Formation of ruthenium(II)-bis(phosphine) monoxide complexes from the bis(phosphine) precursors: BINAP-monoxide (BINAPO) as a six-electron (P,O,η2-naphthyl) donor

Article abstract of DOI:10.1021/om0205344

Formation of ruthenium(II)-bis(phosphine) monoxide complexes from the bis(phosphine) precursors was discussed. BINAP-monoxide (BINAPO) as a six-electron donor was investigated. A novel coordination mode of BINAPO was identified by X-ray crystallography.

Full text of DOI:10.1021/om0205344

4672
Organometallics 2002, 21, 4672-4679
F or m a tion of Ru th en iu m (II)-Bis(p h osp h in e) Mon oxid e
Com p lexes fr om th e Bis(p h osp h in e) P r ecu r sor s:
BINAP -Mon oxid e (BINAP O) a s a Six-Electr on (P ,O,η2-
Na p h th yl) Don or
Paul W. Cyr, Steven J . Rettig,† Brian O. Patrick, and Brian R. J ames*
Department of Chemistry, University of British Columbia, 2036 Main Mall,
Vancouver, British Columbia, V6T 1Z1
Received J uly 8, 2002
Aerobic oxidation of one P atom in cis-RuCl2(P-P)(L2) complexes (P-P ) (R)-BINAP (2,2′-
bis(diphenylphosphino)-1,1′-binaphthyl) or dppb (1,4-bis(diphenylphosphino)butane), L2 )
bipy (2,2′-bipyridine) or phen (1,10-phenanthroline)) generates species such as [RuCl-
(BINAPO)(L2)]PF6 and cis-RuCl2(dppbO)(L2) containing the corresponding bis(phosphine)
monoxide ligands [BINAPO ) 2-(diphenylphosphinoyl)-2′-(diphenylphosphino)-1,1′-(binaph-
thyl), and dppbO ) 1-(diphenylphosphinoyl)-4-(diphenylphosphino)butane)]. A novel coor-
dination mode of BINAPO, involving the PIII atom, the O atom, and an η2-naphthyl interaction
proximate to the oxidized P atom, is identified by X-ray crystallography.
In tr od u ction
The use of Ru(II) systems with tetradentate “P2N2”
ligands for catalytic hydrogenation15 and epoxidation16
reactions has also been reported. Of particular note,
spectacular success has been achieved more generally
in the use of chiral Ru(II) complexes with phosphine
(either mono- or bidentate) and diamine (or amine-
amido) ligands in catalytic enantioselective hydrogena-
tion.17 Recently we have been exploring the chemistry
of a series of “Ru(P-P)(L2)” complexes where P-P )
dppb (1,4-bis(diphenylphosphino)butane) or (R)-BINAP,
The synthesis and chemistry of Ru(II) complexes
possessing a chelating, ditertiary phosphine ligand (P-
P) remains a topic of interest in our group, the main
impetus being the potential of such complexes as
hydrogenation catalysts.1-4 The use of chiral Ru(II)(P-
P) complexes for asymmetric catalysis has been tremen-
dously successful, especially in enantioselective hydro-
genation,5 and there has been much interest in the
chemistry of Ru(II) complexes bearing chiral diphos-
phine ligands such as BINAP4,6-9 and the related
BIPHEP10-12 ligands (Scheme 1). We have also studied
Ru(II) complexes containing both P- and N-donor ligand
sets, either with separate P- and N-donors13 or in which
the N-donor is incorporated into the phosphine ligand.14
(8) (a) MacFarlane, K. S.; Rettig, S. J .; Liu, Z.; J ames, B. R. J .
Organomet. Chem. 1998, 557, 213. (b) Geneˆt, J . P.; Mallart, S.; Pinel,
C.; J uge, S.; Laffitte, J . A. Tetrahedron: Asymmetry 1991, 2, 43. (c)
Geneˆt, J . P.; Pinel, C.; Ratovelomanana-Vidal, V.; Mallart, S.; Pfister,
X.; Can˜o de Andrade, M. C.; Laffitte, J . A. Tetrahedron: Asymmetry
1994, 5, 665.
(9) (a) Wiles, J . A.; Lee, C. E.; MacDonald, R.; Bergens, S. H.
Organometallics 1996, 15, 3782. (b) Wiles, J . A.; Bergens, S. H. J . Am.
Chem. Soc. 1997, 119, 2940. (c) Wiles, J . A.; Bergens, S. H. Organo-
metallics 1999, 18, 3709. (d) Wiles, J . A.; Bergens, S. H.; Young, V. G.
Can. J . Chem. 2001, 79, 1019.
† Deceased October 27, 1998.
* Corresponding author. E-mail: brj@chem.ubc.ca. Fax: (1)-(604)-
822 2847.
(1) J ames, B. R.; MacMillan, R. S.; Morris, R. H.; Wang, D. K. W.
Adv. Chem. Ser. 1978, 167, 122.
(2) J oshi, A. M.; Thorburn, I. S.; Rettig, S. J .; J ames, B. R. Inorg.
Chim. Acta 1992, 198-200, 283.
(10) (a) Mezzetti, A.; Tschumper, A.; Consiglio, G. J . Chem. Soc.,
Dalton Trans. 1995, 49. (b) Mezzetti, A.; Costella, L.; Del Zotto, A.;
Rigo, P.; Consiglio, G. Gazz. Chim. Ital. 1993, 123, 155.
(11) Currao, A.; Feiken, N.; Macchioni, A.; Nesper, R.; Pregosin, P.
S.; Trabesinger, G. Helv. Chim. Acta 1996, 79, 1587.
(12) (a) Feiken, N.; Pregosin, P. S.; Trabesinger, G.; Scalone, M.
Organometallics 1997, 16, 537. (b) Feiken, N.; Pregosin, P. S.; Trabe-
singer, G. Organometallics 1997, 16, 3735.
(13) (a) Batista, A. A.; Polato, E. A.; Queiroz, S. L.; Nascimento, O.
R.; J ames, B. R.; Rettig, S. J . Inorg. Chim. Acta 1995, 230, 111. (b)
Fogg, D. E.; Rettig, S. J .; J ames, B. R. Can. J . Chem. 1995, 73, 1084.
(c) Fogg, D. E.; Rettig, S. J .; J ames, B. R. Inorg. Chem. 1997, 36, 1961.
(14) (a) Hampton, C. R. S. M.; Butler, I. R.; Cullen, W. R.; J ames,
B. R.; Charland, J .-P.; Simpson, J . Inorg. Chem. 1992, 31, 5509. (b)
Mudalige, D. C.; Rettig, S. J .; J ames, B. R.; Cullen, W. R. J . Chem.
Soc., Chem. Commun. 1993, 830. (c) Schutte, R. P.; Rettig, S. J .; J oshi,
A. M.; J ames, B. R. Inorg. Chem. 1997, 36, 5809. (d) J ones, N. D.;
MacFarlane, K. S.; Smith, M. B.; Schutte, R. P.; Rettig, S. J ., J ames,
B. R. Inorg. Chem. 1999, 38, 3956.
(15) Gao, J .-X.; Ikariya, T.; Noyori, R. Organometallics 1996, 15,
1087.
(16) Stoop, R. M.; Bachmann, S.; Valentini, M.; Mezzetti, A. Orga-
nometallics 2000, 19, 4117.
