Synthesis and transition metal chemistry of a bridging diphosphinite,1,4 bis(diphenylphosphinoxy)benzene

Article abstract of DOI:10.1016/j.jorganchem.2011.08.008

Diphosphinite ligand, [Ph₂POC₆H₄OPPh ₂] (1), is obtained by reacting chloro diphenylphosphine, with 1,4-dihydroxy benzene in presence of triethylamine. Treatment of 1 with elemental sulfur or selenium resulted in the formation of bis(chalcogenide) derivatives, [Ph₂(E)POC₆H₄OP(E)Ph₂] (2, E = S; 3, E = Se) in almost quantitative yield. The binuclear complex [{(η⁶-p-cymene)RuCl₂}₂(Ph ₂POC₆H₄OPPh₂)] (4) is produced in the reaction between [Ru(η⁶-p-cymene)Cl₂]₂ and diphosphinite 1. Similarly the reaction of 1 with [Rh(COD)Cl]₂ afforded a binuclear complex [{(COD)RhCl}₂(Ph₂POC ₆H₄OPPh₂)] (5), whereas the macrocyclic complex [{(CO)RhCl}(Ph₂POC₆H₄OPPh₂)] ₂ (6) is isolated in the reaction of 1 with 0.5 equiv of [RhCl(CO)₂]₂. Compound 1 on treatment with [Pd(COD)Cl ₂] or [PdCl₂(SMe₂)₂] in 1:1 molar ratio produced the chloro-bridged binuclear complex [{(PPh₂O)Pd(μ- Cl)(PPh₂OH)}₂] (7) through P-O bond cleavage. Treatment of 1 with two equivalents of CuI in dichlormethane/acetonitrile (1:1) afforded a coordination polymer, [{Cu₂(μ-I)₂(Ph ₂POC₆H₄OPPh₂)}_∞] (8) in moderate yield. The binuclear complex, [{AuCl}₂(μ-Ph ₂POC₆H₄OPPh₂)] (9) is obtained in the reaction of compound 1 with two equiv of AuCl(SMe₂), where the ligand exhibits bridged bidentate mode of coordination. The molecular structures of 1-4, and 6 are determined by X-ray diffraction studies.

Full text of DOI:10.1016/j.jorganchem.2011.08.008

Journal of Organometallic Chemistry 696 (2011) 3616e3622
Contents lists available at SciVerse ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and transition metal chemistry of a bridging diphosphinite,
1,4 bis(diphenylphosphinoxy)benzene
,
a
a
b
Maravanji S. Balakrishnaa , D. Suresh , Pawan Kumar , Joel T. Mague
*
a Phosphorus Laboratory, Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, India
b Department of Chemistry, Tulane University, New Orleans, LA 70118, USA
a r t i c l e i n f o
a b s t r a c t
Article history:
Diphosphinite ligand, [Ph2POC6H4OPPh2] (1), is obtained by reacting chloro diphenylphosphine, with
1,4-dihydroxy benzene in presence of triethylamine. Treatment of 1 with elemental sulfur or selenium
resulted in the formation of bis(chalcogenide) derivatives, [Ph2(E)POC6H4OP(E)Ph2] (2, E ¼ S; 3, E ¼ Se)
Received 2 July 2011
Received in revised form
29 July 2011
in almost quantitative yield. The binuclear complex [{(
produced in the reaction between [Ru(
h
6-p-cymene)RuCl2}2(Ph2POC6H4OPPh2)] (4) is
Accepted 14 August 2011
h
6-p-cymene)Cl2]2 and diphosphinite 1. Similarly the reaction of 1
with [Rh(COD)Cl]2 afforded a binuclear complex [{(COD)RhCl}2(Ph2POC6H4OPPh2)] (5), whereas the
macrocyclic complex [{(CO)RhCl}(Ph2POC6H4OPPh2)]2 (6) is isolated in the reaction of 1 with 0.5 equiv
of [RhCl(CO)2]2. Compound 1 on treatment with [Pd(COD)Cl2] or [PdCl2(SMe2)2] in 1:1 molar ratio
Keywords:
Bis(phosphinite)
Bridging coordination
Rhodium(I) macrocycle
Ruthenium(II)
Palladium(II)
produced the chloro-bridged binuclear complex [{(PPh2O)Pd(
cleavage. Treatment of 1 with two equivalents of CuI in dichlormethane/acetonitrile (1:1) afforded
a coordination polymer, [{Cu2( -I)2(Ph2POC6H4OPPh2)}N] (8) in moderate yield. The binuclear complex,
[{AuCl}2( -Ph2POC6H4OPPh2)] (9) is obtained in the reaction of compound 1 with two equiv of
m-Cl)(PPh2OH)}2] (7) through PeO bond
m
Copper(I)
m
AuCl(SMe2), where the ligand exhibits bridged bidentate mode of coordination. The molecular struc-
tures of 1e4, and 6 are determined by X-ray diffraction studies.
Ó 2011 Elsevier B.V. All rights reserved.
1. Introduction
chemistry by preparing tetra- and hexaphosphonite ligands
[29e33]. As a part of our interest in phosphorus-based ligands and
The interest in making new bidentate ligands is two-fold: one is
to make chelate complexes especially with platinum metals
because of their usefulness in homogeneous catalysis [1e10].
