Synthesis and structural study of (8-phenylsulfanylnaphth-1-yl)diphenylphosphine metal complexes

Article abstract of DOI:10.1016/j.poly.2010.03.006

A series of three platinum(II) halide complexes 2-4 [Pt(X)₂{Nap(PPh₂)(SPh)}] (Nap = naphthalene-1,8-diyl; X = Cl, Br, I) and a ruthenium(II) p-cymene complex 5 [Ru(η⁶-MeC₆H₄ⁱPr)(Cl){Nap(PPh₂)(SPh)}]⁺Cl^- of the sterically crowded peri-substituted naphthalene phosphine 1 have been prepared. The compounds were fully characterised by multinuclear NMR, IR and MS and X-ray data for 1-5 are compared. Molecular structures are analysed by naphthalene ring torsions, peri-atom displacement, splay angle magnitude, P···S interactions, aromatic ring orientations and geometry around the metal centre. Platinum adopts a strictly square planar geometry which increases the distortion of the naphthalene skeleton in 2-4. Conversely, the classical-piano stool conformation of 5 results in a pseudo-octahedral conformation around the ruthenium atom which influences the naphthalene geometry to a much lesser extent with distortion of a similar magnitude to the free ligand 1.

Full text of DOI:10.1016/j.poly.2010.03.006

Polyhedron 29 (2010) 1956–1963
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Synthesis and structural study of (8-phenylsulfanylnaphth-1-yl)diphenylphosphine
metal complexes
*
Fergus R. Knight, Amy L. Fuller, Alexandra M.Z. Slawin, J. Derek Woollins
School of Chemistry, University of St Andrews, St Andrews, Fife KY16 9ST, UK
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of three platinum(II) halide complexes 2–4 [Pt(X)2{Nap(PPh2)(SPh)}] (Nap = naphthalene-1,8-
i
diyl; X = Cl, Br, I) and a ruthenium(II) p-cymene complex 5 [Ru(
g
6-MeC6H4 Pr)(Cl){Nap(PPh2)(SPh)}]+ClÀ
Received 20 February 2010
Accepted 10 March 2010
Available online 15 March 2010
of the sterically crowded peri-substituted naphthalene phosphine 1 have been prepared. The compounds
were fully characterised by multinuclear NMR, IR and MS and X-ray data for 1–5 are compared. Molecular
structures are analysed by naphthalene ring torsions, peri-atom displacement, splay angle magnitude,
PÁÁÁS interactions, aromatic ring orientations and geometry around the metal centre. Platinum adopts a
strictly square planar geometry which increases the distortion of the naphthalene skeleton in 2–4. Con-
versely, the classical-piano stool conformation of 5 results in a pseudo-octahedral conformation around
the ruthenium atom which influences the naphthalene geometry to a much lesser extent with distortion
of a similar magnitude to the free ligand 1.
Keywords:
Naphthalene
Peri-Substitution
Platinum
Ruthenium
Complex
Ó 2010 Elsevier Ltd. All rights reserved.
Phosphine
Sulfur
X-ray structure
1. Introduction
ences of the P and S donors of the chelate ligand might control
reaction selectivities via operation of the trans effect. In this con-
The theory of hemilability was introduced in the late 1970s [1]
and since then there has been great interest in mixed ligands con-
taining different donor atoms [2] and their uses associated with
coordination chemistry and homogenous catalysis. The difference
in electronic properties of the two donor atoms ensures they have
distinctive interactions with the metal centre. One site offers a
‘soft’ donor atom which binds strongly to a ‘soft’ transition metal
atom such as Rh(I), Pt(II) or Ru(II), whilst a ‘hard’ donor atom is less
strongly bound and is thus coordinatively labile. The significance of
hemilabile ligands in homogeneous catalysis lies in the susceptibil-
ity of the weak donor atom to dissociate from the metal, forming a
free coordination site for the incoming substrate, and the increased
stability of the catalyst precursor due to the chelating ability of
these bidentate ligands [3].
The ever-increasing demand for novel catalytic systems has fo-
cused attention on preparing low-valent transition-metal com-
plexes containing mixed bidentate ligands with a significant
contrast between the properties of coordinating groups [4].
Ligands possessing one strong and one weak donor atom such as
P,O- [5] and P,N-donor [6] ligands have been extensively applied
in catalysis and there is a growing interest with respect to potential
applications of P,S-ligands [7]. Additionally, the electronic differ-
text, (8-phenylsulfanylnaphth-1-yl)diphenylphosphine 1 [8,9] is a
suitable candidate because it is an asymmetric chelating ligand
with substantial electronic and steric differences between the
two donor atoms.