(17) (a) Noyori, R.; Ohkuma, T. Angew. Chem., Int. Ed. 2001, 40,
40. (b) Abdur-Rashid, K.; Lough, A. J .; Morris, R. H. Organometallics
2001, 20, 1047. (c) Abdur-Rashid, K.; Faatz, M.; Lough, A. J .; Morris,
R. H. J . Am. Chem. Soc. 2001, 123, 7473.
(3) Fogg, D. E.; J ames, B. R.; Kilner, M. Inorg. Chem. 1994, 33, 85.
(4) MacFarlane, K. S.; Thorburn, I. S.; Cyr, P. W.; Chau, D. E. K.-
Y.; Rettig, S. J .; J ames, B. R. Inorg. Chim. Acta 1998, 270, 130.
(5) (a) Noyori, R. Asymmetric Catalysis in Organic Synthesis; J ohn
Wiley & Sons: New York, 1994. (b) Noyori, R. Acta Chem. Scand. 1996,
50, 380. (c) Geneˆt, J . P. In Reductions in Organic Synthesis: Recent
Advances and Practical Applications; Abdel-Magid, A. F., Ed.; ACS
Symposium Series 641; American Chemical Society: Washington, DC,
1996; p 31.
(6) For general reviews, see: (a) Noyori, R.; Takaya, H. Acc. Chem.
Res. 1990, 23, 345. (b) Kumobayashi, H. Recl. Trav. Chim. Pays-Bas
1996, 111, 201. (c) Noyori, R. Acta Chem. Scand. 1996, 50, 380.
(7) See for example: (a) Mashima, K.; Hino, T.; Takaya, H. J . Chem.
Soc., Dalton Trans. 1992, 2099. (b) Chan, A. S.; Laneman, S. A.; Day,
C. X. Inorg. Chim. Acta 1995, 228, 159. (c) Chen, C.-C.; Huang, T.-T.;
Lin., C.-W.; Cao, R.; Chan, A. S. C.; Wong, W. T. Inorg. Chim. Acta
1998, 270, 247. (d) Ohta, T.; Tonomura, Y.; Nozaki, K.; Takaya, H.
Organometallics 1996, 15, 1521. (e) Ashby, M. T.; Khan, M. A.;
Halpern, J . Organometallics 1991, 10, 2011. (f) Hoke, J . B.; Hollis, L.
S.; Stern, E. W. J . Organomet. Chem. 1993, 455, 193. (g) Doucet, H.;
Ohkuma, T.; Murata, K. Yokozawa, T.; Kozawa, M.; Katayama, E.;
England, A. F.; Ikariya, I.; Noyori, R. Angew. Chem., Int. Ed. 1998,
37, 1703.
10.1021/om0205344 CCC: $22.00 © 2002 American Chemical Society
Publication on Web 10/02/2002

Ru(II)-Bis(phosphine) Monoxide Complexes
Organometallics, Vol. 21, No. 22, 2002 4673
Sch em e 1
and L2 ) a chelating bis(N-donor) ligand.18,19 During
our studies on the solution chemistry of these RuCl2-
(P-P)(L2) complexes, we found that selective oxidation
of one P atom occurs, and complexes containing the
corresponding bis(phosphine) monoxide (BPMO) ligands
are produced (specifically dppbO and BINAPO in this
work).
benzylation of a diphosphine, followed by base hydroly-
sis of the recrystallized phosphonium salt,31 though this
route seems limited to diphosphines bearing just simple
alkyl (e.g., -(CH2)n-) bridges between phosphino groups.
Grushin has reported a Pd-catalyzed synthesis of BPMO
ligands from many commercially available diphosphines
(P-P), including BINAP.32 Other syntheses of BINAPO
have appeared;25b,26,27,33 however, with only one excep-
tion,26 these have been low yielding and generally pro-
ducing the monoxide as a byproduct. Gladiali et al.
synthesized BINAPO from 1,1′-binaphthyl-2,2′-diol in
a four-step procedure, followed by chiral resolution via
a Pd-C,N-cyclometalated complex.26 The coordination
chemistry of BINAPO is largely undeveloped, consider-
ing the vast literature on transition metal complexes
of BINAP and its derivatives.
In this paper, we report on the preparation of Ru(II)-
(dppbO) and Ru(II)(BINAPO) complexes directly from
Ru(II)(P-P) precursors. In addition, we report a novel
coordination mode of BINAPO in which the ligand acts
as a six-electron donor, involving the PIII and O atoms,
as well as an η2-naphthyl interaction of the binaphthyl
backbone with the Ru.
The coordination chemistry of BPMO ligands remains
of considerable interest, largely through studies to
improve transition-metal-catalyzed transformations.20
For example, a Rh/Ph2P(O)(CH2)2PPh2 catalyst system
allows for far less forcing conditions (80 °C and 50 psi)
compared to those typically employed (e.g., 200 °C and
500 psi) in the Monsanto acetic acid process using a
Rh-chloro(carbonyl) catalyst.21 Though BPMO ligands
have been known for some time,22 only more recently
have the catalytic properties of their complexes been
investigated. BPMO-based catalyst complexes have been
studied, for example, for hydroformylation,23-25a hy-
drosilylation,26 hydrovinylation,27 oligomerization, and
copolymerization.28 Faller et al. have reported exten-
sively on the chemistry of some arene complexes of Ru
and Os with BPMO ligands (especially chiral ones), as
well as their use as Lewis acid catalysts in Diels-Alder
reactions.29,30 Despite the interest, efficient general
syntheses of BPMOs have remained problematic. The
most general route involves a two-step process involving
Resu lts a n d Discu ssion
Recent work in this group has investigated the
solution chemistry of cis-RuCl2(P-P)(L2) complexes
(P-P ) dppb or (R)-BINAP, L2 ) bidentate N-donor)
and their potential in homogeneous catalytic hydroge-
nation of imines.18,19 Catalytic hydrogenations employ-
ing “Ru(II)(P-P)” complexes are often performed in
alcohol solvents, especially MeOH,3,5 and thus we
studied the nature of the species present in MeOH
solutions of cis-RuCl2(P-P)(L2). Conductivity studies
have shown that dissociation of one Cl- occurs, and
signals assignable to the cationic species are readily
detected by 31P{1H} NMR.18,19b However, such spectra
(18) Queiroz, S. L.; Batista, A. A.; Oliva, G.; Gambardella, M. T. P.;
Santos, R. H. A.; MacFarlane, K. S.; Rettig, S. J .; J ames, B. R. Inorg.
Chim. Acta 1998, 267, 209.
(19) (a) Cyr, P. W.; Patrick, B. O.; J ames, B. R. Chem. Commun.
2001, 1570. (b) Cyr, P. W. Ph.D. Dissertation, The University of British
Columbia, Vancouver, 2001.
(20) (a) Bader, A.; Lidner, E. Coord. Chem. Rev. 1991, 108, 27. (b)
Slone, C. S.; Weinberger, D. A.; Mirkin, C. A. Prog. Inorg. Chem. 1999,
48, 233.
(21) Wegman, R. W.; Abatjoglou, A. G.; Harrison, A. M. J . Chem.
Soc., Chem. Commun. 1987, 1891.
(22) Grim, S. O.; Satek, L. C.; Tolman, C. A.; J esson, J . P. Inorg.
Chem. 1975, 14, 656.
(23) (a) Abu-Gnim, C.; Amer, I. J . Chem. Soc., Chem. Commun.
1994, 115. (b) Abu-Gnim, C.; Amer, I. J . Organomet. Chem. 1996, 516,
235.