Secondly, the bidentate ligands, capable of bridging two metal
centers are equally interesting because of their ability to form di-,
tri-, tetra or polynuclear complexes and, are most sought after
ligand systems in supramolecular chemistry [11e23]. Rigid
nitrogen-donor ligands such as 4,40-bipyridine, 4,40-dibenzonitrile,
pyrazine or triazenes have been extensively used as linkers in
coordination chemistry to generate multidimensional, multi-
organic materials with diverse properties [24e28]. In this context,
it would be interesting to make analogous phosphorus-based
bridging ligands as they are easily tunable in terms of both elec-
tronic and steric properties. Such ligands would be even better in
molecular assembly as they can stabilize even the low-valent
their coordination chemistry [34e36], we describe herein the
synthesis of a bis(phosphinite) ligand and its transition metal
complexes.
2. Results and discussion
2.1. Synthesis of ligand and its chalcogen derivatives
The reaction of 1,4-dihydroxy benzene with two equivalents of
chloro diphenylphosphine in diethyl ether in the presence of trie-
thylamine afforded the bis(phosphinite) ligand [Ph2POC6H4OPPh2]
(1) in good yield. Treatment of bis(phosphinite) 1 with two
equivalents of elemental sulfur or gray selenium under refluxing
condition resulted in the formation of bis(chalcogenide) derivatives
[Ph2(E)POC6H4OP(E)Ph2] (2, E ¼ S; 3, E ¼ Se) as shown in Scheme 1.
The bis(phosphinite) 1 is a white crystalline solid, moderately
stable toward air and moisture, whereas the sulfide and selenide
derivatives (2 and 3) are highly stable and soluble in most of the
common organic solvents. The 31P{1H} NMR spectra of compounds
1e3 consist of single resonances at 110.5, 80.3 and 85.1 ppm,
transition metals because of their flexibility in
s-donor and
p-acceptor abilities. Recently we have extended the scope of this
* Corresponding author. Tel.: þ91 22 2576 7181; fax: þ91 22 2576 7152/2572
3480.
1
E-mail addresses: krishna@chem.iitb.ac.in, msb_iitb@yahoo.com(M.S.Balakrishna).
respectively. The bis(selenide) 3 shows a JPSe coupling of 824 Hz.
0022-328X/$ e see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2011.08.008

M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
3617
Ph2P
PPh2
O
E
Et 3N, Et2O
0-25 oC
HO
OH
O
2 E / Toluene
O
O
PPh2
Δ
E
, 12-16 h
Ph2P
+
1
E = S
Se
2
2 PPh2Cl
3
Scheme 1. Synthesis and derivatization of diphosphinite 1.
The 1H NMR spectra of compounds 1e3 show multiplets in the
region of 7.58e7.15 ppm for eP(C6H5)2 protons and the
(eOC6H4Oe) protons appear around 6.99e6.78 ppm. The molecular
structures of compounds 2 and 3 were confirmed by single crystal
X-ray diffraction studies.
Ph2POH/Ph2PCl in a mixture of water and acetone [39]. The 31P{1H}
NMR spectrum of 7 shows a single resonance at 76.7 ppm. Inter-
action of bis(phosphonite) 1 with two equivalents of CuI in
dichlormethane/acetonitrile (1:1) afforded a coordination polymer,
[{Cu2(
Treatment of 1 with [AuCl(SMe2)] in dichloromethane yields
a binuclear gold(I) complex [{AuCl}2( -Ph2POC6H4OPPh2)] (9) in
m-I)2(Ph2POC6H4OPPh2)}N] in moderate yield (Scheme 3).
m
2.2. Transition metal chemistry of bis(phosphinite) ligand
excellent yield. The copper(I) coordination polymer is soluble only
in hot dimethyl sulphoxide while the highly soluble binuclear
gold(I) complex is found to be light sensitive. The 31P{1H} NMR
spectra of 8 and 9 show singlets at 90.8 and 112.9 ppm, respectively.
The 1H NMR spectral data and the elemental analyses data of
complex 7 are consistent with the proposed structure. The molec-
ular structure of 7 was further confirmed by X-ray diffraction study.
Treatment of [Ru(
1:1 molar ratio in dichloromethane resulted in the formation of
a binuclear complex [{(
6-p-cymene)RueCl2}2(Ph2POC6H4OPPh2)]
h
6-p-cymene)Cl2]2 with bis(phosphonite) 1 in
h
(4) as orangeered crystalline solid. The 31P{1H} NMR spectrum of 4
shows a single resonance at 113.6 ppm with a coordination shift of
3.1 ppm. The signals at 2.75 (septet), 2.15 (singlet) and 1.59
(doublet) ppm in the 1H NMR spectrum confirm the presence of
p-cymene group. The EI mass spectrum of 4 shows molecular ion
peak at 1055.6 corresponds to [MeCl]. The reaction of equimolar
ratio of 1 with [Rh(COD)Cl]2 in dichloromethane yielded a binuclear
complex [{(COD)RhCl}2(Ph2POC6H4OPPh2)] (5) in good yield. Slow
addition of [RhCl(CO)2]2 to 1 in 1:2 molar ratio produced a binu-
clear complex, [{(CO)RhCl}(Ph2POC6H4OPPh2)]2 (6) as shown in
Scheme 2. The 31P{1H} NMR spectra of rhodium(I) complexes 5 and
2.3. Molecular structures of compounds 1e4, and 6
Perspective views of the molecular structures of 1e4 and 6 along
with atom labeling schemes are shown in Figs. 1e5, while the
selected bond lengths (Å) and bond angles (ꢁ) are given as caption
to figures. The details of the structure determination are given in
Table 1.
Slow evaporation of dichloromethane/petroleum ether mixture
kept at room temperature yielded the colorless crystals of 1 suitable
for single crystal X-ray diffraction study. The ligand 1 possesses
crystallographically imposed C2 symmetry in which the asym-
metric unit contains half the molecule of 1. Further it crystallizes in
Triclinic crystal system with the space group P1 (No. 02). One of the
phenyl rings on phosphorus is almost perpendicular to the plane of
hydroquinone moiety. The phosphorus atoms are in a distorted
tetrahedral geometry with maximum deviation shown by the
O1eP1eC1 bond where the bond angle is 97.20(12)ꢁ.
