Synthesis and structural studies of RhI, PdI, NiII complexes and one-pot synthesis of binuclear RuII complex [(η6-p-cymene)Ru(μ2-Cl)3Ru{PhN(P(OC6H4OMe-o)<su

Article abstract of DOI:10.1016/j.jorganchem.2007.04.019

The Rh^I, Ru^II, Pd^I and Ni^II complexes of the aminobis(phosphonite), PhN(P(OC₆H₄OMe-o)₂)₂ (1) are reported. The reactions of 1 with [Rh(COD)Cl]₂ in 1:1 and 2

Full text of DOI:10.1016/j.jorganchem.2007.04.019

Journal of Organometallic Chemistry 692 (2007) 3400–3408
www.elsevier.com/locate/jorganchem
Synthesis and structural studies of RhI, PdI, NiII complexes
and one-pot synthesis of binuclear RuII complex
[(g6-p-cymene)Ru(l2-Cl)3Ru{PhN(P(OC6H4OMe-o)2)2}Cl]
a
b
a,
*
Chelladurai Ganesamoorthy , Joel T. Mague , Maravanji S. Balakrishna
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
Received 12 February 2007; received in revised form 4 April 2007; accepted 4 April 2007
Available online 21 April 2007
Abstract
The RhI, RuII, PdI and NiII complexes of the aminobis(phosphonite), PhN(P(OC6H4OMe-o)2)2 (1) are reported. The reactions of 1
with [Rh(COD)Cl]2 in 1:1 and 2:1 molar ratio afford the mono- and diolefin substituted chloro bridged chelate complexes,
[(COD)Rh2(l2-Cl)2{PhN(P(OC6H4OMe-o)2)2}] (2) and [Rh(l2-Cl){PhN(P(OC6H4OMe-o)2)2}]2 (3), respectively. Similarly, the cationic
mono- and bis-chelate complexes, [Rh(COD){PhN(P(OC6H4OMe-o)2)2}]OTf (4) and [Rh{PhN(P(OC6H4OMe-o)2)2}2]OTf (5) are
obtained by treating 1 with [Rh(COD)Cl]2 in the presence of AgOTf in appropriate ratios. The dinuclear RhI carbonyl complex,
[RhCl(CO){l-PhN(P(OC6H4OMe-o)2)2}]2 (6) is prepared by treating 1 with 0.5 equiv. of [Rh(CO)2Cl]2. Reaction of 1 with cis-
[NiBr2(DME)] (DME = 1,2-dimethoxyethane) affords [{PhN(P(OC6H4OMe-o)2)2}NiBr2] (7) whereas with [Ru-(g6-p-cymene)Cl2]2 in
refluxing THF medium produces an interesting and rare bimetallic RuII complex, [(g6-p-cymene)Ru(l2-Cl)3Ru{PhN(P(OC6H4OMe-
o)2)2}Cl] (8). Redox condensation of the Pd0 and PdII derivatives with 1 affords the dinuclear PdI complex, [PdBr{l-PhN(P(O-
C6H4OMe-o)2)2}]2 (9). The formation and structure of complexes 2–9 are assigned through various spectroscopic and micro analysis
data. The molecular structures of 5 and 7–9 are confirmed by single crystal X-ray diffraction studies.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Aminobis(phosphonite); Transition metal chemistry; Crystal structures; Chelate and bridged bidentate complexes
1. Introduction
pared to dppm and sterically less rigid in comparison with
P–O–P systems [3]. Further, the binding properties of these
ligands can be readily altered by changing the substituents
on both the phosphorus and the nitrogen centers. As a
result, the ligands with P–N–P framework have been suc-
cessfully employed in various catalytical reactions such as
Pauson-Khand reactions [4], copolymerization of CO and
ethylene [5], ethylene tri- [6] and tetramerization reactions
[7] and allylic substitution reactions [8]. In view of this,
recently we have synthesized and reported transition metal
chemistry and catalytic applications of several aminophos-
phines and aminobis(phosphines). As a part of our interest
in designing new ligands and studying their coordination
behavior [9] and catalytic applications [10], we report herein
the synthesis and structural characterization of RhI, RuII,
The transition metal chemistry of ‘‘short-bite’’ amin-
obis(phosphines) of the type X2PN(R)PX2 and their
bis(chalcogenide) derivatives has attracted considerable
attention in recent years because of the versatile coordina-
tion behavior of the former as it is similar to dppm [1] and
the potential application of latter as single source precursors
of various metal-, non-metal- and metalloid-telluride thin
films and nanoparticles [2]. However, the ligands with P–
N–P framework are found to be thermally more stable com-
*
Corresponding author. Tel.: +91 22 2576 7181; fax: +91 22 2576 7152/
2572 3480.
E-mail address: krishna@chem.iitb.ac.in (M.S. Balakrishna).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.04.019

C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
3401
PdI and NiII metal complexes of aminobis(phosphonite),
PhN(P(OC6H4OMe-o)2)2 (1).
The reaction between 1 and [Rh(CO)2Cl]2 in CH2Cl2
at room temperature affords dinuclear complex [RhCl-
(CO){l-PhN(P(OC6H4OMe-o)2)2}]2 (6) as an yellow-orange
color crystalline solid in good yield. In contrast, the same
reaction when carried out in refluxing CH3CN results in
the formation of chloro-bridged dimeric complex 3 in quan-
titative yield. The phosphorus-31 NMR spectrum of com-
plex 6 consists of an XAA0X0 multiplet centered at
2. Results and discussion
2.1. RhI derivatives
The reactions of PhN(P(OC6H4OMe-o)2)2 (1) with
[Rh(COD)Cl]2 in 1:1 and 2:1 molar ratio in CH2Cl2 lead
to the successive replacement of the diene ligands and
the formation of chloro bridged bimetallic chelate com-
plexes, [Rh2(l2-Cl)2(COD){PhN(P(OC6H4OMe-o)2)2}] (2)
and [Rh(l2-Cl){PhN(P(OC6H4OMe-o)2)2}]2 (3), respec-
tively. Similarly, the reactions of 1 with [Rh(COD)Cl]2 in
the presence of 2 equiv. of AgOTf in 2:1 and 4:1 molar
ratio afford the cationic chelate complexes, [Rh(COD)-
{PhN(P(OC6H4OMe-o)2)2}]OTf (4) and [Rh{PhN{P(OC6-
H4OMe-o)2}2}2]OTf (5), respectively, as shown in Scheme
1 [11].
117.1 ppm with j JRhP + 3JRhPj = 261 Hz and JPP = 130
Hz. Such type of spin multiplicity was observed in analogous
complexes containing bridging bis(phosphines) ligands
[9c,9d,9h,12]. The IR spectrum of 6 shows two mCO absorp-
tions at 2085 and 2021 cmꢀ1 which is consistent with the cis-
related CO/phosphine structures proposed for similar com-
plexes [13]. The microanalysis and 1H NMR spectral data are
consistent with the proposed structure of 6.