(24) Gladiali, S.; Alberico, E.; Pulacchinni, S.; Kolla`r, L. J . Mol.
Catal. A: Chem. 1999, 143, 155.
(25) (a) Gladiali, S.; Medici, S.; Ke´gl, T.; Kolla`r, L. Monatsh. Chem.
2000, 131, 1351. (b) Bunten, K. A.; Farrar, D. H.; Poe¨, A. J .; Lough, A.
Organometallics 2002, 21, 3344. This paper, on the oxidation of RhCl-
(CO)(BINAP) to give RhCl(CO)(BINAPO), appeared after the submis-
sion of our paper.
(29) (a) Faller, J . W.; Patel, B. P.; Albrizzio, M. A.; Curtis, M.
Organometallics 1999, 18, 3096. (b) Faller, J . W.; Liu, X.; Parr, J .
Chirality 2000, 12, 325. (c) Faller, J . W.; Parr, J . Organometallics 2000,
19, 3556. (d) Faller, J . W.; Grimmond, B. J .; D’Alliessi, D. G. J . Am.
Chem. Soc. 2001, 123, 2525.
(30) (a) Faller, J . W.; Parr, J . Organometallics 2000, 19, 1829. (b)
Faller, J . W.; Parr, J . Organometallics 2001, 20, 697. (c) Faller, J . W.;
Lavoie, A. R.; Grimmond, B. J . Organometallics 2002, 21, 1662.
(31) Abatjotglou, A. G.; Kapicak. L. A. US Patent 4 429 161, 1984.
(32) (a) Grushin, V. V. J . Am. Chem. Soc. 1999, 121, 5831. (b)
Grushin, V. V. Organometallics 2001, 20, 3950.
(26) Gladiali, S.; Pulacchini, S.; Fabbri, D.; Manassero, M.; Sansoni,
M. Tetrahedron: Asymmetry 1998, 9, 391.
(27) Nandi, M.; J in, J .; RajanBabu, T. V. J . Am. Chem. Soc. 1999,
121, 9899.
(28) Brassat, I.; Keim, W.; Killat, S.; Mo¨thrath, M.; Mastrorilli, P.;
Nobile, C. F.; Suranna, G. P. J . Mol. Catal. A: Chem. 2000, 157, 41.
(33) (a) Ozawa, F.; Kubo, A.; Hayashi, T. Chem. Lett. 1992, 2177.
(b) Cai, D.; Payackl, J . F.; Bender, D. R.; Hughes, D. L.; Verhoeven, T.
R.; Reider, P. J . J . Org. Chem. 1994, 59, 7180.

4674 Organometallics, Vol. 21, No. 22, 2002
Cyr et al.
F igu r e 2. ORTEP representation of [RuCl(BINAPO)-
(bipy)]PF6 (3a ‚PF6). Thermal ellipsoids are drawn at 50%
-
probability. The phenyl C atoms and the PF6 anion are
omitted for clarity.
F igu r e 1. 31P{1H} NMR spectra of cis-RuCl2((R)-BINAP)-
(phen) (2) in CD3OD exposed to air at rt over (a) 2 h, (b) 5
days, (c) 14 days.
of CD3OD solutions of cis-RuCl2((R)-BINAP)(L2) (L2 )
bipy (1), phen (2)) in air at room temperature (rt) change
over time, as exemplified for 2 in Figure 1. Initially, the
neutral species 2 and a monocationic complex thought
to be19b [RuCl((R)-BINAP)(phen)(MeOH)]Cl are present
(Figure 1a), but over days signals of these species
disappear and four new singlets appear (Figure 1b,c)
that result from BINAPO complexes. After ∼14 days,
no further changes occur in the spectra and the
product ratios remain constant. The products are iso-
lated as [RuCl(BINAPO)(L2)]PF6 (L2 ) bipy (3‚PF6),
phen (4‚PF6)), after the addition of NH4PF6. The spec-
troscopic and analytical data are consistent with isomers
(denoted a and b) of each of these formulations (see
Experimental Section). Thus, aerobic oxidation of one
of the P atoms has taken place. The two 31P{1H} NMR
singlets for 3 and 4 are consistent with a relatively small
F igu r e 3. ORTEP representation of [RuCl(BINAPO)-
(phen)]PF6 (4a ‚PF6). Thermal ellipsoids are drawn at 50%
-
probability. The PF6 anion is omitted for clarity.
3
or zero J PP value, as observed for Pd, Pt, and Rh
Ta ble 1. Selected Bon d Dista n ces (Å) a n d An gles
complexes of BINAPO;24-26 the assignments of the
singlets (to PIII and PV) are not obvious in view of the
novel type of P,O,η2-naphthyl bonding of the BINAPO
discovered in the X-ray structures (see below). The
complex [(p-cymene)RuCl(P,O-BINAPO)]SbPF6 was orig-
inally reported to give rise to two 31P{1H} doublets,30a
(d eg) for [Ru Cl(BINAP O)(bip y)]P F 6 (3a ‚P F 6)
Ru(1)-Cl(1)
Ru(1)-O(1)
Ru(1)-N(2)
Ru(1)-C(32)
C(23)-C(32)
2.384(1)
2.212(3)
2.113(4)
2.255(4)
1.444(6)
Ru(1)-P(1)
Ru(1)-N(1)
Ru(1)-C(23)
P(1)-O(1)
2.320(1)
2.057(3)
2.346(4)
1.518(3)
3
although a later publication reports no J PP values for
P(1)-Ru(1)-O(1)
86.79(8) Ru(1)-O(1)-P(2)
97.2(1)
Cl(1)-Ru(1)-C(32) 161.1(1)
96.6
this complex, the discrepancy being unmentioned.29d
Cl(1)-Ru(1)-C(23) 161.4(1)
dihedral of naphthyl planes
Str u ctu r es of 3a a n d 4a . The structures of 3a ‚PF6
and 4a ‚PF6 were determined by X-ray crystallography
(Figures 2 and 3, respectively). The coordination envi-
ronments of 3a and 4a are the same, including the
stereochemistry, and the corresponding Ru-N, Ru-P,
and Ru-Cl bond lengths are essentially identical (see
Tables 1 and 2). The PdO bond distances are the same
within error (av 1.516 Å) and are in the range typical
for coordinated R3PdO (1.49-1.52 Å).34 Uncoordinated
BINAPO has not been crystallographically character-
ized, although three reports of the structure of BINAP-
(O)2 have appeared.8a,35,36 The one by Bunten et al.,36
unlike the earlier ones,8a,35 characterized BINAP(O)2 in
the absence of cocrystallized materials, and thus for
structural comparison their data will be used. In the
reported structures25b,26,30a,b and those here of coordi-
nated BINAPO, the PdO bond length is greater than
that in BINAP(O)2 (av 1.4827 Å).36
In 3a and 4a , the two C atoms of the naphthyl ring
proximate to the PdO group are η2-coordinated to
the Ru, and this leads to a substantial decrease in the
(35) Takaya, H.; Mashima, K.; Koyano, K.; Yagi, M.; Kumobayashi,
H.; Taketomi, T.; Akutagawa, S. J . Org. Chem. 1986, 51, 629.
(36) Bunten, K. A.; Farrar, D. H.; Lough, A. J . Acta Crystallogr. Sect.
C: Cryst. Struct. Commun. 2000, C56, e267.