1
6 show doublets centered at 122.9 and 121.1 ppm with the JRhP
couplings of 180 and 140 Hz, respectively. The relatively low 1JRhP is
attributed to the trans disposition of the phosphorus centers which
confirms the formation of a binuclear complex 6. The rhodium(I)
complex 6 shows nCO at 1990 cmꢀ1. The molecular structures of
ruthenium (4) and rhodium (6) complexes were confirmed by
X-ray diffraction studies.
The reaction of bis(phosphonite)
[PdCl2(SMe2)2] in 1:1 molar ratio resulted in the formation of
a chloro-bridged binuclear complex [{(PPh2O)Pd( -Cl)(PPh2OH)}2]
1 with [Pd(COD)Cl2] or
m
(7) [37]. The reaction probably proceeds via the moisture assisted
PeO bond cleavage to form the intermediate [Cl2Pd(PhPOH)2]
which on elimination of HCl gives the chloro-bridged binuclear
complex 7 with interesting chemical reactivity [38]. Previously, the
complex 7 was obtained in the reaction between K2PdCl4 and
Very similar to the ligand 1, the chalcogen derivatives also
contain crystallographically imposed C2 symmetry. The bis(sulfide)
2 crystallizes in monoclinic crystal system with the space group
P21/c (No. 14). The phosphorus atoms are in a distorted tetrahedral
geometry being bound to one sulfide, one oxygen and two carbon
Cl
PPh2
Ph2P
O
Rh
PPh2
O
O
O
Ph2
P
Cl
CO
Rh
Rh
[Rh(COD)Cl]2
DCM, rt 2 h
O
[Rh(CO)2Cl]2
DCM, rt 4 h
O
P
Cl
Ph2
5
1
CO
O
O
Ph2P
P
μ
Ph 2P
Rh
Cl
[(p-cymene)Ru( -Cl)Cl]2
DCM, r t 4 h
Ph2
6
Ph2
P
O
Cl
Ru
Ru
O
Cl
P
Cl
Ph2
Cl
4
Scheme 2. Ruthinum(II) and rhodium(I) complexes of diphosphinite 1.

3618
M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
PPh2
O
Cu
I
PPh2
O
I
Ph 2
P
O
OH
OH
Cl
Cl
CuI
[Pd(COD)Cl2]
DCM, rt 4 h
Ph2P
Cu
Pd
DCM/CH3CN, rt 4 h
P
Ph2
8
8
O
1
[AuCl(SMe2)]
DCM, r t 2 h
Ph2P
Ph2
P
Ph 2
Ph2
Cl
P
O
P
Cl
O
O
Au
Au
Cl
H
O
Pd
Pd
O
H
P
O
P
Cl
7
P
Ph2
9
Ph2
Ph2
Scheme 3. Palladium(II), copper(I) and gold(I) complexes of diphosphinite 1.
atoms of phenyl groups. The largest deviation from the ideal
geometry is reflected by the O1eP1eC4 and S1eP1eC4 bonds
whose bond angles are 103.28(6)ꢁ and 114.76(5)ꢁ, respectively. The
P1eS1 bond length is 1.9283(6) Å which is shorter than the same
present in Ph3P]S (PeS, 1.9355(4) Å). This is due to the electron
withdrawing nature of phosphorus atoms which enhance the back
bonding and thus shortening the PeS bond distance.
The bis(selenide) 3 is isomorphous to bis(sulfide) derivative 2
which is crystallized in monoclinic crystal system with space group
P21/c (No. 14). The PeSe (2.0792(4) Å) bond distance is shorter than
the Ph3P]Se (PeSe, 2.106(1) Å) as expected. The other bond
parameters of 3 follow the same pattern as that of 2.
distances range from 2.187(3)
Å
(Ru2eC47) to 2.262(4) Å
(Ru2eC44) in which the RueC bonds (Ru1eC18, 2.239(3) Å) trans to
phosphine are longer than those trans to the chlorine atoms
(Ru1eC15, 2.209(3) Å) and this is essentially due to the steric bulk
of phosphorus substituents which lifts the carbon atoms close to
phosphorus slightly upward. The RueP bond lengths (Ru1eP1,
2.3185(9) Å and Ru2eP2, 2.3055(9)Å) vary slightly as do the PeO
bond lengths (P1eO3, 1.635(2) Å and P2eO4, 1.629(2) Å).
The molecular structure of 6 is shown in Fig. 5. The structure
consists of two trans-{Rh(CO)Cl} units bridged by two bis(phos-
phinite) ligands to form a centro-symmetric 18-membered mac-
rocycle with rhodium centers in slightly distorted square planar
environments. The RheP1 and RheP2 distances are 2.2977(9) and
2.3032(9) Å, respectively. The Cl1eRh1eC31 (175.76(11)ꢁ) and
P1eRh1eP2 (174.82(3)ꢁ) bond angles indicate the slight distortion
in the square planar geometry around rhodium centers. The
Cl1eRh1eP1 and Cl1eRh1eP2 bond angles are 89.97(3)ꢁ and
88.91(3)ꢁ, respectively.