1
2
2.2. NiII, RuII and PdI Derivatives
The 31P NMR spectra of complexes 2–5 show doublets
The diamagnetic nickel(II) chelate complex, [{PhN(P(O-
C6H4OMe-o)2)2}NiBr2] (7) was prepared in high yield by
reacting 1 with cis-[NiBr2(DME)] (DME = 1,2-dimeth-
oxyethane) in THF at room temperature (Scheme 2). An
equimolar reaction between 1 and [Ru-(g6-p-cymene)Cl2]2
in THF at 60 ꢁC resulted in the formation of a rare tri-
chloro-bridged bimetallic complex, [(g6-p-cymene)Ru(l2-
Cl)3Ru{PhN(P(OC6H4OMe-o)2)2}Cl] (8) in which one of
the ruthenium(II) centers retains the cymene group irre-
spective of the stoichiometry of the ligand and the
reaction conditions. This represents the first one-pot syn-
thesis of a ruthenium(II) binuclear complex containing a
bisphosphine ligand. The other known complexes of this
type [(g6-p-cymene)Ru(l2-Cl)3Ru{L2}Cl] (L2 = (PPh3)2,
1
centered at 92.0, 89.7, 87.1 and 98.8 ppm with JRhP cou-
plings of 283, 282, 233 and 197 Hz, respectively, which
indicate the chemically and magnetically equivalent nature
1
of the phosphorus centers. The H NMR spectra of com-
plexes 2–5 show single resonances around the region of
3.4–3.8 ppm corresponding to the ortho-methoxy groups
present in the phenyl rings. The resonance due to olefinic
protons of COD in complexes 2 and 4 appear as broad
singlets at 3.91 and 5.39 ppm. The methylenic protons pres-
ent in complexes 2 and 4 exhibit two doublets at 2.29, 1.60
and 2.20, 1.61 ppm, respectively. The structure of the com-
plex 5 was confirmed by the single crystal X-ray diffraction
study.
+
R2
P
R2
P
Ph
iii
N
Rh
5
N
Ph
OTf
_
+
P
P
R2
P
R2
R2
_
Ph
N
Ph
N
Rh
4
OTf
iv
P
R2
R2 P
P
R2
Ph
Cl
CO
v
N
1
Rh
CO
R2 P
Rh
P
PR2
R2
Cl
ii
R = -OC6H4OMe-o
R
P
2
R2
P
R2
P
N
Cl
i
Ph
6
Rh
Ph
N
Rh
N Ph
R2
P
Cl
3
P
R2
P
Cl
R2
Ph N
Rh
Rh
P
R2
Cl
2
Scheme 1. (i) [Rh(COD)Cl]2, CH2Cl2. (ii) 1/2 [Rh(COD)Cl]2, CH2Cl2 or 1/2 [Rh(CO)2Cl]2, CH3CN, D with (iii) 1/2 [Rh(COD)Cl]2, AgOTf, CH2Cl2/
acetone. (iv) 1/4 [Rh(COD)Cl]2, 1/2 AgOTf, CH2Cl2/acetone with (v) 1/2 [Rh(CO)2Cl]2, CH2Cl2.

3402
C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
Ph
N
in Figs. 1–4, respectively. The selected bond lengths and
bond angles of compounds 5 and 7–9 are given in Tables 1
and 2, while crystal data and the details of the structure
determinations are given in Table 3. The X-ray crystal struc-
tural determination of complex 5 shows that it exists as a cat-
ionic bis-chelate complex. The rhodium occupies the center
of the distorted square planar geometry and the corners are
occupied by four phosphorus centers of the diphosphazane
ligands. Due to the formation of strained four-membered
chelate ring the P–N–P angle of the free ligand shrinks from
116.07(12)ꢁ to 99ꢁ (P1–N1–P2 = 99.1(3)ꢁ and P3–N2–P4 =
98.7(3)ꢁ). The bite angles created by the chelating ligands
Ph
N
R2
P
R
2 P
P
R2
Br
Br
iii
i
Br Pd
Pd Br
P
PR2
R2
Ph
N
Ni
1
P
R2
P
P
R2
R2
R = -OC6H4OMe-o
ii
N
7
Ph
9
R
P2
Cl
Cl
Ph
N
Ru
Cl
Ru
Cl
8
P
R2
Scheme 2. (i) NiBr2(DME), THF. (ii) [RuCl2(p-Cym)]2, THF, 60 ꢁC with
(iii) 1/4 Pd2(dba)3 Æ CHCl3, 1/2 PdBr2(CH3CN)2, CH2Cl2.
Ph2P(CH2)4PPh2, Cy2P(CH2)4PCy2) were prepared by mix-
ing symmetrically substituted binuclear complexes [L2-
ClRu(l-Cl)2(l-X)RuClL2] with [Ru-(g6-p-cymene)Cl2]2
through con-proportionation reactions as shown in
Scheme 3. The 31P NMR spectra of complexes 7 and 8
show single resonances at 68.1 and 100.1 ppm, respectively
and the 1H NMR spectra show singlets at 3.59 and
3.66 ppm corresponding to the ortho-methoxy protons.
The aromatic protons of p-cymene in complex 8 appear
as two doublets at 5.34 and 5.18 ppm with JHH coupling
of 5.2 Hz. The methyl groups of isopropyl moiety appear
as a doublet centered at 1.24 ppm with a JHH coupling of
6.8 Hz, whereas the –CH proton appears as a septet at
2.84 ppm. The binuclear PdI complex [PdIBr{l-PhN(P(O-
C6H4OMe-o)2)2}]2 (9) was prepared by a redox condensa-
tion process using a 1:2:4 mixture of Pd02(dba)3 Æ CHCl3,
PdIIBr2(CH3CN)2 and 1 in refluxing CH2Cl2. The 31P
NMR spectrum of 9 shows a single peak at 111.3 ppm
Fig. 1. Molecular structure of 5. All hydrogen atoms have been omitted
for clarity. Displacement ellipsoids are drawn at the 50% probability level.
1
and the H NMR data are consistent with the proposed
structure. The structures of complexes 7–9 were confirmed
by single crystal X-ray diffraction studies.