(34) Orpen, G. A.; Brammer, L.; Allen, F. H.; Kennard, O.; Watson,
D. G.; Taylor, R. J . Chem. Soc., Dalton Trans. 1989, S1.

Ru(II)-Bis(phosphine) Monoxide Complexes
Organometallics, Vol. 21, No. 22, 2002 4675
Ta ble 2. Selected Bon d Dista n ces (Å) a n d An gles
occupy more pseudoequatorial positions. A similar ar-
rangement of the Ph rings has also been observed in
Ru(II) complexes of related diphosphine ligands that
coordinate via the two P atoms and two C atoms of a
biaryl group.38 The dihedral angles between the planes
of the naphthyl rings of the binaphthyl backbone of
BINAPO in 3a and 4a are 96.6° and 81.6°, respectively.
The value of this angle for 4a is similar to that in
BINAPO complexes of Pd (82.1(1)°),26 Ru (83.6°),30a and
Os (81(1)°),30b in which only P,O-coordination occurs,
and is also similar to that for P,P′,η2-coordinated BINAP
bound to Ru (80°).37 However, the dihedral angle in 3a
is larger than that typically observed in BINAP7a,e,f and
BINAPO26,30a,b systems and is even greater than that
in BINAP(O)2 (94.17°).36 Upon changing from P,P′- to
P,P′,η2-naphthyl coordination, the dihedral angle of
BINAP increases from 66° to 80° ((Cp)RuI(BINAP) vs
[(Cp)Ru(BINAP)]+).37 Similarly, this dihedral angle in
4a (81.6°) is greater than that in cis-RuCl2((R)-BINAP)-
(phen), 2 (77.37°),19 although the oxidation of the
phosphine may also be a factor; the dihedral angle of
the binaphthyl rings in uncoordinated BINAP (88.3°)39
is substantially less than that in BINAP(O)2 (94.17°).36
The reason for the large difference of this angle in 3a
and 4a is not obvious and may be a result of crystal-
packing effects.
To summarize then the structural findings, 3a and
4a represent the first characterized P,O,η2-naphthyl
coordination mode of the new class of biaryl-bridged bis-
(phosphine) monoxide ligands. P,P′,η2-naphthyl coordi-
nation of BINAP is known,37,38 and similar bonding in
some Ru(MeO-BIPHEP) complexes has been re-
ported.12a,38 A related novel coordination mode of PPh3,
via the P atom and an η2-phenyl interaction, has also
been reported.40 Worth noting is that Faller et al. have
prepared [(p-cymene)M(BINAPO) ]2+ in situ (M ) Ru,
Os), which they formulate as solvated species;30 it is not
impossible that the corresponding isolated complexes
might exhibit the P,O,η2- coordination mode of BINAPO
found in 3a ‚PF6 and 4a ‚PF6 in order to compensate for
coordinative unsaturation.
(d eg) for [Ru Cl(BINAP O)(p h en )]P F 6 (4a ‚P F 6)
Ru(1)-Cl(1)
Ru(1)-O(1)
Ru(1)-N(2)
Ru(1)-C(34)
C(25)-C(34)
2.377(2)
2.196(4)
2.137(6)
2.356(7)
1.463(9)
Ru(1)-P(2)
Ru(1)-N(1)
Ru(1)-C(25)
P(1)-O(1)
2.311(2)
2.051(5)
2.281(7)
1.515(4)
P(2)-Ru(1)-O(1)
87.71(12) Ru(1)-O(1)-P(1)
98.6(2)
Cl(1)-Ru(1)-C(25) 161.5(2)
Cl(1)-Ru(1)-C(34) 160.6(2)
dihedral of naphthyl planes
81.6
PdO-Ru angle in 3a and 4a (97.2(1)° and 98.6(2)°,
respectively) relative to the heterobidentate P,O-chelat-
ing mode of BINAPO, where the PdO-M angles are
125.1(2)° (M ) Pd),26 165.9(3)° (M ) Ru),30a and 161.5-
(5)° (M ) Os).30b Also, the P-Ru-O bite angle of
BINAPO in 3a and 4a (av 87.2°) is greater than that in
[(p-cymene)RuCl(P,O-BINAPO)]+ (81.5(1)°).30a
Coordination of the naphthyl group in 3a and 4a leads
to an elongation of the Ru-bonded C-C bond, 1.444(6)
and 1.463(9) Å, respectively, relative to the correspond-
ing uncoordinated C-C bond in [(p-cymene)RuCl(P,O-
BINAPO)]+ of 1.39(1) Å,30a which is identical to that in
BINAP(O)2.36 These C-C bond distances in 3a and 4a
are close to those in [(Cp)Ru(BINAP)]+ (1.464(14) Å),
which possesses BINAP coordinated in a related P,P′,η2-
mode.37 Coordination of the naphthyl ring in 3a and 4a
causes significant disruption of the aromaticity of the
naphthyl moiety, and inspection of the C-C bond
lengths in the separate naphthyl groups suggests lo-
calization of double bonds in the coordinated rings
(Supporting Information). Such disruption of the aro-
maticity of the η2-coordinated aromatic rings of BINAP37
and MeO-BIPHEP12a ligands in related coordination
modes has been noted. The average Ru-C bond lengths
in 3a (2.300 Å) and 4a (2.318 Å) are relatively long
compared to the analogous Ru-C(naphthyl) bonds in
[(Cp)Ru(BINAP)]+ (av 2.270 Å)37 and to conventional
Ru-C bonds in Ru(arene) and Ru(olefin) complexes
(2.10-2.30 Å).34 The Ru-C bond distances within both
3a and 4a are unequal. In 3a , the Ru-C(23) bond
length is longer than the Ru-C(32) length (2.346(4) vs
2.255(4) Å, respectively), and in 4a the Ru-C(34) bond
distance is greater than that of Ru-C(25) (2.356(7) vs
2.281(7) Å, respectively). In contrast, the Ru-C bond
lengths in [(Cp)Ru(BINAP)]+ are very similar to each
other (within twice their esd’s) at 2.258(7) and 2.281(9)
Å,37 as are those of the related complex [Ru(η6-in-
dole)(MeO-BIPHEP-Bu)]2+ (2.34(3) and 2.31(3) Å).38
However, noticeably different Ru-C bond lengths are
present in the related [(η5-C8H11)Ru(MeO-BIPHEP-Pr)]-
CF3CO2 (2.299(5) and 2.366(5) Å).12a While the two
Ru-C bond distances within each of 3a and 4a are
different, the nearly identical Cl-Ru-C angles (av 161°)
suggest a symmetric displacement of the bound “ole-
finic” moiety.
Syn th esis of 3 a n d 4. The ratio of the isomers of 3
and 4 formed (a :b, cf. Figure 1) varied depending on
reaction conditions. Thus, refluxing a MeOH solution
of cis-RuCl2((R)-BINAP)(bipy), 1, in air for 48 h, followed
by addition of NH4PF6, yielded 3a ‚PF6 and 3b‚PF6 in a
1:9 ratio, compared to a 3:2 ratio obtained after 14 days
for the rt reaction. Complexes 3‚PF6 and 4‚PF6 may
also be prepared by aerobic oxidation of the correspond-
ing [RuCl((R)-BINAP)(L2)]PF6 species which are pro-
duced in situ by reaction of cis-RuCl2((R)-BINAP)(L2)
with AgPF6 in CH2Cl2.19b These cationic complexes
presumably possess BINAP bound in a P,P′,η2-naph-
thyl mode, as evidenced from the 31P NMR data, which
show one signal shifted well upfield, this being a
recognized characteristic of “tridentate” BINAP.37,38 For
example, a CD2Cl2 solution of 1 plus 1.2 equiv of
AgPF6 gives an AX pattern in the 31P{1H} spectrum (δA
Another consequence of the naphthyl coordination of
BINAPO in 3a and 4a is a change in the orientation of
the Ph rings, from the usual axial/equatorial alter-
nating arrangement as seen in [(p-cymene)RuCl(P,O-
BINAPO)]+,30a to one in which three of the Ph rings
2
) 68.0, δX ) 10.6, J AX ) 30.6 Hz), very different
from the 31P{1H} data for
1
(δ 47.2 (s)).19 The
η2-naphthyl binding in [RuCl(BINAP)(L2)]+ is only
(37) Pathak, D. D.; Adams, H.; Bailey, N. A.; King, P. J .; White, C.