The work presented in this paper builds on our earlier studies of
sterically crowded 1,8-disubstituted naphthalenes [8–10] and
complements the work on copper(I) dimers previously undertaken
[9]. Herein we report on the synthesis and structural study of a
complete series of platinum(II) halide complexes of 1 (2–4) along
with a ruthenium(II) p-cymene complex 5 (Fig. 1).
2. Results and discussion
Ligand 1 reacts with the well known precursors [PtX2(cod)]
(cod = cyclooctadiene; X = Cl, Br, I) to afford a series of platinum(II)
dihalide complexes, 2, 3 and 4 (Scheme 1) [11,12]. Following the
displacement of the cyclooctadiene component, the square planar
platinum atom coordinates to two halogen atoms and to the biden-
tate ligand 1 via sulfur and phosphorus forming a six-membered
ring 2–4 [Pt(X)2{Nap(PPh2)(SPh)}] (Nap = naphthalene-1,8-diyl;
X = Cl, Br, I). All four complexes were characterised by multinuclear
NMR and IR spectroscopy, mass spectrometry and microanalysis.
31P NMR spectroscopy data is displayed in Table 1.
The phosphorus-31 NMR spectra for the platinum complexes
* Corresponding author.
E-mail address: jdw3@st-and.ac.uk (J.D. Woollins).
display an [AX]-pattern (A = PIII, X = Pt) with large values for
0277-5387/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2010.03.006

F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
1957
Table 1
Phosphorus-31 spectroscopic data for 1–5 [d (ppm), J (Hz)].
Compound
dP
1J{31P–195Pt}
1
2
3
4
5
À5.30
1.37
0.98
0.34
37.99
n/a
3521
3408
3263
n/a
Fig. 1. Platinum (II) 2–4 and ruthenium (II) 5 complexes of the peri-substituted
naphthalene phosphine 1.
1J{31P–195Pt}, indicative of direct coordination of one phosphorus
atom to the platinum centre. Signals for all three complexes occur
upfield compared with ligand 1 and a move to lower chemical
shifts is observed with the decreasing electronegativity of the hal-
ogen from chlorine to iodine. A decrease in the coupling constants
of the platinum satellites is also observed [2 Cl d = 1.37 ppm,
1J{31P–195Pt} = 3521 Hz, 3 Br d = 0.98 ppm, 1J{31P–195Pt} = 3408 Hz,
4 I d = 0.343 ppm, 1J{31P–195Pt} = 3263 Hz]. The values for the chlo-
ride coupling constant lie between the values for Pt(dppe)Cl2
(1J{31P–195Pt} = 3620 Hz) [13] and Pt(dppp)Cl2 (1J{31P–195Pt} =
3406 Hz) [14] and are in the range for similar sulfur/phosphorus
platinum dihalide complexes in the literature [15].
Scheme 2. The reaction scheme for the preparation of [Nap(PPh2)(SPh)Ru(Cl)(g6
MeC6H4iPr)]+ClÀ 5.
-
The decrease in the coupling constants from the dichloride
complex to the diiodide species is fully consistent with the larger
trans influence of iodine relative to chlorine [16–18]. The variation
in J(Pt–P) is not reflected in the P–Pt bond lengths of the three
complexes [2 Cl 2.232(3) Å, 3 Br 2.2326(15) Å, 4 I 2.319(2) Å].
crystallises with one molecule in the asymmetric unit. Selected
interatomic distances, angles and torsion angles are listed in Table
2. Further crystallographic information can be found in Table 4 and
the Supporting information.
The molecular structures of 2–4 are shown in Fig. 2. The three
monomeric chelated metal complexes have similar structures with
a typical square planar metal environment. In each case, the
unsymmetrical phosphino-sulfanyl ligand 1 acts as a bidentate li-
gand coordinating via the phosphorus(III) and the sulfur atom to
form a six-membered chelate ring. As a consequence of the geom-
etry of the ligand, the halogen atoms in the three complexes ar-
range in a cis-orientation. Square planar geometry around the
central metal is consistent throughout the series with angles
around the platinum atom varying only slightly from 90° (Table
2, Fig. 3).
The Pt–X(1) bond trans to P(1) is longer in all three species
compared to the Pt–X(2) bond trans to S(1), which is consistent
with the greater trans influence of phosphorus compared to sulfur
[18] As expected, Pt–X bonds lengthen with increasing size of the
halogen atom and non-bonded intramolecular halogen–halogen
distances increase to accommodate the larger atoms. The remain-
ing non-bonded intramolecular distances around the platinum
core also increase to maintain the square planar geometry
(Fig. 3). Pt–S and Pt–P bond distances are within the usual ranges
[15].