2.3. The crystal and molecular structures of 5 and 7–9
Perspective views of the molecular structures of com-
pounds 5 and 7–9 with atom numbering schemes are shown
Ph3P
Ph3P
R
Cl
Cl
Cl
Cl
Cl
Cl
[(arene)RuCl2]2
-L
Ru
Ru
2
Ru
Ru
PPh3
PPh3
PPh3
PPh3
L
Cl
Cl
(L = Me2CO,PhNHCHO)
Ph2
P
Cl
PhCN
PhCN
R
[(arene)RuCl2]2
- 4 PhCN
Cl
Cl
Cl
Ru
Cl
Ph2
P
Ru
2
Ru
P
Cl
P
Ph2
Ph2
Cy2
P
Cl
Cl
Cl
P
P
R
Cl
Cl
Cl
Cy2
P
Cy2
Cl
Ru
Ru
[(arene)RuCl2]2
- H2O
Cy2
Ru
2
Ru
OH2
P
Cl
P
Cy2
Fig. 2. Molecular structure of 7. All hydrogen atoms and lattice solvent
have been omitted for clarity. Displacement ellipsoids are drawn at the
50% probability level.
Cy2
Scheme 3.

C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
3403
P1–Rh–P2 and P3–Rh–P4 with Rh center are 69.98(6)ꢁ and
69.52(7)ꢁ, respectively, which are ꢁ4.5ꢁ larger than that
observed in molybdenum tetra carbonyl derivative (P1–
Mo–P2 = 65.02(4)ꢁ) [14]. The P1–Rh–P3 and P2–Rh–P4
bond angles (179.22(6)ꢁ and 173.01(7)ꢁ) are slightly deviated
from the linear geometry. The Rh–P distances ranges from
bered NP2Ni chelate ring is nearly planar. The Ni–P bonds
˚
are almost equidistant (Ni–P1 = 2.101(1) A and Ni–P2 =
˚
2.088(1) A) and are slightly shorter than those in the related
˚
˚
cis-[NiBr2{allyl-N(PPh2)2}] (2.112(1) A and 2.122(2) A), cis-
˚
[NiCl2{p-C6H4OMe-N(PPh2)2}] (2.115(2) A and 2.123(2)
˚
˚
A) [15], [1,3-{cis-NiBr2(PPh2)2N}2C6H4] (2.116(4) A) [5a],
cis-[NiBr2{Ph2PN(Ph)P(NtBu)2SiMe2}] (2.127(1) A and
˚
˚
˚
2.241(2) A (for Rh–P4) to 2.249(2) A (for Rh–P1).
˚
Crystals of 7 suitable for X-ray diffraction analysis were
grown by keeping the saturated THF solution of 7 at room
temperature for several days. The diamagnetism of the com-
pound had indicated the distorted square planar coordina-
tion geometry about the nickel center and is surrounded by
two cis-bromides and phosphorus atoms. The four-mem-
2.115(1) A) [16] and cis-[NiBr2{Ar2PN(Me)PAr2}], (Ar =
BuC6H4-o) (2.161(1) A) [5b] complexes. Due to the forma-
t
˚
tion of strained four-membered NP2Ni ring, the P–N–P
angle of free ligand is reduced from 116.07(12)ꢁ to 95.73
(13)ꢁ. The P1–Ni–P2 and Br1–Ni–Br2 angles are 73.24(4)ꢁ
and 100.70(2)ꢁ, respectively.
Complex 8 is a bimetallic RuII complex with Ru2 center
having g6-coordinated cymene ligand and Ru1 center is sur-
rounded by chlorides and a chelating diphosphazane ligand.
Fig. 3. Molecular structure of 8. All hydrogen atoms and lattice solvent
have been omitted for clarity. Displacement ellipsoids are drawn at the
50% probability level.
Fig. 4. Molecular structure of 9. All hydrogen atoms have been omitted
for clarity. Displacement ellipsoids are drawn at the 50% probability level.
Table 1
Selected bond distances and bond angles for complexes 5 and 7
Complex 5
Complex 7
˚
˚
Bond distances (A)
Bond angles (ꢁ)
Bond distances (A)
Bond angles (ꢁ)
P1–N1
P2–N1
P3–N2
P4–N2
Rh–P1
Rh–P2
Rh–P3
Rh–P4
P1–O1
P1–O3
P2–O5
P2–O7
1.692(6)
P1–N1–P2
P3–N2–P4
P1–Rh–P2
P3–Rh–P4
P1–Rh–P4
P2–Rh–P3
P1–Rh–P3
P2–Rh–P4
Rh–P1–N1
Rh–P2–N1
Rh–P3–N2
Rh–P4–N2
99.1(3)
98.7(3)
P1–N
P2–N
1.689(3)
P1–N–P2
95.73(13)
73.24(4)
100.70(2)
166.68(4)
93.70(3)
92.44(3)
165.50(4)
95.01(9)
95.70(9)
1.696(5)
1.698(7)
1.680(7)
2.249(2)
2.246(2)
2.253(2)
2.241(2)
1.576(5)
1.602(5)
1.585(5)
1.599(5)
1.681(3)
2.101(1)
2.088(1)
2.317(1)
2.327(1)
1.591(3)
1.577(3)
1.577(3)
1.588(3)
P1–Ni–P2
Br1–Ni–Br2
Br1–Ni–P1
Br1–Ni–P2
Br2–Ni–P1
Br2–Ni–P2
Ni–P1–N
69.98(6)
69.52(7)
109.81(7)
110.74(7)
179.22(6)
173.01(7)
95.47(19)
95.5(2)
P1–Ni
P2–Ni
Br1–Ni
Br2–Ni
P1–O1
P1–O3
P2–O5
P2–O7
Ni–P2–N
95.4(2)
96.4(2)

3404
C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
Table 2
Selected bond distances and bond angles for complexes 8 and 9
Complex 8
Complex 9
Bond distances (A)
˚
˚
Bond distances (A)
Bond angles (ꢁ)
Bond angles (ꢁ)
P1–N1
P2–N1
1.689(3)
1.699(3)
3.260(1)
2.375(1)
2.532(1)
2.500(1)
2.398(1)
2.174(1)
2.178(1)
2.444(1)
2.440(1)
2.412(1)
2.193(4)
2.182(4)
2.142(4)
2.170(4)
2.136(4)
2.166(4)
P1–N1–P2
P1–Ru1–P2
94.89(16)
69.97(4)
91.61(3)
91.48(3)
168.53(3)
93.13(4)
89.39(4)
79.72(3)
78.51(3)
81.84(3)
82.56(3)
85.36(2)
81.11(3)
106.00(3)
175.90(3)
172.54(3)
104.23(3)
95.19(3)
100.88(3)