J . Organomet. Chem. 1994, 479, 237.
(38) Feiken, N.; Pregosin, P. S.; Trabesinger, G.; Albinati, A.; Evoli,
G. L. Organometallics 1997, 16, 5756.
(39) Deeming, A. J .; Speel, D. M. Stchedroff, M. Organometallics
1997, 16, 6004.
(40) Cheng, T.-Y.; Szalda, D. J .; Bullock, R. M. Chem. Commun.
1999, 1629.

4676 Organometallics, Vol. 21, No. 22, 2002
Cyr et al.
Sch em e 2a
a
In c, P-PO ) BINAPO.
present in noncoordinating or weakly coordinating
solvents, as the solvento complexes [RuCl(BINAP)(L2)-
(solvent)]+ exist in solvents such as MeOH or MeCN (cf.
Figure 1).19b
compared to that of the PV atom, has been demonstrated
from ligand substitution reactions of Pt(II)-BINAPO
systems.24
The 31P{1H} NMR data suggest that the products of
reaction of 3b/4b with simple donor ligands have
structure c (L ) MeCN or CO) as shown in Scheme 2.
The stability of 3a /4a shows that the facial P,O,η2-
coordination of BINAPO is kinetically stable (struc-
ture a , Scheme 2), in contrast to the ready displace-
ment of the η2-naphthyl moiety observed for complexes
with P,P′,η2-bonding modes of BINAP and MeO-
BIPHEP.12a,37,38 Two structures for 3b/4b seem plau-
sible: b in Scheme 2, in which the η2-naphthyl moiety
is coordinated trans to a N atom, or c, in which L is a
vacant site trans to the coordinated P atom. In solution,
a weakly coordinated solvent molecule may occupy this
vacant site. The instability of 3b/4b in noncoordinating
or weakly coordinating solvents and the 31P{1H} evi-
dence that reaction with MeCN or CO gives products
with the incoming ligand trans to the P atom favor
structure c.
The addition of base (e.g., NEt3, aqueous NaOH, or
KOtBu) markedly accelerates the formation of the
BINAPO species from cis-RuCl2(BINAP)(L2) and gives
a single product isomer. For example, the 31P{1H} NMR
spectrum of a CD3OD solution of 1, 2 h after addition
of ∼10 equiv of NaOH, consists solely of two singlets (δ
70.9 and 58.9), which are assigned to 3a ‚Cl; for the
isolated 3a ‚PF6 in CD2Cl2 the singlets are seen at δ 69.8
and 56.6 (see Experimental Section). Similar results
were also obtained with the other bases; however,
isolation of clean products from these reactions was
difficult.
R ea ct ivit y of 3 a n d 4. Methanolic solutions of 3‚
PF6 and 4‚PF6 are air-stable for weeks. However, in
CD2Cl2 or CDCl3 solution, exposure to air causes a color
change from yellow to green within 48 h. 31P{1H} NMR
analysis of the resulting solutions indicates that 3a ‚PF6
and 4a ‚PF6 do not decompose, but 3b‚PF6 and 4b‚PF6
do. Thus, the nonstructurally characterized b isomers
are more reactive than the a isomers. While 3‚PF6 and
4‚PF6 do not react with H2, reactivity with CO or MeCN
occurs, but only with the b isomers. For example,
reaction of 3‚PF6 with 10 equiv of MeCN in CD2Cl2
results in the disappearance of the signals due to 3b‚
PF6 and generation of a new set of signals (δ 54.5 s,
50.7 s) proposed to be due to [RuCl(P,O-BINAPO)(bipy)-
(MeCN)]PF6. The ratio of this new nitrile species to 3a ‚
PF6 is the same as the 3b:3a ratio prior to MeCN
addition. These ratios remain unchanged for 7 days,
showing that any possible equilibrium between 3a ‚PF6
and 3b‚PF6 is exceedingly slow to establish. Similarly,
a solution of 4‚PF6 under 1 atm of CO shows signals
due to 4a ‚PF6 and [RuCl(P,O-BINAPO)(phen)(CO)]PF6
(δ 54.2 s, 13.3 s).19b The upfield signal, relative to those
of 4b‚PF6 (δ 64.9 s, 59.9 s), is indicative of a P atom
trans to CO,41 and the magnitude of the shift suggests
that CO is trans to the PIII atom, as greater sensitivity
of the 31P chemical shift of the unoxidized P atom,
Syn th esis a n d Rea ctivity of d p p bO Com p lexes.
Aerobic oxidation of phosphine in cis-RuCl2(dppb)(L2)
(L2 ) bipy (5), phen (6)) to give complexes containing
dppbO also occurs, although this reaction is much
slower relative to those with the analogous BINAP
complexes. Again, addition of base markedly increases
the rate of formation of the BPMO species. Thus, while
formation of cis-RuCl2(dppbO)(bipy) (7) is incomplete
after 30 days at rt in MeOH, the reaction is quantitative
in <1 h in the presence of ∼10 equiv of base, as judged
by 31P{1H} NMR. As for 3‚PF6 and 4‚PF6, the 31P{1H}
NMR spectra of 7 and 8 consist of a singlet for each P
atom (7: δ 53.4, 32.2; 8: δ 53.7, 32.0), and only one
product is observed for the dppbO species (i.e., only one
geometric isomer is formed). As 5 and 6 are formed as
a racemic mixture,18 it is assumed that 7 and 8 are also
prepared as racemates. On the basis of the NMR and
IR spectroscopic data, 7 and 8 are proposed to be
neutral, six-coordinate, cis-dichloro complexes in which
dppbO is P,O-coordinated. Within cis-dichloro species,
the PV atom can be trans to N or Cl, while the PIII atom
will be correspondingly trans to Cl or N. Though the
dppbO ligand in these complexes might be expected to
be hemilabile,20,29 displacement of the coordinated phos-
phine oxide “arm” to give η1-dppbO is not facile. For
(41) (a) Wilkes, L. M.; Nelson, J . H.; Mitchener, J . P.; Babich, M.
W.; Riley, W. C.; Helland, B. J .; J ocobson, R. A.; Cheng, M. Y.; Seff,
K.; McCusker, L. B. Inorg. Chem. 1982, 21, 1376. (b) Krassowski, D.
W.; Nelson, J . H.; Brower, K. R.; Hauenstein, D.; J acobson, R. A. Inorg.
Chem. 1988, 27, 4294.

Ru(II)-Bis(phosphine) Monoxide Complexes
Organometallics, Vol. 21, No. 22, 2002 4677
example, the 31P{1H} NMR spectrum of 7 remains
unchanged after the addition of 100 equiv of MeCN or
1 atm of CO to a CDCl3 solution of the complex.
