrolyte. Methylene chloride was distilled from calcium
hydride immediately before use in electrochemical experiments.
n-Bu4NPF6 was recrystallized three times from methanol, dried
in vacuo at 110 ЊC for 3 days, and stored in a dessicator.
[Ru(bpy)2(PC2OMe-P)2](PF6)2 5. To a solution of [Ru-
(bpy)2(Me2CO)2](BF4)2 (0.496 mmol) in N2-sparged acetone
(65 mL) was added 2 equivalents of 2-methoxyethyldiphenyl-
phosphine (0.249 g, 1.02 mmol) as a solution in N2-sparged
acetone (35 mL). The mixture was heated to reflux for 3 days,
then the clear red solution was filtered through Celite and
evaporated to dryness. The residue was converted to the PF6
salt and the bisphosphine complex was isolated by recrystalliz-
ation from acetone to yield a bright orange powder. Purified
by crystallization from methanol–acetone. Yield: ca. 35% by
31P{1H} NMR spectroscopy of the crude product mixture,
remainder bidentate P,O complex and other unidentified
products. 31P{1H} NMR (81 MHz, 25 ЊC, CD3CN): δ 22.0 (s,
PC2OMe), Ϫ144 (septet, JPF = 711 Hz, PF6). H NMR (200
MHz, 25 ЊC, CD3CN): δ 8.84 (d, J = 5.46 Hz, 4H), 7.99 (t,
J = 7.73 Hz, 4H), 7.87 (d, J = 7.90 Hz, 4H), 7.56 (dd, J1 = 5.96,
J2 = 7.38 Hz, 4H), 7.26 (dd, J1 = 7.34, J2 = 7.89 Hz, 4H), 6.98
(dd, J1 = 7.82, J2 = 7.38 Hz, 8H), 6.41 (m, 8H), 2.75 (s, 6H,
MeO), 2.69 (m, 4H), 1.71 (dd, J1 = 7.27, J2 = 6.82 Hz, 4H).
Elemental analysis: calc. for C50H50F12N4O2P4Ru: C, 50.39;
H, 4.23; N, 4.70; found: C, 50.58; H, 4.33; N, 4.75%.
E1/2(RuIII/II) = 1.60 V vs. SCE.
Preparation of complexes
[Ru(bpy)2(POEt-P,O)](PF6)2 2. Prepared as described for 3
(below) using 2-ethoxyphenyldiphenylphosphine and obtained
pure after metathesis to the PF6 salt (yield 85%). 31P{1H} NMR
(81 MHz, 25 ЊC, CD2Cl2): δ 51.1 (s, POEt), Ϫ144 (septet,
1JPF = 711 Hz, PF6). 1H NMR (200 MHz, 25 ЊC, CD2Cl2):
δ 8.61–8.54 (m, 2H), 8.31 (d, J = 5.6 Hz, 1H), 8.22–8.08 (m,
3H), 7.96–7.35 (m, 18H), 7.26–7.12 (m, 2H), 6.97–6.88 (m, 2H),
6.42–6.33 (m, 2H), 4.64–4.47 (m, 1H), 4.14–3.97 (m, 1H),
0.72 (t, J = 7.0 Hz, 3H). Elemental analysis: calc. for C40H35F12-
N4OP3Ru: C, 47.58; H, 3.49; N, 5.55; found: C, 47.32; H, 3.58;
N, 5.49%. Eox(RuIII/II) = 1.59 V vs. SCE. Crystals suitable for
X-ray crystallographic analysis were obtained by slow crystal-
lization from methanol.
1
1
Structure determination
Suitable crystals of 1–3 grown from methanol were selected and
mounted on thin glass fibres. Data were collected at 173(1) K on
a Rigaku/ADSC CCD area detector in two sets of scans
(ꢀ = 0.0 to 190.0Њ, χ = Ϫ90.0Њ; and ω = Ϫ18.0 to 23.0Њ,
χ = Ϫ90.0Њ) using 0.50Њ oscillations with 19.0, 12.0 and 77.0
second exposures, respectively. ORTEP representations of the
solid-state molecular structures of 1–3 were prepared using
Ortep-3 for Windows.33
Complex 2 crystallizes with two salt moieties, related by a
pseudo-inversion centre, in the asymmetric unit. This pseudo-
inversion centre is located at 0.8756 0.0228 0.8735, or roughly
x = 7/8, y = 0. The existence of pseudo-centres in non-
centrosymmetric structures has been studied in detail by
Marsh et al.34 and usually results in large correlations between
refined parameters of each crystallographically independent
moiety. In order to obtain reasonable anisotropic displacement
parameters, refinements were carried out using restraints that
called for equivalent anisotropic displacement parameters for
pairs of atoms related by the pseudo-inversion centre.