P1–N1
P2–N1
P3–N2
P4–N2
P1–Pd1
P2–Pd2
P4–Pd1
P3–Pd2
Pd1–Br1
Pd2–Br2
Pd1–Pd2
1.685(3)
P1–N1–P2
P3–N2–P4
111.81(14)
114.02(14)
96.42(3)
92.96(3)
89.11(3)
95.21(3)
173.78(1)
170.21(1)
88.36(2)
87.69(2)
83.65(3)
88.62(2)
167.06(3)
174.39(3)
1.691(3)
1.677(3)
1.682(3)
2.240(2)
2.256(3)
2.257(2)
2.249(3)
2.480(1)
2.481(1)
2.618(1)
Ru1–Ru2
Ru1–Cl1
Ru1–Cl2
Ru1–Cl3
Ru1–Cl4
Ru1–P1
Ru1–P2
Ru2–Cl2
Ru2–Cl3
Ru2–Cl4
Ru2–C36
Ru2–C37
Ru2–C38
Ru2–C39
Ru2–C40
Ru2–C41
Cl1–Ru1–Cl2
Cl1–Ru1–Cl3
Cl1–Ru1–Cl4
Cl1–Ru1–P1
Cl1–Ru1–P2
Cl2–Ru1–Cl3
Cl2–Ru1–Cl4
Ru1–Cl2–Ru2
Ru1–Cl3–Ru2
Ru1–Cl4–Ru2
Cl3–Ru1–Cl4
Cl2–Ru1–P1
Cl2–Ru1–P2
Cl3–Ru1–P1
Cl3–Ru1–P2
Cl4–Ru1–P1
Cl4–Ru1–P2
Br1–Pd1–P1
Br1–Pd1–P4
Br2–Pd2–P2
Br2–Pd2–P3
Pd1–Pd2–Br2
Pd2–Pd1–Br1
Pd1–Pd2–P2
Pd1–Pd2–P3
Pd2–Pd1–P1
Pd2–Pd1–P4
P1–Pd1–P4
P2–Pd2–P3
Table 3
Crystallographic information for compounds 5, 7–9
5
7
8
9
Formula
Fw
C
69H65F3N2O19P4RhS
C36H33Br2NNiO8P2
888.06
C48.75H51Cl4N1.25O8.75P2Ru2
C68.5H68Br2N2O16.5P4Pd2
1679.77
Triclinic
1542.09
Orthorhombic
Pna21 (No. 33)
13.929(2)
39.565(7)
12.385(2)
90
1200.29
Monoclinic
C2/c (No. 15)
34.040(2)
19.1510(10)
18.5610(10)
90
96.4370(10)
90
12023.6(11)
8
1.326
0.779
4866
0.15 · 0.16 · 0.23
100
Crystal system
Space group
Monoclinic
P21/c (No. 14)
11.835(2)
11.467(2)
27.074(4)
90
101.3060(10)
90
3603.0(10)
4
1.637
2.898
1792
0.18 · 0.20 · 0.20
100
ꢀ
P1 (No. 2)
˚
a (A)
13.5040(10)
14.0960(10)
19.865(2)
84.118(2)
82.292(2)
63.3880(10)
3346.4(5)
2
1.667
1.898
1694
0.11 · 0.12 · 0.16
100
˚
b (A)
˚
c (A)
a ꢁ
b ꢁ
c ꢁ
90
90
3
˚
V (A )
6825.4(19)
4
1.501
0.458
3172
Z
qcalc (g cmꢀ3
)
l (Mo Ka) (mmꢀ1
F(000)
)
Crystal size (mm3)
T (K)
0.05 · 0.16 · 0.20
293
2h Range ꢁ
1.5–28.3
58,948
16,198 (0.058)
1.21
0.0803
0.1655
2.1–26.4
17,216
17,236 (0.000)
1.01
0.0582
0.1621
2.1–28.3
105,063
14,962 (0.060)
1.11
0.0508
0.1437
2.1–28.3
59,811
16,477 (0.052)
1.01
0.0406
0.0934
Total no. reflections
No. of independent reflections (Rint
)
GOF (F2)
R1a
wRb2
P
P
a
R = iFoj ꢀ jFci/ jFoj.
P
P
2
1=2
2
b
Rw ¼ f½ wðF 2o ꢀ F c2Þ= wðF 2oÞ ꢃg w ¼ 1=½r2ðF o2Þ þ ðxPÞ ꢃ where P ¼ ðF o2 þ 2F 2c Þ=3:
The tetrahedral {(g6-cymene)Ru2} fragment is connected
through three chloro bridges to the octahedral
{Ru1Cl(PNP)} moiety. The two phosphorus centers
(P1 and P2) are in cis positions and trans to chlorides (Cl3
and Cl2) with remaining chlorides (Cl1 and Cl4) are coordi-
nated trans to each other. As expected, the Ru–Cl bonds of
(Ru1–Cl1 = 2.375(1) A). The Ruꢂ ꢂ ꢂRu distance (Ru1–
˚
˚
˚
Ru2 = 3.260(1) A) is well outside the range (2.28–2.95 A)
usually observed for a Ru–Ru bond and is some what
shorter than that observed in analogous complexes [(1,3,5-
C6H3Et3)Ru(l2-Cl)3Ru(dppb)Cl] (3.326(1) A), [(g -C6H6)-
Ru(l2-Cl)3Ru(dppb)Cl] (3.314(1) A) (dppb = 1,4-bis(diphe-
6
˚
˚
˚
the bridging chlorides are longer (Ru1–Cl4 = 2.398(1) A–
nylphosphanyl)butane)
Cl)3Ru(PPh3)2Cl] (3.360(2) A) [17]. As observed for the
and
˚
[(1,3,5-C6H3iPr3)Ru(l2-
˚
Ru1–Cl2 = 2.532(1) A) than the terminal Ru–Cl bond

C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
3405
above complexes, the plane defined by g6-cymene ligand is
almost parallel to that defined by the bridging chloro
ligands. The non-bonded Pꢂ ꢂ ꢂP separations in complex 7
(dba)3 Æ CHCl3 [25] and NiBr2(DME) [26] were prepared
according to the published procedures. AgOTf was pur-
chased from Aldrich chemicals and used as such without
further purification. The 1H and 31P{1H} NMR (d in
ppm) spectra were recorded using Varian VXR 300 or
VXR 400 spectrometer operating at the appropriate fre-
quencies using TMS and 85% H3PO4 as internal and exter-
nal references, respectively. The spectra were recorded in
CDCl3 solutions with CDCl3 as an internal lock; positive
shifts lie downfield of the standard in all of the cases. Infra-
red spectra were recorded on a Nicolet Impact 400 FTIR
instrument as KBr disks. The microanalyses were per-
formed using Carlo Erba Model 1112 elemental analyzer.
The melting points were observed in capillary tubes and
are uncorrected.
˚
˚
and 8 are 2.499(1) A and 2.495(1) A, respectively, which
are shorter than that observed in complex
5
˚
˚
(P1ꢂ ꢂ ꢂP2 = 2.578 A and P3ꢂ ꢂ ꢂP4 = 2.562 A).