Mech a n ism of Oxid a tion . While oxidation of a
coordinated phosphine to phosphine oxide is well-
known, and indeed catalytic systems employing transi-
tion metal complexes have been developed for such
oxidations,32,42-44 examples of aerobic oxidation of a
coordinated chelating diphosphine to give a coordinated
phosphine oxide group are relatively rare.25b,45 There
are examples of reaction of coordinated BINAP in
Ru(II) systems to give complexes in which P-O bonds
have formed; however, these also involve cleavage of a
P-C(naphthyl) bond and, for example, subsequent
hydrolysis to give the 2-diphenylphosphino-1,1′-binaph-
thyl ligand, either coordinated in a P,η4-naphthyl (with
Ph2PdO co-ligand)46 or a P,η6-naphthyl (with Ph2P(OH)
co-ligand)47 fashion. Similar reactivity also occurs with
related MeO-BIPHEP complexes.47,48 Subsequent oxi-
dation of the coordinated P atom in the Ph2P(OH)
fragment, which was cleaved from the original BINAP
or MeO-BIPHEP ligands, in the presence of H2O has
also been reported.49
signal remains unchanged. The broadening likely re-
sults from coordinative competition of H2O and MeOH,
and similar broadening due to such solvent exchange
has been observed in the 31P{1H} NMR spectra of Ru-
(II),51 as well as Rh(I) and Ir(I) complexes.52 At -60 °C,
the solution spectrum consists of signals due to 1, [RuCl-
((R)-BINAP)(bipy)(CD3OD)]+, and an AX pattern that
we assign to [RuCl((R)-BINAP)(bipy)(H2O)]+ (δA ) 58.5,
2
δX ) 49.8, J AX ) 37.8 Hz). The oxidation of the
phosphine occurs slower in the presence of the added
H2O, being only ∼75% complete after 14 days at rt,
compared to 100% completion in the absence of added
H2O. Also, under an Ar atmosphere, low conversion of
1 to 3 occurs in a MeOH solution with >50 equiv of H2O
added, even in the presence of added base: after 1 h,
<10% conversion to 3 is observed, and the same reaction
in air gives 100% conversion after this time. Of note, a
solution of 2 in CD3OD under 1 atm of O2 showed no
conversion to the BINAPO species 4 after 1 week,
relative to ∼70% conversion obtained when the reaction
is performed in air (cf. Figure 1). The available data
implicate the necessity of both O2 and H2O for the
formation of the BPMO complexes. No reduced coprod-
uct has been identified (cf. eq 1), although the high
yields of the isolated complexes indicate that sacrificial
reduction of Ru does not occur; reduction of O2 with
involvement of peroxide (or superoxide) is plausible (see
below). Labeling experiments using H218O were incon-
clusive in IR studies because of a preponderance of
bands present in the ν(PdO) region for 3 and 4, while
mass spectrometry data showed no detectable incorpo-
ration of 18O into these complexes.
Our preliminary investigations on the mechanism of
formation of the BPMO complexes from the cis-RuCl2-
(P-P)(L2) species have not been conclusive. The en-
hancement of reaction rate by base could indicate the
involvement of OH-, as in the well-established chem-
istry shown in eq 1.42,50 To investigate the source of the
PIII + OH- f PVdO + H+ + 2e
(1)
The direct use of peroxides as oxidant was also
examined. Addition of ∼5 equiv of H2O2 (30% aqueous)
to a CD3OD solution of 1 caused immediate efferves-
cence, and the 31P{1H} spectrum of this solution ob-
tained within 5 min shows the presence of a Ru-
(BINAPO) species (δ 74.3 s, δ 59.9 s), probably 3a ‚Cl
and free BINAP(O)2 (δ 36.1 s) in a 1:3 ratio. Complete
oxidation to BINAP(O)2 occurred within 15 min. The
31P{1H} spectrum of a CD3OD solution of 1 with 1 equiv
of cumene hydroperoxide after 15 min shows the pres-
ence of 1, [RuCl((R)-BINAP)(bipy)(CD3OD)]+, and an-
O atom in the BPMO products, the effects of H2O and
O2 on the reaction were examined. A CD3OD solution
of 1 and ∼250 equiv of H2O exposed to air was
monitored by 31P{1H} NMR. The initial spectrum was
notably different from that obtained without the added
water, which is similar to that shown in Figure 1. In
the presence of excess water, signals due to 1 were
absent, and the more upfield signal of the cationic
species is substantially broadened while the downfield
(42) Sima´nadi, L. I. Catalytic Activation of Dioxygen by Metal
Complexes; Kluwer Academic Publishers: Dordrecht, 1992; Chapter
11.
2
other species (δA ) 50.7, δX ) 42.5, J AX ) 35.1 Hz),
possibly an alkylperoxide-containing complex, in a 1:2:4
ratio, respectively. Within 3 h, the formation of 3 is
detected, and within 5 days there is complete conversion
to 3a and 3b in the same 3:2 ratio produced in the
absence of added peroxide. Oxidation of coordinated
PPh3 via platinum metal-OOH species (including those
of Ru) has also been documented.45d,53
The oxidation of the diphosphine ligand in some
Ru(II)(P-P) systems under catalytic epoxidation condi-
tions using PhIO has been noted.54,55 Related to the cis-
RuCl2(P-P)(L2) complexes discussed here are the [RuCl-
(P2N2)]+ complexes, where P2N2 ) a chiral tetradentate
(43) Sen, A.; Halpern, J . J . Am. Chem. Soc. 1977, 99, 8337.
(44) For examples involving Ru, see: (a) Graham, B. W.; Laing, K.
R.; O’Connor, C. J .; Roper, W. R. J . Chem. Soc., Dalton Trans. 1972,
1237. (b) Taqui Khan, M. M.; Siddiqui, M. R. H.; Hussain, A.; Moiz,
M. A. Inorg. Chem. 1986, 25, 2765. (c) Cheng, S. Y. S.; J ames, B. R. J .
Mol. Catal. A: Chem. 1997, 117, 91, and references therein.
(45) See, for example: (a) Anderson, W. A.; Carty, A. J .; Palenik,
G. J .; Schreiber, G. Can. J . Chem. 1971, 49, 761. (b) Balch, A. L.; Noll,
B. C.; Olmstead, M. M.; Toronto, D. V. Inorg. Chem. 1992, 31, 5226.
(c) Heinze, K.; Huttner, G.; Zsolnai, L. Chem. Ber. 1997, 130, 1393.
(d) J ia, G.; Ng, W. S.; Chu, H. S.; Wong, W.-T.; Yu, N. T.; Williams, I.
D. Organometallics 1999, 18, 3597.
(46) (a) Chan, A. S. C.; Laneman, S. A.; Miller, R. E. In Selectivity
in Catalysis; Davis, M. E., Suib, S. L., Eds.; ACS Symposium Series
517; American Chemical Society: Washington, DC, 1993; p 27. (b) Chan,
A. S. C.; Laneman, S. Inorg. Chim. Acta 1994, 223, 165.
(47) (a) den Reijer, C. J .; Wo¨rle, M.; Pregosin, P. S. Organometallics
2000, 19, 309. (b) den Reijer, C. J .; Dotta, P.; Pregosin, P. S.; Albiniti.