The orangeered crystals of 4 suitable for single crystal X-ray
diffraction study were obtained by slow evaporation of dichloro-
methane/petroleum ether mixture at room temperature. The
asymmetric unit contains one molecule of 4 and a distorted
dichloromethane molecule as a solvent of crystallization. Each
ruthenium center contain a p-cymene group coordinated in a h6
-
fashion, a phosphorus center and two chloride atoms to form
a typical three-legged “piano-stool” structure. The Cl1eRu1eP1
and Cl2eRu1eP1 bond angles are 87.59(3)ꢁ and 90.74(3)ꢁ, respec-
tively. The Cl1eRu1eCl2 bond angle is 86.27(3)ꢁ. The RueC bond
The molecular structure of 7 (Fig. 6) is identical to that of the
structure reported previously by Priya et al. [37] and others [40].
3. Conclusions
Bis(phosphonite)
1 is a typical bidentate ligand showing
invariably the bridged bidentate mode of coordination. Reactions of
1 with chalcogens afford the corresponding bis(chalcogenide)
derivatives. The coordination behavior of bis(phosphonite) ligand
was explored with various transition metal precursors. The ligand
Fig. 2. Perspective view of molecular structure of 2. Thermal ellipsoids are drawn at
50% probability level. All hydrogen atoms were omitted for clarity. Selected bond
lengths (Å): S1eP1, 1.9283(6); P1eO1, 1.6173(11); P1eC4, 1.8005(16); P1eC10,
1.7961(15); O1eC1, 1.4068(17). Selected bond angles (ꢁ): S1eP1eO1, 115.89(4);
S1eP1eC4, 114.76(5); S1eP1eC10, 114.82(5); O1eP1eC4, 103.28(6); O1eP1eC10,
99.26(6); C4eP1eC10, 107.08(7).
Fig. 1. Perspective view of molecular structure of 1. Thermal ellipsoids are drawn at
50% probability level. All hydrogen atoms were omitted for clarity. Selected bond
lengths (Å): P1eO1, 1.662(2); P1eC1, 1.826(3); P1eC7, 1.834(3); O1eC13, 1.394(3).
Selected bond angles (ꢁ): O1eP1eC1, 97.19(12); O1eP1eC7, 101.95(12); C1eP1eC7,
99.36(14).

M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
3619
Fig. 3. Perspective view of molecular structure of 3. Thermal ellipsoids are drawn at
50% probability level. All hydrogen atoms were omitted for clarity. Selected bond
lengths (Å): Se1eP1, 2.0792(4); P1eO1, 1.6218(10); P1eC4, 1.8025(15); P1eC10,
1.7981(14); O1eC1, 1.4075(17). Selected bond angles (ꢁ): Se1eP1eO1, 115.54(4);
Se1eP1eC4, 114.98(5); Se1eP1eC10, 114.67(5); O1eP1eC4, 103.66(6); O1eP1eC10,
99.51(6); C4eP1eC10, 106.77(6).
Fig. 5. Perspective view of molecular structure of 6. Thermal ellipsoids are drawn at
50% probability level. All hydrogen atoms and the solvated dichloromethane molecules
were omitted for clarity. Selected bond lengths (Å): Rh1eCl1, 2.3609(8); Rh1eC31,
1.812(3); Rh1eP1, 2.2977(9); Rh1eP2, 2.3032(9); P1eO1, 1.644(2); P1eC1, 1.824(3);
P1eC7, 1.812(3); P2eO2, 1.640(2); P2eC22, 1.812(3); P2eC16, 1.813(3). Selected bond
angles (ꢁ): Cl1eRh1eC31, 175.76(11); Cl1eRh1eP1, 89.97(3); Cl1eRh1eP2, 88.91(3);
P1eRh1eP2, 174.82(3); P2eRh1eC31, 92.27(11); P1eRh1eC31, 88.50(11).
exhibits bridged bidentate mode of coordination with Ru(II), Rh(I)
and Au(I) derivatives to give binuclear complexes. The cleavage of
PeO bond had occurred during the reaction with Pd(II) derivative
to form a chloro-bridged dimeric complex. Presently we are trying
to use these ligands along with pyridyl ligands to form 2D and 3D
coordination polymers and high nuclearity supramolecules for
their possible utility as catalysts in appropriate organic
transformations.
Cl2Ru}2] [44], and [AuCl(SMe2)] [45] were prepared according to
the published procedures.
4. Experimental section
4.2. Spectroscopy
The 1H and 31P{1H} NMR (
d in ppm) spectra were obtained on
4.1. General procedures
a Varian VXR 400 spectrometer operating at frequencies of 400 and
162 MHz respectively. The tetramethylsilane and 85% H3PO4 were
used as an internal and external standards for 1H and 31P{1H} NMR
respectively. Positive shifts lie downfield of the standard in all the
cases. Electro-spray ionization (EI) mass spectrometry experiments
were carried out by using Waters Q-Tof micro-YA-105. Microanal-
yses were carried out on a Carlo Erba Model 1106 elemental
analyzer. Infrared spectra were recorded on a Nicolet Impact 400
FTIR instrument as a KBr disc. Melting points of all compounds
were determined on Veego melting point apparatus and were
uncorrected.
All experimental manipulations were carried out under dry
nitrogen or argon atmosphere using standard Schlenk techniques
unless otherwise stated. Solvents were dried and distilled prior to
use by conventional methods. The precursors [(COD)2PdCl2] [41],
[{Rh(m-Cl)(CO)2}2] [42], [{Rh(m-Cl)(COD)}2] [43], [{(h
6-p-cymene)
4.2.1. Synthesis of [Ph2POC6H4OPPh2] (1)
The chloro diphenylphosphine (2.49 g, 11.285 mmol) in diethyl
ether (10 mL) was added dropwise to mixture of 1,4-dihydroxy
benzene (0.621 g, 5.642 mmol) and triethylamine (1.142 g,
11.285 mmol) in 30 mL of diethyl ether over a period of 15 min with
constant stirring at 0 ꢁC. The reaction mixture was allowed to warm
to room temperature and the stirring was continued for 16 h. The
hydrochloride salt formed was filtered through frite containing
celite and all volatiles were removed under vacuum and recrys-
tallized from dichloromethane and petroleum ether to afford 1 as
white crystalline compound. Yield: 76% (2.052 g, 4.288 mmol). Mp:
128e130 ꢁC. Anal. Calcd. for C30H24O2P2: C, 75.31; H, 5.06%. Found:
C. 75.49; H, 5.22%. 1H NMR (400 MHz, CDCl3,
phenyl, 20H), 6.99 (s, eC6H4e, 4H). 31P{1H} NMR (161.8 MHz, CDCl3,
): 110.5 (s).