When ligand 1 was treated with an equimolar amount of
i
[Ru(g
6-MeC6H4 Pr)Cl2]2 dimer in dichloromethane at room temper-
i
ature, the complex [Ru(
g
6-MeC6H4 Pr)(Cl){Nap(PPh2)(SPh)}]+ClÀ
5
was obtained as an air-stable red solid (Scheme 2). The 31P NMR
spectrum displays a down field shift [37.99 ppm] compared with
1 with a chemical shift in accord with similar compounds from
the literature (Table 1) [19].
A loss of the twofold symmetry of the p-cymene ligand is ob-
served in the 1H NMR spectrum, similar to other reported p-cym-
ene complexes [20]. Coordination of ruthenium to four unrelated
ligands makes the central metal stereogenic. The methyl protons
of the isopropyl group and the aromatic protons of the p-cymene
ligand are diastereotopic and thus inequivalent in the 1H NMR
spectrum altering the pattern of resonances compared with the ini-
tial dimer [21]. The four aromatic hydrogen atoms of the p-cymene
ligand appear as four sets of doublets at ca d = 5.5–4.9 ppm instead
of two doublets as in the starting complex and the two isopropyl
methyls of the p-cymene appear as two doublets at d = 0.93 and
0.69 ppm instead of one doublet.
The PtSPC3 six-membered rings in 2–4 are hinged about the
PÁ Á ÁS vector and can be described as a twisted envelope type con-
formation; P(1), S(1), C(1), C(10) and C(9) are approximately copla-
nar with the platinum atom sitting in the peri-gap above this plane.
The displacement of Pt(1) from the C(1)–C(10)–C(9)–P(1)–S(1)
plane is comparable in all three compounds [2 1.05(1) Å, 3
1.00(1) Å, 4 1.00(1) Å] with the angle inclined by the Pt(1)–P(1)–
S(1) plane being similar [2 42.0(4)°, 3 39.4(4)°, 4 38.9(5)°].
The square planar conformation of ligand atoms around the
central platinum metal together with the increasing size of the hal-
ogen atoms dictates the geometry of the naphthalene scaffold and
the peri-substituents in 2–4. This is contrary to the effects of cop-
per coordination we observed in our previous paper [9]. As ex-
pected, the non-bonded intramolecular halogen–halogen distance
lengthens when larger halogen atoms are present. To maintain
the square planar geometry around platinum, the peri-atoms are
3. X-ray investigations
Single crystals were obtained for 2–5 by diffusion of pentane
into saturated solutions of the individual compound in dichloro-
methane. The molecular structures were analysed; each complex
Scheme 1. Reaction scheme for the preparation of the (8-phenylsulfanylnaphth-1-
yl)diphenylphosphine platinum (II) dihalides 2, 3, 4.

1958
F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
Table 2
Selected interatomic distances (Å) and angles (°) for 1–5.
Compound
1 [8,9]
2
3
4
5
Peri-region distances and sub-van der Waals contacts
P(1)Á Á ÁS(1)
3.0330(7)
0.567; 84
1.8548(19)
1.785(2)
3.182(6)
0.418; 88
1.80(2)
3.191(3)
0.409; 89
1.807(13)
1.763(13)
3.203(2)
0.397; 89
1.837(6)
1.770(7)
3.013(3)
0.587; 84
1.816(10)
1.829(10)
R
rvdW – PÁ Á ÁS; %
R
rvdWa
P(1)–C(1)
S(1)–C(9)
1.76(2)
Naphthalene bond lengths
C(1)–C(2)
C(2)–C(3)
C(3)–C(4)
C(4)–C(5)
C(5)–C(10)
C(5)–C(6)
C(6)–C(7)
C(7)–C(8)
C(8)–C(9)
1.376(3)
1.404(3)
1.353(3)
1.415(3)
1.442(3)
1.420(3)
1.358(3)
1.399(3)
1.377(3)
1.437(3)
1.448(3)
1.40(2)
1.40(3)
1.35(2)
1.44(2)
1.41(3)
1.44(3)
1.39(3)
1.38(3)
1.38(2)
1.46(2)
1.45(2)
1.366(17)