Can. J . Chem. 2001, 79, 693. (c) Geldbach, T. J .; Pregosin, P. S.;
Bassetti, M. Organometallics 2001, 20, 2990. (d) Geldbach, T. J .; den
Reijer, Wo¨rle, M.; C. J .; Pregosin, P. S. Inorg. Chim. Acta 2002, 330,
155.
(51) Ma, E. F. S. Ph.D. Thesis, University of British Columbia,
Vancouver, 1999.
(52) (a) Deeming, A. J .; Proud, G. P. Inorg. Chim Acta 1985, 100,
223. (b) Deeming, A. J .; Proud, G. P.; Dawes, H. M.; Hursthouse, M.
B. J . Chem. Soc., Dalton Trans. 1986, 2545.
(48) (a) den Reijer, C. J .; Ru¨egger, H.; Pregosin, P. S. Organome-
tallics 1999, 17, 5213. (b) Geldbach, T. J .; Drago, D.; Pregosin, P. S.
Chem. Commun. 2000, 1629.
(49) Geldbach, T. J .; Pregosin, P. S.; Albinati, A.; Rominger, F.
Organometallics 2001, 20, 1932.
(53) (a) J ames, B. R. Adv. Chem. Ser. 1980, 191, 253. (b) Suzuki,
H,; Matsuura, S.; Moro-Oka, Y.; Ikawa, T. J . Organomet. Chem. 1985,
286, 247.
(54) Bressan, M.; Morvillo, A. Inorg. Chem. 1989, 28, 950.
(55) Stoop, R. M.; Bauer, C.; Setz, P.; Wo¨rle, M.; Wong, T. Y. H.;
Mezzetti, A. Organometallics 1999, 18, 5691.
(50) Grushin, V. V.; Alper, H. Organometallics 1993, 12, 1890.

4678 Organometallics, Vol. 21, No. 22, 2002
Cyr et al.
Ta ble 3. Cr ysta llogr a p h ic Da ta for
[Ru Cl(BINAP O)(bip y)]P F 6 (3a ‚P F 6) a n d
[Ru Cl(BINAP O)(p h en )]P F 6 (4a ‚P F 6)
diphosphine-diimine or -diamine ligand; these catalyze
asymmetric epoxidation of olefins with H2O2, and phos-
phine oxide-containing species are considered to be
formed by reaction of the [RuCl(P2N2)]+ complexes with
H2O2.16
3a ‚PF6‚2CHCl3
4a ‚PF6‚CH3OH
chemical
formula
fw
space group
Z
C
56H42N2Cl7F6OP3Ru
C57H44N2ClF6O2P3Ru
1315.11
P212121 (No. 19)
4
1132.37
P43212 (No. 96)
8
Con clu sion s
The aerobic oxidation of one P atom of the bis-
(phosphine) ligand in cis-RuCl2(P-P)(L2) complexes
(L2 ) bipy or phen) generates products containing
the corresponding bis(phosphine) monoxide ligands (P-
PdO), and complexes of the type [RuCl(BINAPO)(L2)]-
PF6 and RuCl2(dppbO)(L2) have been synthesized. A
novel P,O,η2-coordination mode of BINAPO involving
the unoxidized P atom, the O atom, and an η2-naphthyl
interaction has been established.
a, Å
b, Å
13.2409(3)
20.0499(5)
20.387(1)
5412.2(3)
1.614
11.8013(3)
11.8013(3)
71.073(2)
9898.3(4)
1.520
c, Å
V, Å3
D
calcd, g cm-3
µ, cm-1
λ, Å
7.88
5.37
0.71069
-100
0.077, 0.111
0.71073
-100
0.1103; 0.1242
T, °C
R; Rw (on F2,
all data)a
a
2
R ) ∑||Fo| - |Fc||/∑|Fo|; Rw ) [∑[w(Fo - Fc2)2/∑[w(Fo2)2]]1/2
.
Exp er im en ta l Section
P r ep a r a t ion of [R u Cl(BINAP O)(p h en )]P F 6 (4‚P F 6).
Compound 4‚PF6 was prepared in a manner analogous to that
used for 3‚PF6. Thus, after a MeOH solution of cis-RuCl2((R)-
BINAP)(phen) (2) (33 mg, 0.034 mmol) was stirred in air for
17 days at rt, NH4PF6 (58 mg, 0.36 mmol) was added and the
resulting mixture stirred for 1.5 h. After workup, the yellow
product was isolated and dried in vacuo. Yield (as a mixture
of PF6 salts of isomers 4a and 4b): 32 mg (88%). Anal. Calcd
for C56H40N2ClF6OP3Ru: C, 61.13; H, 3.66; N, 2.55. Found: C,
61.10; H, 3.74; N, 2.69. 31P{1H} NMR (CD2Cl2): for 4a , δ 69.5
Gen er a l P r oced u r es. Unless stated otherwise, manipula-
tions were carried out under Ar using standard Schlenk
techniques. Reagent grade solvents (Fisher Scientific) were
distilled from Na (Et2O, hexanes), CaH2 (CH2Cl2), or Mg/I2
(MeOH) under N2. Deuterated solvents (CDCl3, CD2Cl2,
CD3OD) were obtained from Cambridge Isotope Laboratories
and dried if necessary over activated molecular sieves
(Fisher: type 4 Å), deoxygenated, and stored under Ar. Other
reagents were used as supplied by commercial vendors.
Ruthenium was obtained as RuCl3‚3H2O on loan from J ohnson
Matthey Ltd. or Colonial Metals Inc., and (R)-BINAP was a
gift from Dr. S. King (formerly of Merck). The RuCl2(P-P)-
(L2) complexes 1, 2, 5, and 6 were prepared by our reported
methods.18,19 Solution NMR spectra were recorded on a Varian
1
s, 57.3 s, and for 4b, δ 64.9 s, 59.9 s; -144.0 m J PF ) 710. H
NMR (CD2Cl2): δ 4.20-10.50 (br m, BINAPO and phen
protons). IR (KBr, cm-1): ν(PO) 1126 (w, 4a ) and 1159 (w, 4b),
ν(PF) 841. UV-vis (CH2Cl2): 416 [5,700]. LRMS [+LSIMS]:
955 (M+), 919 (M+ - Cl), 739 (M+ - Cl - phen). Slow
evaporation in air of the MeOH solution containing 2 and
excess NH4PF6 gave orange crystals of 4a ‚PF6 suitable for
X-ray analysis.
1
XL300 FT-NMR spectrometer (299.94 MHz for H, 121.42 MHz
for 31P), using residual solvent proton (1H) or external P(OMe)3
(31P: δ 141.0 vs external 85% aqueous H3PO4) as reference.
All J values are given in Hz. 31P chemical shifts are reported
with respect to 85% aqueous H3PO4, downfield shifts being
taken as positive. UV-vis spectra were recorded on a Hewlett-
Packard diode array spectrophotometer and are given as λ
(nm) [ꢀ (M-1 cm-1)], sh ) shoulder. IR spectra were recorded
on KBr pellets using an ATLI Mattson Genesis Series FTIR
spectrophotometer. Mass spectrometry studies were performed
by the Mass Spectrometry Facility, and elemental analyses
were performed by P. Borda of the Microanalyis Facility, at
the University of British Columbia.