In complex 9, both the PdI centers are having distorted
square planar geometry and are surrounded by one Pd, two
P and one Br ligands. The Pd–Pd bond length in 9
˚
(2.6182(5) A) is almost identical to the same in the analo-
˚
gous complex [Pd{l-PhN(P(OPh)2)2}Cl]2 (2.619(1) A) [18]
˚
and ꢁ0.08 A shorter than that in [Pd(l-dppm)Br]2
˚
(2.699(5) A) [19]. The Pd–P bond distances in 9 ranges
˚
˚
from 2.239(1) A to 2.257(1) A, which are shorter than those
observed for [Pd(l-dppm)Br]2 complex. The P–N bond
˚
˚
lengths varies from 1.677(3) A to 1.691(3) A, which are sta-
tistically equivalent to the average distances found in
[Pd(l-dppa)Cl]2 [20] and [Pd{l-PhN(P(OPh)2)2}Cl]2 [18].
The four cis angles (Br–Pd–P) centered at the Pd1 and
Pd2 centers with bromine atoms are 96.42(3)ꢁ, 92.96(3)ꢁ,
89.11(3)ꢁ and 95.21(3)ꢁ, respectively. There is a pro-
nounced twist about the Pd–Pd bond with dihedral angles
of P1–Pd1–Pd2–P2 and P4–Pd1–Pd2–P3 are ꢀ41.31(3)ꢁ
and ꢀ34.90(3)ꢁ, respectively, which are typical for the
4.1. Synthesis of [(COD)Rh(l-Cl)2Rh{PhN(P(OC6H4-
OMe-o)2)2}] (2)
A solution of 1 (0.026 g, 0.040 mmol) in CH2Cl2 (5 mL)
was added dropwise to a solution of [RhCl(COD)]2
(0.020 g, 0.040 mmol) also in CH2Cl2 (5 mL) with constant
stirring. The reaction mixture was allowed to stir at room
temperature for 4 h. The resulting solution was concen-
trated to 2 mL, layered with 1 mL of petroleum ether,
and stored at ꢀ30 ꢁC for 1 day to give analytically pure
2+
M2(l-LL)2 skeleton. For example, the dihedral angle
between the square planes in [Pd(l-dppm)Br]2 is 39ꢁ.
Because of the bridging nature of the ligand, the complex
9 shows much longer Pꢂ ꢂ ꢂP separation when compare to
the chelate complexes.
1
product of 2. Yield: 79% (0.033 g), m.p.: 144–146 ꢁC. H
NMR (400 MHz, CDCl3): d 7.80–6.76 (m, 21H, ArH),
3.91 (br s, 4H, CH), 3.52 (s, 12H, OCH3), 2.29 and
1.60 ppm (d, 8H, CH2). 31P{1H}NMR (162 MHz, CDCl3):
1
3. Conclusion
d
92.0 ppm (d, JRh,P = 283 Hz). Anal. Calcd for
C42H45NO8P2Rh2Cl2(1030.47): C, 48.95; H, 4.40; N, 1.36.
Found: C, 48.90; H, 4.42; N, 1.34%.
The ‘short bite’ bidentate ligand 1 readily reacts with
various low valent transition metals to give either mono-
nuclear chelates or binuclear complexes depending upon
the reaction conditions and stoichiometry. With RhI
derivatives, various neutral and cationic complexes were
prepared. Reaction of 1 with NiII derivative yielded
four-membered chelate complex and with RuII derivative
half sandwich homo bimetallic complex 8 was formed.
This is the first report on one-pot synthesis of a binuclear
complex of the type 8 in excellent yield; the other two
known complexes were prepared involving two step con-
proportionation reactions. The redox reaction between
Pd0 and PdII in the presence of ligand 1 resulted in a
PdI dimer. The work on catalytic aspects of these com-
plexes is in progress.
4.2. Synthesis of [Rh(l-Cl){PhN(P(OC6H4OMe-o)2)2}]2
(3)
(a) A solution of [RhCl(COD)]2 (0.035 g, 0.071 mmol) in
CH2Cl2 (5 mL) was added dropwise to a solution of 1
(0.092 g, 0.142 mmol) also in CH2Cl2 (5 mL) with
constant stirring. The reaction mixture was allowed
to stir at room temperature for 4 h. The resulting
solution was concentrated to 4 mL, layered with
2 mL of petroleum ether, and stored at ꢀ30 ꢁC for
1 day to give orange precipitate of 3. Yield: 89%
(0.099 g).
(b) A mixture of [Rh(CO)2Cl]2 (0.027 g, 0.070 mmol) and
1 (0.091 g, 0.141 mmol) in acetonitrile (15 mL) was
stirred under reflux condition for 4 h. The solvent
was removed under reduced pressure, the residue
was redissolved in 3 mL of CH2Cl2 and diluted with
1 mL of petroleum ether. Keeping this solution at
ꢀ30 ꢁC for 1 day afforded orange colored crystalline
solid 3. Yield: 80% (0.088 g), m.p.: 168–170 ꢁC (dec).
1H NMR (400 MHz, CDCl3): d 7.72–6.64 (m, 42 H,
ArH), 3.46 ppm (s, 24H, OCH3). 31P{1H}NMR
4. Experimental
All experimental manipulations were performed under
rigorously anaerobic conditions using Schlenk techniques.
All the solvents were purified by conventional procedures
and distilled prior to use [21]. The aminobis(phosphonite),
PhN{P(OC6H4OMe-o)2}2 (1) was prepared as previously
reported [14]. The metal precursors [Rh(COD)Cl]2 [22],
[Rh(CO)2Cl]2 [23], [Ru(g6-cymene)Cl2]2 [24], Pd2-
1
(121 MHz, CDCl3): d 89.7 ppm (d, JRh,P = 282 Hz).

3406
C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
Anal. Calcd for C68H66N2O16P4Rh2Cl2 (1567.87): C,
52.09; H, 4.24; N, 1.79. Found: C, 52.02; H, 4.22; N,
1.84%.
stirring. After 1 h, the resulting red solution was kept at
room temperature for 2 days to give analytically pure red
crystals of 7. Yield: 92% (0.104 g), m.p.: 198–200 ꢁC
(dec). 1H NMR (400 MHz, CDCl3): d 7.66–6.64 (m,
21 H, ArH), 3.59 ppm (s, 12H, OCH3). 31P{1H} NMR
(162 MHz, CDCl3): d 68.1 ppm (s). Anal. Calcd for
C34H33NO8P2NiBr2(864.08): C, 47.26; H, 3.85; N, 1.62.
Found: C, 47.20; H, 3.88; N, 1.63%.