1.409(18)
1.339(17)
1.415(17)
1.428(18)
1.426(17)
1.350(18)
1.386(17)
1.377(16)
1.444(16)
1.465(16)
1.395(9)
1.398(10)
1.369(9)
1.411(10)
1.456(9)
1.404(9)
1.341(10)
1.401(12)
1.383(9)
1.434(9)
1.437(8)
1.385(14)
1.399(14)
1.381(15)
1.396(14)
1.444(14)
1.425(14)
1.348(15)
1.384(15)
1.394(13)
1.414(14)
1.434(13)
C(9)–C(10)
C(10)–C(1)
Peri-region bond angles
P(1)–C(1)–C(10)
C(1)–C(10)–C(9)
S(1)–C(9)–C(10)
124.07(13)
126.90(17)
123.11(13)
128.7(14)
125.0(18)
124.4(14)
126.9(8)
125.6(11)
125.8(8)
125.9(4)
127.8(6)
126.2(4)
124.9(7)
127.7(9)
121.3(7)
R
of bay angles
R
= 374.1(3)
R
= 378.1(32)
R
= 378.3(19)
R
= 379.9(10)
R = 373.9(16)
Splay angleb
14.1
18.1
18.3
19.9
13.9
C(4)–C(5)–C(6)
118.60(18)
117(2)
120.0(12)
119.7(6)
118.2(9)
Out-of-plane displacement
P(1)
S(1)
0.007(1)
0.127(1)
0.212(23)
À0.294(22)
0.303(135)
À0.299(13)
À0.003(8)
À0.074(9)
À0.096(10)
0.217(10)
Central naphthalene ring torsion angles
C:(6)–(5)–(10)–(1)
C:(4)–(5)–(10)–(9)
178.49(16)
À179.5(2)
175.9(16)
176.9(16)
170.8(10)
174.7(10)
À178.2(7)
À177.2(7)
176.9(7)
177.5(7)
Metal geometry – bond lengthsc
P(1)–M(1)
S(1)–M(1)
M(1)–L(1)
M(1)–L(2)
–
–
–
–
2.221(4)
2.261(4)
2.376(4)
2.300(5)
2.232(3)
2.256(3)
2.4817(14)
2.4244(15)
2.2326(15)
2.2752(16)
2.6553(4)
2.6052(4)
2.319(2)
2.356(2)
2.396(2)
1.744(1)d
Metal geometry – bond angles
P(1)–M(1)–S(1)
P(1)–M(1)–L(1)
P(1)–M(1)–L(2)
S(1)–M(1)–L(1)
–
–
–
–
–
–
90.46(17)
176.70(18)
92.55(17)
87.77(16)
175.35(18)
89.39(17)
90.61(11)
175.93(8)
92.92(8)
86.26(8)
175.58(8)
90.09(4)
90.56(5)
80.22(8)
89.03(9)
–
89.61(8)
–
–
176.21(4)
92.43(4)
87.42(4)
168.80(5)
90.163(15)
S(1)–M(1)–L(2)
L(1)–M(1)–L(2)
a
b
c
van der Waals radii used for calculations: rvdW(P) 1.80 Å, rvdW(S) 1.80 Å [22].
Splay angle:
R of the three bay region angles – 360.
L(1): X(1) for 2–4, Cl(1) for 5, L(2): X(2) for 2–4, pCy for 5.
M(1)–L(2): RuÁ Á Ácentroid distance.
d
Table 3
Torsion angles (°) categorising the naphthyl and phenyl ring conformations in 2, 3, 4 and 5.
Compound
C(10)–C(1)–P(1)–C(11)
C(10)–C(1)–P(1)–C(17)
C(10)–C(9)–S(1)–C(23)
Naphthalene ring conformations
2
3
4
5
h1 À146.2(1); twist
h1 142.2(1); twist
h1 155.0(1); equatorial
h1 À92.6(1); axial
h2 À103.8(1); axial
h2 À105.4(1); axial
h2 À94.6(1); axial
h3 69.7(1); axial
h3 72.4(1); axial
h3 86.6(1); axial
h3 164.6(1); equatorial
h2 155.4(1); equatorial
C(1)–P(1)–C(11)–C(12)
C(1)–P(1)–C(17)–C(18)
C(9)–S(1)–C(23)–C(24)
Phenyl ring conformations
2
3
4
5
c1 À72.5(1); axial
c1 À65.6(1); axial
c1 À70.3(1); axial
c1 À161.6(1); equatorial
c2 À0.30(1); equatorial
c2 177.4(1); equatorial
c2 À32.4(1); equatorial
c2 103.0(1); axial
c3 23.0; equatorial
c3 162.2(1); equatorial
c3 À8.4(1); equatorial
c3 À112.8(1); axial
forced further apart and non-covalent intramolecular PÁ Á ÁS separa-
tions are elongated [2 3.182(6) Å, 3 3.191(3) Å, 4 3.203(2) Å]. The
peri-distance in all three complexes is significantly longer than
phosphine 1 [3.0330(7) Å] and is an indication of the enhanced ste-
ric interactions and extra naphthalene distortion taking place com-
pared to the free ligand. Nonetheless, the peri-distance in all three
complexes is shorter than the sum of van der Waals radii for phos-
phorus and sulfur by 11–12%.

F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
1959
Table 4
Crystallographic data for compounds 2–5.