d): 7.58e7.37 (m,
d
Fig. 4. Perspective view of molecular structure of 4. Thermal ellipsoids are drawn at
50% probability level. All hydrogen atoms and the solvated dichloromethane molecules
were omitted for clarity. Selected bond lengths (Å): Ru1eCl1, 2.3995(9); Ru1eCl2,
2.4128(9); Ru1eP1, 2.3185(9); Ru1eC14, 2.214(4); P1eO3, 1.635(2); P1eC1, 1.824(3);
P1eC7, 1.817(3). Selected bond angles (ꢁ): Cl1eRu1eCl2, 86.27(3); Cl1eRu1eP1,
87.59(3); Cl1eRu1eC14, 152.30(10); Cl1eRu1eC17, 90.27(8) Cl2eRu1eP1, 90.74(3);
P1eO3eC23, 123.8(2).
4.2.2. Synthesis of [Ph2(S)POC6H4OP(S)Ph2] (2)
A mixture of 1 (0.192 g, 0.401 mmol) and elemental sulfur
(0.026 g, 0.802 mmol) in 10 mL of toluene was heated under reflux
for 16 h. The reaction mixture was allowed to cool to room
temperature and all the volatiles were removed under vacuum. The

3620
M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
Table 1
Crystallographic Data for 1e4, and 6.
1
2
3
4
6
Formula
fw
C30H24O2P2
478.43
C30H24O2P2S2
542.55
C30H24O2P2Se2
636.35
C51H54Cl6O2P2Ru2
1175.72
C64H52Cl6O6P4Rh2
1459.46
Crystal system
Space group
a, Å
b, Å
c, Å
Triclinic
P-1 (No. 2)
10.261(3)
10.883(3)
11.917(3)
87.926(4)
87.763(4)
65.648(4)
1211.2(6)
2
Monoclinic
P21/c (No. 14)
9.0992(6)
10.3873(7)
14.3560(10)
90
104.2660(10)
90
1315.03(15)
2
Monoclinic
P21/c (No. 14)
9.1027(6)
10.4872(7)
14.4430(10)
90
104.6350(10)
90
1334.02(16)
2
Monoclinic
P21/c (No. 14)
22.5307(9)
16.0097(7)
14.3400(6)
90
107.8950(10)
90
4922.3(4)
4
Triclinic
P1 (No. 1)
9.0041(8)
11.7680(10)
15.3110(10)
74.3880(10)
88.3540(10)
77.0890(10)
1522.2(2)
1
a
, deg
, deg
b
g
, deg
V, Å3
Z
rcalc, g cmꢀ3
1.312
0.206
1.370
0.351
1.584
2.918
1.587
1.044
0.796
0.963
m
(MoK
a
), mmꢀ1
F (000)
500
564
636
2384
368
Crystal size (mm)
T, K
0.08 ꢂ 0.12 ꢂ 0.27
0.08 ꢂ 0.15 ꢂ 0.17
0.09 ꢂ 0.13 ꢂ 0.14
0.03 ꢂ 0.09 ꢂ 0.09
0.05 ꢂ 0.09 ꢂ 0.09
100
100
100
100
100
2
q
range, deg
2.0, 27.8
36,029
2.3e28.4
22,413
2.3e28.8
23,229
1.6e28.0
43,065
2.6e28.0
26,380
Total no. reflns
No. of indep. Reflns
R1a
10,681 [Rint ¼ 0.028]
3274 [Rint ¼ 0.028]
3449 [Rint ¼ 0.034]
11,619 [Rint ¼ 0.050]
7276 [Rint ¼ 0.042]
0.0614
0.0333
0.0220
0.0402
0.0392
b
wR2
0.1967
1.48
0.0926
1.023
0.0595
1.072
0.0886
1.016
0.1007
1.04
GOF (F2)
a
R ¼ SjjFoj e jFcjj/SjFoj.
P
P
wR2 ¼ f½ wðFo2 ꢀ Fc2Þ= wðFo2Þ2ꢃg1=2
;
w ¼ 1=½s2ðFo2 þ ðxPÞ2Þꢃ where P ¼ ðFo2 þ 2Fc2Þ=3.
b
residue was extracted with dichloromethane (10 mL) and filtered
off. The filtrate was concentrated to 4 mL and layered with petro-
leum ether (2 mL); kept at room temperature for a day to give 2 as
white crystalline compound. Yield: 94% (0.205 g, 0.377 mmol). Mp:
184e186 ꢁC. Anal. Calcd. for C30H24O2P2S2: C, 66.41; H, 4.46; S,
11.82%. Found: C. 66.53; H, 4.22; S,11.95%. 1H NMR (400 MHz, CDCl3,
6.85 (s, eC6H4e, 4H). 31P{1H} NMR (161.8 MHz, CDCl3,
1JPeSe ¼ 824 Hz.