4.3. Synthesis of [Rh(COD){PhN(P(OC6H4OMe-o)2)2}]-
OTf (4)
AgOTf (0.021 g, 0.081 mmol) was added to the stirred
solution of [Rh(COD)Cl]2 (0.020 g, 0.041 mmol) in 5 mL
of acetone. After 30 min, a solution of 1 (0.052 g,
0.081 mmol) in 6 mL of CH2Cl2 was added dropwise and
stirred for 4 h. The suspension obtained was filtered to
remove AgCl, and the yellowish-orange filtrate was con-
centrated to 5 mL. Cooling this solution to ꢀ30 ꢁC, gave
1 as an analytically pure yellow crystalline solid. Yield:
66% (0.054 g), m.p.: 155–157 ꢁC (dec). 1H NMR
(400 MHz, CDCl3): d 7.67–6.90 (m, 21H, ArH), 5.39 (br
s, 4H, CH), 3.81 (s, 12H, OMe), 2.20 and 1.61 ppm (d,
8H, CH2). 31P{1H} NMR (162 MHz, CDCl3): d 87.1 ppm
(d, 1JRh,P = 233 Hz). Anal. Calcd for C43H45F3NO11P2SRh
(1005.73): C, 51.35; H, 4.51; N, 1.39; S, 3.19. Found: C,
51.41; H, 4.49; N, 1.33; S, 3.14%.
4.7. Synthesis of [(g6-cymene)Ru(l-Cl)3-
Ru(Cl){PhN(P(OC6H4OMe-o)2)2}] (8)
A mixture of [Ru(g6-cymene)Cl2]2 (0.041 g, 0.067 mmol)
and 1 (0.043 g, 0.067 mmol) in THF (15 mL) was stirred
under reflux condition for 5 h. It was cooled to room tem-
perature and concentrated to 5 mL under vacuum. Keeping
this solution at ꢀ30 ꢁC for several days afforded red crys-
1
tals of 8. Yield: 80% (0.060 g), m.p.: 210–212 ꢁC (dec). H
NMR (400 MHz, CDCl3): d 8.26–6.70 (m, 21H, ArH),
5.34 (d, JH,H = 5.2 Hz, 2H, cymene Ph), 5.18 (d, 2H,
cymene Ph), 3.66 (s, 12H, OCH3), 2.84 (sep, 1H, CH),
2.17 (s, 3H, CH3), 1.24 ppm (d, JH,H = 6.8 Hz, 6H,
C(CH3)2). 31P{1H} NMR (162 MHz, CDCl3):
d
100.1 ppm (s). Anal. Calcd for C44H47NO8P2Ru2Cl4-
(1123.74): C, 47.03; H, 4.22; N, 1.25. Found: C, 47.01; H,
4.26; N, 1.21%.
4.4. Synthesis of [Rh{PhN(P(OC6H4OMe-o)2)2}2]OTf
(5)
This was synthesized by a procedure similar to that of 4
using AgOTf (0.026 g, 0.101 mmol), [Rh(COD)Cl]2
(0.025 g, 0.051 mmol) and 1 (0.131 g, 0.203 mmol). Crystals
suitable for X-ray diffraction analysis were grown from 2:1
mixture of tetrahydrofuran/pet ether at ꢀ30 ꢁC. Yield: 91%
(0.142 g), m.p.: 190–192 ꢁC (dec). 1H NMR (400 MHz,
CDCl3): d 7.26–6.61 (m, 42 H, ArH), 3.45 ppm (s, 24H,
OCH3). 31P{1H} NMR (121 MHz, CDCl3): d 98.8 ppm
4.8. Synthesis of [PdBr{l-PhN(P(OC6H4OMe-o)2)2}]2
(9)
A mixture of Pd2(dba)3 Æ CHCl3 (0.031 g, 0.030 mmol),
Pd(CH3CN)2Br2 (0.021 g, 0.060 mmol) and 1 (0.077 g,
0.120 mmol) in CH2Cl2 (20 mL) was stirred under reflux
condition for 1 h. The resulting red-orange solution was
cooled and filtered. The filtrate was concentrated to 5 mL
and methanol (10 mL) was added to precipitate the prod-
uct. Recrystallization from CH2Cl2/MeOH mixture fol-
lowed by vacuum drying afforded analytically pure
product of 9. Yield: 45% (0.045 g), m.p.: 160–162 ꢁC
1
(d, JRh,P = 197 Hz). Anal. Calcd for C69H66F3N2-
O19P4SRh (1543.13): C, 53.70; H, 4.31; N, 1.82; S, 2.08.
Found: C, 53.63; H, 4.34; N, 1.86; S, 2.05%.
1
4.5. Synthesis of [Rh(CO)Cl{PhN(P(OC6H4OMe-
o)2)2}]2 (6)
(dec). H NMR (400 MHz, CDCl3): d 7.79–6.62 (m, 42H,
ArH), 3.59 ppm (s, 24H, OCH3). 31P{1H} NMR
(162 MHz, CDCl3): d 111.3 ppm (s). Anal. Calcd for
C68H66N2O16P4Pd2Br2 (1663.80): C, 49.09; H, 4.00; N,
1.68. Found: C, 49.11; H, 4.05; N, 1.66%.
This was synthesized by a procedure similar to that of 2
using [Rh(CO)2Cl]2 (0.020 g, 0.051 mmol) and 1 (0.066 g,
1
0.103 mmol). Yield: 76% (0.063 g); m.p.: 118–120 ꢁC. H
NMR (400 MHz, CDCl3): d 7.75–6.73 (m, 42H, ArH),
4.9. X-ray crystallography
3.78 ppm (s, 24H, OCH3). 31P{1H} NMR (162 MHz,
1
CDCl3):
d
117.1 ppm (m, j JRh,P + 3JRh,Pj = 262 Hz,
Crystals of 5 and 7–9 were mounted in a Cryoloopꢂ
with a drop of Paratone oil and placed in the cold nitrogen
stream of the Kryoflexꢂ attachment of the Bruker APEX
CCD diffractometer. A full sphere of data was collected
using 606 scans in x (0.3ꢁ per scan) at / = 0ꢁ, 120ꢁ and
240ꢁ or 400 scans in x (0.5ꢁ per scan) at / = 0ꢁ, 90ꢁ
and 180ꢁ plus 800 scans in / (0.45ꢁ per scan) at x = 0
and 210ꢁ using the SMART software package [27]. The raw
data were reduced to F2 values using the SAINT+ software
[28] and global refinements of unit cell parameters using
2JP,P = 130 Hz); FT-IR (KBr disc) cmꢀ1: m(CO) 2085,
2021. Anal. Calcd for C70H66N2O18P4Rh2Cl2(1623.89): C,
51.77; H, 4.10; N, 1.72. Found: C, 51.70; H, 4.14; N, 1.78%.