[Ru(bpy)2(PC2OMe-P,O)](PF6)2 3. A suspension of Ru-
(bpy)2Cl2ؒ2H2O (0.682 g, 1.31 mmol) in nitrogen-sparged
acetone (20 mL) was treated with a solution of AgBF4 (0.510 g,
2.62 mmol) in acetone (30 mL). The mixture was sparged
thoroughly with nitrogen, stirred at room temperature for
several hours to ensure complete precipitation of AgCl, then
filtered through Celite to yield a deep wine-red solution of
the solvate complex. To this solution was added 1 equivalent of
2-methoxyethyldiphenylphosphine (0.320 g, 1.31 mmol) as a
solution in acetone (20 mL), and the mixture was heated
to reflux under nitrogen overnight to yield a reddish orange
solution. The cooled reaction mixture was filtered, evaporated
to dryness and the residue dissolved in a small volume of
acetone and precipitated with aqueous NH4PF6. The flocculent
orange solid was collected, washed with water and ether, and
dried. Crude yield: 85%. Impurities (ca. 10% by 31P NMR)
removed by recrystallization from hot methanol. 31P{1H} NMR
(81 MHz, 25 ЊC, CD2Cl2): δ 50.5 (s, PC2OMe), Ϫ144 (septet,
1JPF = 711 Hz, PF6). 1H NMR (200 MHz, 25 ЊC, CD2Cl2): δ 8.80
(d, J = 5.69 Hz, 1H), 8.59–8.50 (m, 3H), 8.23–7.77 (m, 7H),
7.75–7.32 (m, 10H), 7.19–7.12 (m, 1H), 6.99–6.91 (m, 2H),
6.53–6.45 (m, 2H), 4.46–4.26 (m, 1H), 3.91–3.72 (m, 1H), 3.25–
2.85 (m, 2H), 2.97 (s, 3H, OCH3). Elemental analysis: calc. for
C35H32F12N4OP3Ru: C, 44.36; H, 3.51; N, 5.91; found: C, 44.00;
H, 3.63; N, 5.86%. E1/2(RuIII/II) = 1.48 V vs. SCE. Crystals
suitable for X-ray crystallographic analysis were obtained by
crystallization from hot methanol.
Complex 3 crystallizes in the non-centrosymmetric space
group P212121. A parallel refinement was carried out on both
enantiomers. The enantiomer reported herein was assigned on
the basis of the better final residual values.
CCDC reference numbers 153809–153811.
lographic data in CIF or other electronic format.
Acknowledgements
We thank the Natural Sciences and Engineering Research
Council of Canada for a research grant to support this work
and a fellowship to C. W. R., and the University of British
Columbia for a fellowship to C. W. R.
[Ru(bpy)2{Ph2P(o-OC6H4)-P,O}](PF6) 4. Prepared by
reacting [Ru(bpy)2(Me2CO)2](BF4)2 with 2 equivalents of POMe
in refluxing acetone, or by reacting [Ru(bpy)2(POMe-P,O)]-
(PF6)2 with one equivalent of POMe in refluxing acetone. Meta-
thesis to the PF6 salt followed by recrystallization from acetone/
ether or hot methanol provides the aryloxide complex as a
black powder in good yield. 31P{1H} NMR (81 MHz, 25 ЊC,
CD2Cl2): δ 54.0 (s, PPh2(o-OC6H4), Ϫ144 (septet, 1JPF = 711 Hz,
References
1 C. W. Rogers and M. O. Wolf, Chem. Commun., 1999, 2297.
2 A. Maercker, Angew. Chem., Int. Ed. Engl., 1987, 26, 972.
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J. Chem. Soc., Dalton Trans., 2001, 1278–1283
Rogers, Cerrie W.