d): 85.1 (s),
4.2.4. Synthesis of [{(
h
6-p-cymene)Cl2Ru}2(Ph2POC6H4OPPh2)] (4)
6-p-cymene)]2
A dichloromethane (5 mL) solution of [Cl2Ru(
h
(0.033 g, 0.054 mmol) was added dropwise to 1 (0.026 g,
0.054 mmol) in dichloromethane (5 mL) for about 2 min. The
reaction mixture was stirred for 6 h at room temperature. The
clear red colored solution was concentrated to 6 mL, layered with
3 mL of petroleum ether and kept at room temperature for 2 days
to afford 4 as red crystalline compound. Yield: 83% (0.049 g,
0.045 mmol). Mp: 164e166 ꢁC (dec). Anal. Calcd. for C50H52
O2P2Ru2Cl4: C, 55.05; H,4.80%. Found: C. 55.28; H, 4.69%. 1H NMR
d
): 7.68e7.15 (m, phenyl, 20H), 6.78 (s, eC6H4e, 4H). 31P{1H} NMR
(161.8 MHz, CDCl3, ): 80.3 (s).
d
4.2.3. Synthesis of [Ph2(Se)POC6H4OP(Se)Ph2] (3)
This was synthesized by a procedure similar to that of 2, using 1
(0.192 g, 0.401 mmol) and elemental selenium powder (0.063 mg,
0.802 mmol). Yield: 88% (0.224 g, 0.353 mmol). Mp: 196e198 ꢁC.
Anal. Calcd. for C30H24O2P2Se2: C, 56.62; H,3.80%. Found: C. 56.49;
(400 MHz, CDCl3,
4H), 5.25 (d, JHH
d
): 7.95e7.32 (m, phenyl, 20H), 6.72 (s, eC6H4e,
6.0 Hz, Cymene phenyl, 4H), 5.16 (d,
H, 3.72%. 1H NMR (400 MHz, CDCl3,
d
): 7.55e7.17 (m, phenyl, 20H),
¼
JHH ¼ 6.0 Hz, Cymene phenyl, 4H), 2.75 (septet, CH, 2H), 2.15 (s,
CH3, 6H), 1.59 (d, JHH ¼ 12.8 Hz, CH3, 12H). 31P{1H} NMR
(161.8 MHz, CDCl3, d): 113.6 (s).
4.2.5. Synthesis of [{Rh(COD)Cl}2(Ph2POC6H4OPPh2)] (5)
To a solution of 1 (0.018 g, 0.037 mmol) in dichloromethane
(5 mL) added dropwise a solution of [Rh(COD)Cl]2 (0.018 g,
0.037 mmol) also in dichloromethane (5 mL) at room temperature.
The stirring was continued for further 6 h. The yellow colored
solution was concentrated to 4 mL, layered with 2 mL of petroleum
ether and kept at ꢀ25 ꢁC to afford 5 as yellow crystalline
compound. Yield: 73% (0.026 g, 0.026 mmol). Mp: 140e142 ꢁC
(dec). Anal. Cal. for C46H48O2P2Rh2Cl2: C, 56.86; H, 4.98%. Found: C.
56.55; H, 4.82%. 1H NMR (400 MHz, CDCl3, d): 7.86e6.94 (m, phenyl,
20H), 6.69 (s, eC6H4e, 4H), 5.59 (br s, CH, 4H), 2.35 (d, JHH ¼ 18.8 Hz,
CH2, 8H). 31P{1H} NMR (161.8 MHz, CDCl3,
1JRhP ¼ 180.6 Hz).
d): 122.9 (d,
4.2.6. Synthesis of [{(Rh(CO)Cl)}(Ph2POC6H4OPPh2)]2 (6)
A dichloromethane (5 mL) solution of [RhCl(CO)2]2 (0.014 g,
0.035 mmol) was added dropwise to a well-stirred dichloro-
methane solution (5 mL) of 1 (0.034 g, 0.071 mmol) at room
temperature. The reaction mixture was stirred for 4 h. The solution
was concentrated to 5 mL under reduced pressure, layered with
Fig. 6. The molecular structure of [{(PPh2O)Pd(m-Cl)(PPh2OH)}2] (7). All hydrogen
atoms and the solvated dichloromethane molecules were omitted for clarity. Thermal
ellipsoids are drawn at 50% probability level.

M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
3621
3 mL of petroleum ether, and placed at room temperature to get 6
as pale yellow crystalline compound. Yield: 82% (0.037 g,
0.057 mmol). Mp: 232e234 ꢁC (dec). Anal. Cal. for C31H24O3PRhCl:
C, 60.65; H, 3.94%. 1H NMR (400 MHz, CDCl3, d): Found: C. 60.48; H,
positions (CeH ¼ 0.95 Å (aromatic rings) or 0.98 Å (methyl groups))
and included as riding contributions with isotropic displacement
parameters 1.2 (aromatic rings) or 1.5 (methyl groups) times those
of the attached non-hydrogen atoms.
3.62%. 1H NMR (400 MHz, CDCl3,
d): 7.86e7.84 (m, phenyl, 10H),
7.41e7.40 (m, phenyl, 10H), 6.71 (s, eC6H4e, 4H). 31P{1H} NMR
Acknowledgments
(161.8 MHz, CDCl3,
d
): 121.1 (d, 1JRhP ¼ 140.4 Hz).
We thank the Department of Science and Technology (DST),
New Delhi, for financial support of this work through grant SR/S1/
IC-17/2010. We also thank the Department of Chemistry Instru-
mentation Facilities, Bombay, for spectral and analytical data and
J. T. M thanks the Louisiana Board of Regents for purchase of the
CCD diffractometer and the Chemistry Department of Tulane
University for support of the X-ray laboratory.