Compound
2. CH2Cl2
3. CH2Cl2
4. CH2Cl2
5. (CH3)2CO
Empirical formula
Formula weight
C29H22Cl5PPtS
805.88
C29H23Br2PPtSCl2
860.34
C29H23I2PPtSCl2
954.34
C41H41Cl2OPRuS
784.78
Temperature (°C)
Crystal colour, habit
Crystal dimensions (mm3)
Crystal system
À148(1)
À148(1)
À148(1)
À148(1)
Colourless, prism
0.10 Â 0.05 Â 0.03
Monoclinic
Colourless, platelet
0.12 Â 0.12 Â 0.03
Monoclinic
Yellow, prism
0.21 Â 0.21 Â 0.03
Monoclinic
Orange, block
0.21 Â 0.09 Â 0.03
Monoclinic
Lattice parameters
a (Å)
b (Å)
c (Å)
13.524(6)
15.311(7)
14.029(6)
–
12.8977(13)
15.5520(14)
14.5122(15)
–
15.053(4)
11.559(3)
17.567(4)
–
9.829(3)
22.199(6)
17.506(5)
–
b (°)
102.103(9)
–
2840(2)
P21/n
103.571(3)
–
2829.7(5)
P21/n
108.385(5)
–
2900.7(12)
P21/c
106.021(6)
–
3671.4(18)
P21/n
4
1.42
1616
7.045
16 039
0.083
Volume, V (Å3)
Space group
Z value
4
4
4
Dcalc (g/cm3)
F(0 0 0)
1.884
1560
55.392
22 810
0.087
2.019
1640
81.09
15 702
0.069
2.185
1784
72.769
18 781
0.042
m(Mo K
a
) (cmÀ1
)
Number of reflections measured
Rint
Minimum and maximum transmissions
Independent reflections
0.570–0.847
4928
0.493–0.784
5127
0.475–0.804
5877
0.861–0.979
6381
Observed reflection (number of variables)
Reflection/parameter ratio
4650(335)
14.71
4639(326)
15.73
5732(326)
18.03
5505(430)
14.84
Residuals: R1 (I > 2.00s(I))
0.0987
0.1044
0.2505
1.169
5.58
À2.23
0.0677
0.0774
0.1637
1.255
1.10
À1.61
0.0394
0.041
0.1146
1.223
2.32
À2.25
0.1126
0.1311
0.1848
1.3
0.93
À0.57
Residuals: R (all reflections)
Residuals: wR2 (all reflections)
Goodness of fit indicator
Maximum peak in final difference map (e/Å3)
Minimum peak in final difference map (e/Å3)
Fig. 2. Crystal structures of the platinum halide complexes 2, 3 and 4 illustrating the centroid–centroid distance resulting in
p–p stacking. The full numbering of the
naphthalene ligand is illustrated in Fig. 4.
Fig. 3. The angles (°) and distances (Å) associated with the square planar geometry of the platinum metal in the dihalide complexes 2, 3 and 4.
The increase in the PÁ Á ÁS separation is accompanied by a widen-
directions and there is a notable increase in the positive splay an-
gle [2 18.1°, 3 18.3°, 4 19.9°] compared with phosphine 1 [14.1°]. A
ing of the bay region; P–C and S–C bonds are tilted in opposite

1960
F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
similar displacement of the peri-atoms to either side of the naph-
thalene least-squares plane is observed in chloride 2 and bromide
3 [0.2–0.3 Å], but only a minor out-of-plane distortion is displayed
by iodide 4 whose peri-atoms essentially lie on the naphthyl plane
[0.003(8) Å, À0.074(9) Å].
The general distortion of the naphthalene skeleton is observed
in all three complexes with stretching of C–C bonds and C–C–C an-
gles. Bond lengths around C10, closer to the repulsive interactions,
are on average longer than those around C5 [average 1.45 Å and
1.42 Å respectively] and C(1)–C(10)–C(9) bond angles splay to a
mean 126°, away from the ‘ideal’ geometry as observed for C(4)–
C(5)–C(6) (average 119°) [23]. Further deformation of the naphtha-
lene geometry is observed with a buckling of the usually rigid
backbone. Maximum C–C–C–C torsion angles are in the range 2°–
4° for 2 and 4 but the deviation from planarity is more pronounced
in bromide 3 [ca 5°–9°].
Fig. 5. Core in the crystal structure of complex 5 illustrating the geometry around
the six-membered RuPSC3 ring.
The molecular structure of 5 is shown in Figs. 4 and 5. The metal
centre adopts a classical piano-stool geometry with coordination
by the aromatic p-cymene ligand, a terminal chlorine ligand and
the unsymmetrical phosphino-sulfanyl ligand 1. The chlorine atom
and the peri-atoms of 1 act as the legs of the piano stool and point
away from the p-cymene ligand to avoid steric overcrowding
resulting in a pseudo-octahedral ruthenium(II) metal centre.