P r ep a r a tion of Ru Cl2(d p p bO)(bip y) (7). NEt3 (0.08 mL,
0.57 mmol) was added to a stirred solution of cis-RuCl2(dppb)-
(bipy) (5) (44 mg, 0.058 mmol) in MeOH (15 mL) in air, and
the resulting solution was stirred at rt for 22 h, when the
solution changed from orange to dark red. The solvent was
removed under vacuum, and the residue was taken up in
CH2Cl2 (2 mL). Addition of Et2O (25 mL) precipitated the
product that was collected by filtration, washed with Et2O (4
× 2 mL), and then dried in vacuo. Yield: 35 mg (77%). Anal.
Calcd for C38H36N2Cl2OP2Ru: C, 59.23; H, 4.71; N, 3.64.
Found: C, 59.26; H, 4.82; N, 3.80%. 31P{1H} NMR (CDCl3): δ
P r ep a r a tion of [Ru Cl(BINAP O)(bip y)]P F 6 (3‚P F 6). An
orange solution of cis-RuCl2((R)-BINAP)(bipy) (1) (49 mg, 0.051
mmol) in MeOH (6 mL) was stirred in air for 14 days at rt,
when the solution became deep red. Solid NH4PF6 (85 mg, 0.52
mmol) was added to the solution, and the mixture stirred for
5 h. The solvent was removed in vacuo, and the dark red
residue then dissolved in CH2Cl2 (5 mL) and filtered through
Celite with washings of CH2Cl2 (4 × 4 mL). The filtrate was
concentrated under vacuum to ∼5 mL, and the product was
precipitated by addition of Et2O (10 mL) and hexanes (15 mL),
collected by filtration, washed with hexanes (2 × 3 mL) and
Et2O (4 × 3 mL), and dried in vacuo. Yield (as a mixture of
PF6 salts of isomers 3a and 3b): 40 mg (73%). Anal. Calcd for
1
53.4 s (PIII), 32.2 s (PV). H NMR (CDCl3): δ 0.90-2.52 (br m,
8H, CH2), 6.70-7.80 (br m, 26H: 20H for Ph protons, and 6H
for H3/ 3′-H5/ 5′ of bipy), 8.12 (m, 1H, H6 of bipy), 8.91 (m, 1H,
H6′ of bipy). IR (KBr, cm-1): ν(PO) 1121 (m). UV-vis
(CH2Cl2): 494 [4200], 344 [5000].
P r ep a r a tion of Ru Cl2(d p p bO)(p h en ) (8). Compound 8
was prepared in a manner similar to that used for 7, using
cis-RuCl2(dppb)(phen) (6) (29 mg, 0.037 mmol) and NEt3 (0.05
mL, 0.036 mmol) in MeOH (15 mL). The mixture was stirred
in air for 18 h and then worked up as described for 7. Yield:
23 mg (76%). Anal. Calcd for C40H36N2Cl2OP2Ru: C, 60.46; H,
4.57; N, 3.52. Found: C, 59.38; H, 4.90; N, 3.64. Several
attempts to obtain a better microanalysis were unsuccessful.
Anal. Calcd for a monohydrate: C, 59.11; H, 4.71; N, 3.45.
31P{1H} NMR (CDCl3): δ 53.7 s (PIII), 32.0 s (PV). 1H NMR
(CDCl3): δ 1.00-2.50 (br m, 8H, CH2), 6.52-8.80 (br m, 27H:
20H for Ph protons and 7H for H2-H8 of phen), 9.43 (m, 1H,
H9 of phen). IR (KBr, cm-1): ν(PO) 1120 (m). UV-vis
(CH2Cl2): 490 [5,600], 456 [5,000] (sh).
C
54H40N2ClF6OP3Ru: C, 60.26; H, 3.75; N, 2.60. Found: C,
60.22; H, 3.76; N, 2.74. 31P{1H} NMR (CD2Cl2): for 3a , δ 69.8
1
s, 56.6 s, and for 3b, δ 62.7 s, 59.2 s; -144.0 m J PF ) 710. H
NMR (CD2Cl2): δ 4.20-10.20 (br m, BINAPO and bipy
protons). IR (KBr, cm-1): ν(PO) 1129 (w, 3a ) and 1150 (w, 3b),
ν(PF) 841. UV-vis (CH2Cl2): 422 [4,800]. LRMS [+LSIMS]:
931 (M+), 896 (M+ - Cl), 739 (M+ - Cl - bipy). X-ray quality,
orange crystals of 3a ‚PF6 were obtained by slow aerobic
evaporation of a CHCl3 solution of the product obtained from
the reaction of 1 with 1 equiv of AgPF6.
X-r a y Cr ysta llogr a p h y. Crystallographic data for 3a ‚PF6
and 4a ‚PF6 are summarized in Table 3. The structure of

Ru(II)-Bis(phosphine) Monoxide Complexes
Organometallics, Vol. 21, No. 22, 2002 4679
3a ‚PF6 that crystallized with two CHCl3 solvates was deter-
mined using data collected on a Rigaku/ADSC CCD diffrac-
tometer at -100 °C. The data, corrected for Lorentz and
polarization effects, were collected and processed,56 and the
structure was solved by direct methods and expanded using
Fourier techniques. Of 44 345 reflections collected, 11 493 were
unique (Rint ) 0.055); equivalent reflections were merged. The
final cycle of full-matrix least-squares refinement was based
on 11 466 observed reflections (I > 0/00σ(I)) and 685 variable
parameters. All non-hydrogen atoms were refined anisotropi-
cally; H atoms were included but not refined. All calculations
were performed using the teXsan crystallographic software
package.56a
refinement of C(13)-C(18) and C(25)-C(34), 43 restraints
(DELU and ISOR) were added. All calculations were performed
using the SHELXTL suite of programs.57
Ack n ow led gm en t. We thank J ohnson Matthey Ltd.
and Colonial Metals Inc. for loans of RuCl3‚3H2O, Dr.
S. King (formerly of Merck Research) for a gift of (R)-
BINAP, and the Natural Sciences and Engineering
Research Council of Canada for financial support. We
gratefully acknowledge the work of Dr. Victor G. Young,
J r. (X-ray Crystallographic Laboratory, University of
Minnesota) for the X-ray analysis of 4a ‚PF6.
The structure of 4a ‚PF6 that crystallized with an MeOH
solvate was determined from data collected on a Siemens
SMART Platform CCD diffractometer at -100 °C. Most non-
hydrogen atoms were located using a direct methods solution,
and several least squares/difference Fourier cycles were
performed to locate the remainder. All H atoms were placed
in ideal positions and refined as riding atoms with relative
isotropic displacement parameters. Of the 80 682 reflections
collected, 8740 were independent (Rint ) 0.0650). Due to the
high-symmetry Laue class, an investigation was performed to
show that the crystal was not twinned. The length of the c
cell constant led to repositioning of the CCD detector, setting
it at 8.0 cm to collect data in two swaths. The Flack x
parameter (0.02(4)) was used to identify the correct space
group (P43212) from its enantiomorph (P41212). To aid the
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal-
lographic data for 3a ‚PF6 and 4a ‚PF6, including positional and
thermal parameters, complete bond lengths and angles, aniso-
tropic displacement parameters, and ORTEP figures showing
the entire molecules with full numbering schemes. This
material is available free of charge via the Internet at
http://pubs.acs.org.
OM0205344
(56) (a) teXsan: Crystal Structure Analysis Package; Molecular
Structure Corporation: The Woodlands, TX, 1997. (b) d*TREK: Area
Detector Software; Molecular Structure Corporation: The Woodlands,
TX, 1997.
(57) SHELXTL-Plus, Version 5.0; Siemens Industrial Automation,
Inc.: Madison, WI, 1994.