4.2.7. Synthesis of [{(Ph2PO)Pd(m-Cl)(PPh2OH)}2] (7)
The pale yellow colored solution of [Pd(COD)Cl2] (0.030 g,
0.105 mmol) in dichloromethane (5 mL) was added dropwise to 1
(0.050 g, 0.105 mmol) also in dichloromethane (5 mL) for about
3 min. The reaction mixture was stirred for 4 h at room tempera-
ture. The clear yellow colored reaction mixture was concentrated to
5 mL, layered with 2 mL of petroleum ether and kept at room
temperature for a day to afford compound 7 as yellow crystals.
Yield: 73% (0.038 g, 0.034 mmol). Mp: 188e190 ꢁC (dec). Anal. Cal.
for C48H42O4P4Pd2Cl2: C, 52.87; H, 3.88%. Found: C. 52.68; H, 3.79%.
Appendix A. Supplementary material
CCDC 830366, 830367, 830368, 830369 and 830370 contain the
supplementary crystallographic data for 1e4 and 6. These can be
obtained free of charge from the Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
1H NMR (400 MHz, DMSO-d6,
(s, eC6H4e, 4H). 31P{1H} NMR (161.8 MHz, DMSO-d6,
d
): 7.92e7.22 (m, phenyl, 20H), 6.71
): 76.7(s).
d
4.2.8. Synthesis of copper [Cu2I2(Ph2POC6H4OPPh2)] (8)
To a solution of 1 (0.031 g, 0.065 mmol) in dichloromethane
(5 mL) added dropwise CuI (0.024 g, 0.129 mmol) in acetonitrile
(5 mL) at room temperature. The reaction mixture was stirred for
further 4 h. During which time the product get precipitated and
separated by filtration. The product was washed several times with
diethyl ether and dried under vacuum to afford 8 as white crys-
talline solids. Yield: 68% (0.45 g, 0.034 mmol). Mp: >250 ꢁC (dec).
Anal. Cal. for C30H24O2P2Cu2I2: C, 41.92; H, 2.81%. Found: C. 41.63; H,
References
[1] J.F. Hartwig, Acc. Chem. Res. 41 (2008) 1534e1544.
[2] L.-C. Liang, Coord. Chem. Rev. 250 (2006) 1152e1177.
[3] P. Kuhn, D.S. Emeril, D. Matt, M.J. Chetcuti, P. Lutz, Dalton Trans. (2007)
515e528.
[4] P. Braunstein, J. Organomet. Chem. 689 (2004) 3953e3967.
[5] B. Punji, J.T. Mague, M.S. Balakrishna, J. Organomet. Chem. 691 (2006)
4265e4272.
[6] B. Punji, J.T. Mague, M.S. Balakrishna, Dalton Trans. (2006) 1322e1330.
[7] B. Punji, J.T. Mague, M.S. Balakrishna, Eur. J. Inorg. Chem. (2007) 720e731.
[8] M.S. Balakrishna, R. Venkateswaran, J.T. Mague, Dalton Trans. (2010)
11149e11162.
[9] Z. Guo, X. Guan, Z. Chen, Tetrahedron: Asymmetry 17 (2006) 468e473.
[10] H. Salem, L.J.W. Shimon, P.Y. Diskin, G. Leitus, Y. Ben-David, D. Milstein,
Organometallics 28 (2009) 4791e4806.
2.75%. 1H NMR (400 MHz, DMSO-d6,
d): 7.79e7.27 (m, phenyl, 20H),
6.69 (s, eC6H4e, 4H). 31P{1H} NMR (161.8 MHz, DMSO-d6,
d): 90.8
(br s).
4.2.9. Synthesis of gold [{AuCl}2(m-Ph2POC6H4OPPh2)] (9)
A dichloromethane (5 mL) solution of [AuCl(SMe2)] (0.027 g,
0.092 mmol) was added dropwise to a well-stirred dichloromethane
solution (5 mL) of 1 (0.022 g, 0.046 mmol) for about 2 min. The
reaction mixture was stirred for 4 h at room temperature. The
solution was concentrated to 5 mL under reduced pressure, layered
with 3 mL of petroleum ether and placed at room temperature to get
9 as white crystalline compound. Yield: 95% (0.041 g, 0.044 mmol).
Mp: 178e180 ꢁC (dec). Anal. Cal. for C30H24O2P2Au2Cl2: C. 38.19; H,
[11] M.S. Balakrishna, P.P. George, S.M. Mobin, Polyhedron 24 (2005) 475e480.
[12] P. McQuade, N.P. Rath, L. Barton, Inorg. Chem. 38 (1999) 5468e5470.
[13] P.A. Wegner, L.F. Evans, J. Haddock, Inorg. Chem. 14 (1975) 192e194.
[14] R.L. Keiter, K.M. Fasig, L.W. Cary, Inorg. Chem. 14 (1975) 201e203.
[15] B.P. Sullivan, T.J. Meyer, Inorg. Chem. 19 (1980) 752e755.
[16] F. Faraone, G. Bruno, S.L. Schiavo, G. Bombieri, J. Chem. Soc. Dalton Trans.
(1984) 533e538.
[17] A.A. Barney, P.E. Fanwick, C.P. Kubiak, Organometallics 16 (1997) 1793e1796.
[18] J.W. Benson, R.L. Keiter, E.A. Keiter, A.L. Rheingold, G.P.A. Yap, V.V. Mainz,
Organometallics 17 (1998) 4275e4281.
[19] S. Shimada, M.L. Rao, M. Tanaka, Organometallics 18 (1999) 291e293.
[20] D. Imhof, U. Burckhardt, K.-H. Dahmen, F. Joho, R. Nesper, Inorg. Chem. 36
(1997) 1813e1820.