Like the platinum halides 2–4, 1 acts as a bidentate ligand coor-
dinating via phosphorus(III) and sulfur forming a six-membered
chelate ring (Fig. 4). A twisted envelope type conformation of the
RuSPC3 six-membered ring is displayed with a hinge about the
PÁ Á ÁS vector; P(1), S(1), C(1), C(10) and C(9) are approximately
coplanar with the ruthenium atom sitting in the peri-gap but
1.39(1) Å above this plane and the Pt(1)–P(1)–S(1) plane is inclined
by 51.2(4)°.
Thegeometricalarrangementofthefreeligand, [Nap(PPh2)(SPh)]
1, in the platinum(II) halides 2–4 can be described by the conforma-
tion and arrangement of the naphthyl and phenyl rings, relative to
the C(ar)–P(1)–C(ar) and C(ar)–S(1)–C(R) planes. When h and
c
approach 90° the orientation is denoted axial and when the angles
indicate a quasi-planar arrangement (close to 180°), they are
termed equatorial (see Table 3) [24]. When angle h is axial, the
respective P–CPh/S–CPh bond lies perpendicular to the naphthyl
plane whilst an equatorial conformation aligns the bond on or
close to the plane. Axial conformations of angle h correspond to a
type A structureand equatorialto type B [24,25]. From previously re-
ported nomenclature [25], the structural arrangement ligand 1
adopts in complexes 2–4 can thus be described as type BA–A-c
(c-cis orientation of phenyl groups with respect to the naphthyl
plane) [25].
The ruthenium metal centre in 5 influences the molecular dis-
tortion of the naphthalene scaffold to a much lesser extent com-
pared with the rigid square planar geometry in the platinum
complexes. The degree of steric strain occurring in the naphthalene
moiety in 5 is comparable to that of the free ligand 1. The non-
bonded intramolecular peri-distance [3.013(3) Å] is notably shorter
than the separation found in the platinum complexes and similar
to that of the free ligand [3.0330(7) Å 1]. Corresponding splay an-
gles 14.1° 1 and 13.9° 5 are also noticeably more acute compared
with the platinum species [18.1–19.9°] implying P–C and S–C
bonds are tilted away from each other to a lesser extent due to
the reduced steric repulsion acting in the bay region. The displace-
ment of the phosphorus and sulfur atoms from the best naphtha-
lene plane in the ruthenium complex is minimal but slightly
more pronounced compared with the free ligand [0.007(1) Å and
0.127(1) Å 1; À0.10(1) Å and 0.22(1) Å 5]. No major distortion of
the naphthalene skeleton is observed in 5 with the maximum C–
C–C–C torsion angle 3.1° for C(6)–C(5)–C(10)–C(1).
Torsion angles (c) show that the two phenyl rings arranged cis
to the naphthyl plane adopt equatorial conformations in all three
complexes and thus overlap in a slipped packing arrangement; 2
[
c2 À0.30(1)°, c3 23.0(1)°], 3 [c2 177.4(1)°, c3 162.1(1)°], 4 [c2
À32.4(1)°, c3 À8.4(1)°] [26]. The distance between the two inter-
acting centroids increases with the increasing size of the halogen
atoms but in all cases this distance is within the known range for
typical centroid–centroid
stacking is envisaged [Cg(17–22)Á Á ÁCg(23–28): 2 3.536(1) Å,
3 3.574(1) Å, 4 3.598(1) Å].
p-stacking [3.3–3.8 Å] [26] so possible
p–p
Torsion angles h (Table 3) indicates the naphthalene unit in 5
displays an equatorial–axial–equatorial conformation with respect
to the C(ar)–P(1)–C(ar) and C(ar)–S(1)–C(R) planes. This arrange-
ment corresponds to a BA–B type arrangement [24,25]. Only one
phenyl ring lies perpendicular to the naphthalene plane so no over-
lap of axial centroids and therefore no
[26].
p–p stacking is observed
4. Conclusion
The design and synthesis of novel phosphorus ligands is of great
importance to chemists and is an area which has seen great devel-
opment. The work presented in this paper describes the metal
coordination of our previously reported ligand (8-phen-
ylsulfanylnaphth-1-yl)diphenylphosphine
ments the preliminary work undertaken by us on a series of
copper(I) dimers [9].
1 [8,9] and comple-
Fig. 4. The crystal structure of [Nap(PPh2)(SPh)Ru(Cl)(g
6-MeC6H4iPr)]+ClÀ 5,
(counteranion ClÀ omitted for clarity).