4.6. Synthesis of [NiBr2{PhN(P(OC6H4OMe-o)2)2}] (7)
A solution of 1 (0.085 g, 0.132 mmol) in THF (6 mL)
was added dropwise to a solution of NiBr2(DME)
(0.041 g, 0.132 mmol) also in THF (5 mL) with constant

C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
3407
(c) M. Afzaal, D. Crouch, M.A. Malik, M. Motevalli, P. O’Brien, J.-
H. Park, J.D. Woollins, Eur. J. Inorg. Chem. 1 (2004) 171;
(d) J. Waters, D. Crouch, J. Raftery, P. O’Brien, Chem. Mater. 16
(2004) 3289;
(e) D.J. Crouch, P. O’Brien, M.A. Malik, P.J. Skabara, S.P. Wright,
Chem. Commun. (2003) 1454;
6800–9550 reflections chosen from the full data sets were
performed. Multiple measurements of equivalent reflec-
tions provided the basis for empirical absorption correc-
tions as well as corrections for any crystal deterioration
during the data collection (SADABS [29]). All the structures
were solved by direct methods and refined by full-matrix
least-squares procedures using the SHELXTL program pack-
age [30]. Hydrogen atoms were placed in calculated posi-
tions and included as riding contributions with isotropic
displacement parameters tied to those of the attached
non-hydrogen atoms. Pertinent crystallographic data and
other experimental details are summarized in Table 3.
(f) J.-H. Park, M. Afzaal, M. Helliwell, M.A. Malik, P. O’Brien, J.
Raftery, Chem. Mater. 15 (2003) 4205.
[3] (a) C.M. Alvarez, B. Galan, M.E. Garcia, V. Riera, M.A. Ruiz, C.
Bois, Organometallics 22 (2003) 3039;
(b) J. Perez, D. Morales, V. Riera, A. Rodriguez, S. Garcia-Granda,
Dalton Trans. (2003) 1641;
(c) M.A. Alvarez, C. Alvarez, M.E. Garcia, V. Riera, M.A. Ruiz, C.
Bois, Organometallics 16 (1997) 2581;
(d) X. Liu, V. Riera, M.A. Ruiz, M. Lanfranchi, A. Tiripicchio, M.
Tiripicchio-Camellini, Organometallics 13 (1994) 1940;
(e) R.J. Haines, A. Pidcock, M. Safari, J. Chem. Soc., Dalton Trans.
(1977) 830;
Acknowledgements
(f) A.L. Du Preez, I.L. Marais, R.J. Haines, A. Pidcock, M. Safari, J.
Organomet. Chem. 141 (1977) C10.
[4] Y. Gimbert, F. Robert, A. Durif, M.-T. Averbuch, N. Kann, A.E.
Greene, J. Org. Chem. 64 (1999) 3492.
[5] (a) F. Majoumo-Mbe, P. Loennecke, E.V. Novikova, G.P. Belov, E.
Hey-Hawkins, Dalton Trans. (2005) 3326;
(b) N.A. Cooley, S.M. Green, D.F. Wass, K. Heslop, A.G. Orpen,
P.G. Pringle, Organometallics 20 (2001) 4769.
[6] (a) T. Agapie, M.W. Day, L.M. Henling, J.A. Labinger, J.E. Bercaw,
Organometallics 25 (2006) 2733;
We are grateful to the Department of Science and
Technology (DST), New Delhi, for funding through Grant
SR/S1/IC-05/2003. C.G. thanks CSIR for Junior Research
Fellowship (JRF). We also thank SAIF, Mumbai, Depart-
ment of Chemistry Instrumentation Facilities, Bombay, for
spectral and analytical data and the Louisiana Board
of Regents through grant LEQSF(2002-03)-ENH-TR-67
for purchase of the CCD diffractometer and the Tulane
University for support of the X-ray laboratory.
(b) L.E. Bowen, D.F. Wass, Organometallics 25 (2006) 555;
(c) S.J. Schofer, M.W. Day, L.M. Henling, J.A. Labinger, J.E.
Bercaw, Organometallics 25 (2006) 2743;
(d) K. Blann, A. Bollmann, J.T. Dixon, F.M. Hess, E. Killian, H.
Maumela, D.H. Morgan, A. Neveling, S. Otto, M.J. Overett, Chem.
Commun. (2005) 620;
(e) T. Agapie, S.J. Schofer, J.A. Labinger, J.E. Bercaw, J. Am.
Chem. Soc. 126 (2004) 1304;
(f) A. Carter, S.A. Cohen, N.A. Cooley, A. Murphy, J. Scutt, D.F.
Wass, Chem. Commun. (2002) 858.
Appendix A. Supplementary material
CCDC 631331, 631332, 631333 and 631334 contain the
supplementary crystallographic data for 5, 7, 8and 9. These
data can be obtained free of charge via http://www.ccdc.
cam.ac.uk/conts/retrieving.html, or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge
CB2 1EZ, UK; fax: (+44) 1223-336-033; or e-mail:
deposit@ccdc.cam.ac.uk. Supplementary data associated
with this article can be found, in the online version, at doi:
10.1016/j.jorganchem.2007.04.019.
[7] (a) A. Jabri, P. Crewdson, S. Gambarotta, I. Korobkov, R.
Duchateau, Organometallics 25 (2006) 715;
(b) M.J. Overett, K. Blann, A. Bollmann, J.T. Dixon, F. Hess, E.
Killian, H. Maumela, D.H. Morgan, A. Neveling, S. Otto, Chem.
Commun. (2005) 622;
(c) M.J. Overett, K. Blann, A. Bollmann, J.T. Dixon, D. Haasbroek,
E. Killian, H. Maumela, D.S. McGuinness, D.H. Morgan, J. Am.
Chem. Soc. 127 (2005) 10723;
References
(d) A. Bollmann, K. Blann, J.T. Dixon, F.M. Hess, E. Killian, H.
Maumela, D.S. McGuinness, D.H. Morgan, A. Neveling, S. Otto,
M. Overett, A.M.Z. Slawin, P. Wasserscheid, S. Kuhlmann, J. Am.
Chem. Soc. 126 (2004) 14712.
[1] (a) S.K. Mandal, T.S. Venkatakrishnan, A. Sarkar, S.S. Krishna-
murthy, J. Organomet. Chem. 691 (2006) 2969;
(b) M.S. Balakrishna, K. Ramaswamy, R.M. Abhyankar, J. Orga-
nomet. Chem. 560 (1998) 131;
`
[8] G. Calabro, D. Drommi, G. Bruno, F. Faraone, Dalton Trans.
(2004) 81.
(c) T.S. Venkatakrishnan, S.S. Krishnamurthy, M. Nethaji, J.