[21] C.E. Anson, A.E. Fer, I. Issac, D. Fenske, O. Fuhr, P. Sevillano, C. Persau, D. Stalke,
J. Zhang, Angew. Chem. Int. Ed. 47 (2008) 1326e1331.
[22] G. Peli, M. Daghetta, P. Macchi, A. Sironic, L. Garlaschelli, Dalton Trans. 39
(2010) 1188e1190.
2.55%. Found: C. 38.35; H, 2.62%. 1H NMR (400 MHz, CDCl3,
d):
7.83e7.77 (m, phenyl, 10H), 7.61e7.53 (m, phenyl, 10H), 6.99 (s,
eC6H4e, 4H). 31P{1H} NMR (161.8 MHz, CDCl3, d): 112.9 (s).
4.3. X-ray crystallography
[23] D. Fenske, C.E. Anson, A.E. Fer, O. Fuhr, A. Ingendoh, C. Persau, C. Richert,
Angew. Chem. Int. Ed. 44 (2005) 5242e5246.
[24] H.W. Roesky, M. Andruh, Coord. Chem. Rev. 236 (2003) 91e119.
[25] S. Brase, Acc. Chem. Res. 37 (2004) 805e816.
[26] Y. Yamauchi, M. Yoshizawa, M. Akita, M. Fujita, J. Am. Chem. Soc. 132 (2010)
960e966.
[27] T. Kawamichi, Y. Inokuma, M. Kawano, M. Fujita, Angew. Chem. Int. Ed. 49
(2010) 2375e2377.
[28] M.-X. Li, Z.-X. Miao, M. Shao, S.-W. Liang, S.-R. Zhu, Inorg. Chem. 47 (2008)
4481e4489.
[29] C.Ganesamoorthy,M.S. Balakrishna,J.T.Mague,DaltonTrans. (2009)1984e1990.
[30] C. Ganesamoorthy, M.S. Balakrishna, Inorg. Chem. 48 (2009) 3768e3782.
[31] C. Ganesamoorthy, M.S. Balakrishna, J.T. Mague, H.M. Tuononen, Inorg. Chem.
47 (2008) 7035e7047.
[32] C. Ganesamoorthy, M.S. Balakrishna, J.T. Mague, J. Organomet. Chem. 694
(2009) 3390e3394.
[33] S. Rao, C. Ganesamoorthy, S. Mobin, M.S. Balakrishna, Dalton Trans. 40 (2011)
5841e5843.
Crystals of 1e4 and 6 were mounted in a CryoLoopÔ with a drop
of Paratone oil and placed in the cold nitrogen stream of the
KryoflexÔ attachment of the Bruker APEX CCD diffractometer. For
each, a full sphere of data was collected using 400e606 scans in
u
(0.3e0.5ꢁ per scan) at
f
¼ 0, 90 and 180ꢁ (for 3,
f
¼ 0, 120 and 240ꢁ)
using the SMART software package [46]. The raw data were reduced
to F2 values using the SAINTþ [47] software and global refinements
of unit cell parameters employing 3274e11,158 reflections chosen
from the full data set were performed. Multiple measurements of
equivalent reflections provided the basis for empirical absorption
correction as well as a correction for any crystal deterioration
during the data collection (SADABS) [48]. The structure of 7 was
solved by Patterson method, while the remaining structures were
solved by direct methods and all were refined by full-matrix least-
squares procedures using the SHELXTL program package [49].
Hydrogen atoms attached to carbon were placed in calculated
[34] M.S. Balakrishna, R. Venkateswaran, J.T. Mague, Inorg. Chem. 48 (2009)
1398e1406.
[35] P. Chandrasekaran, J.T. Mague, M.S. Balakrishna, Inorg. Chem. 44 (2005)
7925e7932.

3622
M.S. Balakrishna et al. / Journal of Organometallic Chemistry 696 (2011) 3616e3622
[36] M.S. Balakrishna, D. Suresh, A. Rai, J.T. Mague, D. Panda, Inorg. Chem. 49
(2010) 8790e8801.
[43] G. Giordano, R.H. Crabtree, Inorg. Synth. 28 (1990) 88e90.
[44] M.A. Bennett, T.N. Huang, T.W. Matheson, A.K. Smith, Inorg. Synth. 21 (1982)
74e78.
[45] M.C. Brandys, M.C. Jennings, R.J. Puddephatt, J. Chem. Soc. Dalton Trans.
(2000) 4601e4606.
[46] SMART, Version 5.625. Bruker-AXS, Madison, WI, 2000.
[47] SAINTþ, Version 6.35A. Bruker-AXS, Madison, WI, 2002.
[48] G.M. Sheldrick, SADABS, Version 2.05. University of Göttingen, Germany, 2002.
[49] SHELXTL, Version 6.10. Bruker-AXS, Madison, WI, 2000;
G.M. Sheldrick, SHELXS97andSHELXL97. UniversityofGöttingen, Germany,1997.
[37] S. Priya, M.S. Balakrishna, J.T. Mague, J. Organomet. Chem. 679 (2003) 116e124.
[38] E.Y.Y. Chan, Q.-F. Zhang, Y.-K. Sau, S.M.F. Lo, H.H.Y. Sung, I.D. Williams,
R.K. Haynes, W.-H. Leung, Inorg. Chem. 43 (2004) 4921e4926.
[39] K.R. Dixon, A.D. Rattray, Inorg. Chem. 16 (1977) 209e211.
[40] T. Ghaffer, A. Kieszkiewicz, S.C. Nyburg, A.W. Parkins, Acta Cryst C50 (1994)
697e700.
[41] D. Drew, J.R. Doyle, Inorg. Synth. 28 (1990) 346e349.
[42] J.A. McCleverty, G. Wilkinson, Inorg. Synth. 28 (1990) 84e86.