F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
1961
The unsymmetrical phosphino-sulfanyl ligand
1
has been
1964w, 1577s, 1478s, 1434s, 1321s, 1258w, 1154s, 1096vs,
1204s, 994s, 941s, 885s, 830vs, 765vs, 736vs, 687vs, 584vs,
526vs, 505vs, 418vs, 330vs, 294s; dH(270 MHz, CDCl3) 8.31–8.26
(1 H, m, nap 5-H), 8.26–8.21 (2 H, m, nap 4,7-H), 7.70–7.64 (1 H,
m, nap 6-H), 7.53–7.42 (3 H, m, nap 3-H, 2 Â PPh2 4-H), 7.42–
6.94 (12 H, m, nap 2-H, 2 Â PPh2 2,3,5,6-H), 6.85–6.76 (1 H, m,
SPh 4-H), 6.73–6.63 (4 H, m, SPh 2,3,5,6-H); dC(67.9 MHz, CDCl3)
139.3(d, J 4.2 Hz), 137.6(s), 135.2(s), 134.8(s), 133.7(s), 131.2(s),
128.8(d, J 6.2 Hz), 128.3(s), 128.1(d, J 5.1 Hz), 127.7(s), 126.6(s),
126.3(d, J 10.4 Hz); dP(109 MHZ, CDCl3) 1.37 (JP–Pt 3521.2 Hz); m/
shown to act as a bidentate ligand which can coordinate via both
phosphorus(III) and the sulfur atom to form six-membered chelate
rings [9]. Upon treatment with the known precursors [PtX2(cod)]
(X = Cl, Br, I), the naphthalene units of the complexes formed are
forced into greater distortion to maintain the strictly square planar
geometry required by the central platinum atom. Non-bonded
peri-distances are noticeably longer and increase with the increas-
ing size of the halogen atoms. Likewise there is an increase in the
positive splay angles in the bay region in the platinum species and
the peri-atoms are displaced to greater distances from the mean
naphthalene plane. This is contrary to the effects of the tetrahedral
environment of the copper atom when coordinated to 1 we ob-
served in our previous paper, which showed no influence on the
z (ES+) 651.10, ([MÀCl]+, 60%), 614.13 ([MÀCl2]+ 100%).
,
5.3. (8-Phenylsulfanylnaphth-1-yl)diphenylphosphine platinum
dibromide [Pt(Br)2{Nap(PPh2)(SPh)}] 3
naphthalene structure [9]. Coordination of 1 with the precursor
i
[Ru(g
6-MeC6H4 Pr)Cl2]2 dimer afforded
a
classical-piano stool
(0.2 g, 98%); (Found: C, 43.0; H, 2.6. Anal. Calc. for C28H21-
structure with a pseudo-octahedral coordination of the ruthenium
atom. The degree of steric strain operating in the naphthalene unit
was observed to be of a similar magnitude to that occurring in the
free ligand and the copper dimers previously reported, with corre-
sponding values for the displacement of peri-atoms within and out
of the plane and consequently the non-covalent peri-distance.
PSPtBr2: C, 43.5; H, 2.7%); vmax(KBr tablet)/cmÀ1: 3047s, 1578w,
1477s, 1434vs, 1339s, 1269s, 1181s, 1154s, 1095vs, 996s, 887s,
827s, 766vs, 735vs, 585s, 569s, 525vs, 503vs; dH(270 MHz, CDCl3)
8.30–8.26 (2 H, m, nap 5,7-H), 8.26–8.22 (1 H, m, nap 4-H), 7.69–
7.64 (1 H, m, nap 6-H), 7.53–7.46 (2 H, m, nap 2,3-H), 7.46–6.96
(10 H, m, 2 Â PPh2 2-6-H), 6.84–6.78 (1 H, m, SPh 4-H), 6.74–6.62
(4 H, m, SPh 2,3,5,6-H); dC(67.9 MHz, CDCl3) 139.6(d, J 4.2 Hz),
137.5(s), 135.2(s), 134.7(s), 133.8(br s), 131.1(s), 128.8(s),
5. Experimental
128.6(s), 128.2(br s), 127.7(s), 126.6(s), 126.2(d,
J 9.3 Hz);
dP(109 MHz, CDCl3) 0.98 (JP–Pt 3408.6 Hz); m/z (ES+) 695.05
All experiments were carried out under an oxygen- and mois-
ture-free nitrogen atmosphere using standard Schlenk techniques
and glassware. Reagents were obtained from commercial sources
and used as received. Dry solvents were collected from a MBraun
solvent system. (8-Phenylsulfanylnaphth-1-yl)diphenylphosphine
1 was prepared in house [8,9]. Elemental analyses were per-
formed by the University of St. Andrews School of Chemistry
Microanalysis Service. Infra-red spectra were recorded as KBr
discs in the range 4000–300 cmÀ1 on a Perkin–Elmer System
2000 Fourier transform spectrometer. 1H and 13C NMR spectra
were recorded on a Jeol GSX 270 MHz spectrometer with d(H)
and d(C) referenced to external tetramethylsilane. 31P NMR spec-
tra were recorded on a Jeol GSX 270 MHz spectrometer with d(P)
([MÀBr]+, 100%), 614.13 ([MÀBr2]+ 22%).