Organomet. Chem. 690 (2005) 4001;
(d) A.S. Veige, T.G. Gray, D.G. Nocera, Inorg. Chem. 44 (2005) 17;
(e) T.G. Gray, A.S. Veige, D.G. Nocera, J. Am. Chem. Soc. 126
(2004) 9760;
[9] (a) C. Ganesamoorthy, M.S. Balakrishna, P.P. George, J.T. Mague,
Inorg. Chem. 46 (2007) 848;
(b) P. Chandrasekaran, J.T. Mague, M.S. Balakrishna, Inorg. Chem.
45 (2006) 5893;
(c) P. Chandrasekaran, J.T. Mague, M.S. Balakrishna, Inorg. Chem.
45 (2006) 6678;
(f) M.S. Balakrishna, R. Panda, D.C. Smith, A. Klaman, S.P. Nolan,
J. Organomet. Chem. 599 (2000) 159;
(d) P. Chandrasekaran, J.T. Mague, M.S. Balakrishna, Organomet-
allics 24 (2005) 3780;
(e) P. Chandrasekaran, J.T. Mague, M.S. Balakrishna, Inorg. Chem.
44 (2005) 7925;
(f) M.S. Balakrishna, P.P. George, S.M. Mobin, Polyhedron 24
(2005) 475;
(g) S. Priya, M.S. Balakrishna, J.T. Mague, S.M. Mobin, Inorg.
Chem. 42 (2003) 1272;
(g) A.F. Heyduk, D.G. Nocera, J. Am. Chem. Soc. 122 (2000) 9415;
(h) T.Q. Ly, J.D. Woollins, Coord. Chem. Rev. 176 (1998)
451;
(i) P. Bhattacharyya, J.D. Woollins, Polyhedron 14 (1995) 3367;
(j) M.S. Balakrishna, S.V. Reddy, S.S. Krishnamurthy, J.F. Nixon,
J.C.T.R.B. St. Laurent, Coord. Chem. Rev. 129 (1994) l.
[2] (a) S.S. Garje, D.J. Eisler, J.S. Ritch, M. Afzaal, P. O’Brien, T.
Chivers, J. Am. Chem. Soc. 128 (2006) 3120;
(h) M.S. Balakrishna, R. Panda, J.T. Mague, J. Chem. Soc., Dalton
Trans. (2002) 4617;
(b) M. Afzaal, D.J. Crouch, P. O’Brien, J. Raftery, P.J. Skabara,
A.J.P. White, D.J. Williams, J. Mater. Chem. (2004) 233;

3408
C. Ganesamoorthy et al. / Journal of Organometallic Chemistry 692 (2007) 3400–3408
(i) M.S. Balakrishna, R. Panda, J.T. Mague, Inorg. Chem. 40 (2001)
5620.
[10] (a) B. Punji, J.T. Mague, M.S. Balakrishna, Dalton Trans. (2006)
(b) M.P. de Araujo, E.M.A. Valle, J. Ellena, E.E. Castellano, E.N.
dos Santos, A.A. Batista, Polyhedron 23 (2004) 3163;
(c) A.C. da Silva, H. Piotrowski, P. Mayer, K. Polborn, K. Severin,
Eur. J. Inorg. Chem. (2001) 685.
1322;
(b) B. Punji, C. Ganesamoorthy, M.S. Balakrishna, J. Mol. Catal. A:
Chem. 259 (2006) 78;
(c) B. Punji, J.T. Mague, M.S. Balakrishna, J. Organomet. Chem.
691 (2006) 4265;
[18] M.S. Balakrishna, S.S. Krishnamurthy, R. Murugavel, M. Nethaji,
I.I. Mathews, J. Chem. Soc., Dalton Trans. (1993) 477.
[19] R.G. Holloway, B.R. Penfold, R. Colton, M.J. McCormick, J.
Chem. Soc., Chem. Commun. (1976) 485.
(d) B. Punji, J.T. Mague, M.S. Balakrishna, Inorg. Chem. 45 (2006)
9454.
[20] C.S. Browning, D.H. Farrar, D.C. Frankel, J.J. Vittal, Inorg. Chem.
Acta 254 (1997) 329.
[11] (a) M.S. Balakrishna, S.S. Krishnamurthy, Inorg. Chim. Acta 230
(1995) 245;
(b) J. Ellermann, G. Szucsanyi, Z. Anorg. Allg. Chem. 520 (1985)
113.
[12] M. Cano, J.V. Heras, M.A. Lobo, E. Pinilla, M.A. Monge,
Polyhedron 13 (1994) 1563.
[21] W.L.F. Armarego, D.D. Perrin, Purification of Laboratory Chemi-
cals, 4th ed., Butterworth-Heinemann, Linacre House, Jordan Hill,
Oxford, UK, 1996.
[22] G. Giordano, R.H. Crabtree, Inorg. Synth. 28 (1990) 88.
[23] J.A. McCleverty, G. Wilkinson, Inorg. Synth. 28 (1990)
84.
[13] M.S. Balakrishna, B.D. Santarsiero, R.G. Cavell, Inorg. Chem. 33
(1994) 3079.
[24] M.A. Bennett, T.N. Huang, T.W. Matheson, A.K. Smith, Inorg.
Synth. 21 (1982) 74.
[14] M.S. Balakrishna, P.P. George, J.T. Mague, J. Organomet. Chem.
689 (2004) 3388.
[25] T. Ukai, H. Kawazura, Y. Ishii, J.J. Bonnet, J.A. Ibers, J. Organo-
met. Chem. 65 (1974) 253.
[15] (a) V.V. Sushev, A.N. Kornev, Y.A. Kurskii, O.V. Kuznetsova,
G.K. Fukin, Y.H. Budnikova, G.A. Abakumov, J. Organomet.
Chem. 690 (2005) 1814;
[26] L.G.L. Ward, Inorg. Synth. 13 (1971) 54.
[27] Bruker-AXS, SMART, Version 5.625, Madison, WI, 2000.
[28] Bruker-AXS, SAINT+, Version 6.35A, Madison, WI, 2002.
[29] G.M. Sheldrick, SADABS, Version 2.05, University of Go¨ttingen,
Germany, 2002.
(b) Z. Sun, F. Zhu, Q. Wu, S. Lin, Appl. Organomet. Chem. 20
(2006) 175.
[16] L.E. Anagho, J.F. Bickley, A. Steiner, L. Stahl, Angew. Chem., Int.
Ed. 44 (2005) 3271.
[30] (a) Bruker-AXS,
2000;
SHELXTL,
Version 6.10, Madison, WI,
[17] (a) S. Gauthier, L. Quebatte, R. Scopelliti, K. Severin, Chem. Eur. J.
10 (2004) 2811;
(b) G.M. Sheldrick, SHELXS97 and SHELXL97, University of Go¨ttingen,
Germany, 1997.