,
5.4. (8-Phenylsulfanylnaphth-1-yl)diphenylphosphine platinum
diiodide [Pt(I)2{Nap(PPh2)(SPh)}] 4
(0.1 g, 99%); (Found: C, 36.1; H, 2.2. Anal. Calc. for C28H21PSPtI2:
C, 36.5; H, 2.4%); vmax(KBr tablet)/cmÀ1: 3050w, 2962w, 2221w,
1573w, 1476s, 1434s, 1335w, 1260s, 1151w, 1095vs, 1021vs,
907s, 882s, 800vs, 764s, 727vs, 690vs, 581s, 564s, 522s, 502s,
476w, 450w; dH(270 MHz, CDCl3) 8.33–8.27 (2 H, m, nap 5,7-H),
8.27–8.20 (1 H, m, nap 4-H), 7.70–7.62 (1 H, m, nap 6-H), 7.57–
7.43 (2 H, m, nap 2,3-H), 7.43–6.95 (10 H, m, 2 Â PPh2 2-6-H),
6.83–6.75 (1 H, m, SPh 4-H), 6.75–6.68 (2 H, m, SPh 2,6-H), 6.68–
6.59 (2 H, m, SPh 3,5-H); dC(67.9 MHz, CDCl3) 139.7(d, J 3.4 Hz),
137.3(s), 134.9(s), 134.4(d, J 2.9 Hz), 130.9(s), 128.7(s), 128.3(s),
127.7(s), 126.5(s), 126.1(d, J 10.5 Hz); dP(109 MHz, CDCl3) 0.34
(JP–Pt 3263.1 Hz); m/z (ES+) 742.06 ([MÀI]+, 100%).
referenced to external phosphoric acid. Assignments of 13C and 1
H
NMR spectra were made with the help of H–H COSY and HSQC
experiments. All measurements were performed at 25 °C. All val-
ues reported for NMR spectroscopy are in parts per million (ppm).
Coupling constants (J) are given in Hertz (Hz). Mass spectrometry
was performed by the University of St. Andrews Mass Spectrom-
etry Service. Electron impact mass spectrometry (EIMS) and
Chemical Ionisation Mass Spectrometry (CIMS) was carried out
on a Micromass GCT orthogonal acceleration time of flight mass
spectrometer. Electrospray Mass Spectrometry (ESMS) was car-
ried out on a Micromass LCT orthogonal accelerator time of flight
mass spectrometer.
5.5. (8-Phenylsulfanylnaphth-1-yl)diphenylphosphine ruthenium
i
p-cymene chloride [Ru(
g
6-MeC6H4 Pr)(Cl) {Nap(PPh2)(SPh)}] 5
To a schlenk tube containing ligand (8-phenylsulfanylnaphth-1-
yl)diphenylphosphine (0.12 g, 0.29 mmol) and [Ru(pCy)Cl2]2
(0.18 g, 0.29 mmol) was added dichloromethane (5 mL). The reac-
tion was stirred for 2 h and the filtered. Removal of the solvent
and recrystallisation of the red solid from dichloromethane/pen-
tane gave orange crystals (0.1 g, 92%); vmax(KBr tablet)/cmÀ1
:
5.1. Platinum halide complexes of ligand 1 [Pt(X)2{Nap(PPh2)(SPh)}]
3397br, 3053vs, 2961vs, 2272w, 1656vs, 1467s, 1436vs, 1387vs,
1319s, 1278w, 1198w, 1157w, 1113s, 1093s, 1055s, 1030s, 997w,
875s, 821w, 758s, 693vs, 560s, 519s, 498s, 448vs, 294s;
dH(270 MHz, CDCl3) 8.03 (1 H, d, J 7.2 Hz, SPh 4-H), 7.99–7.87 (3
H, m, nap 4-H, SPh 2,6-H), 7.83 (1 H, d, J 8.0 Hz, nap 5-H), 7.65–
7.35 (12 H, m, SPh 3,5-H, 2 Â PPh2 2-6-H), 7.35–7.16 (3 H, m, nap
2,3,6-H), 7.03 (1 H, d, J 6.9 Hz, nap 7-H), 5.47 (1 H, d, J 6.4 Hz, Ar-
H), 5.40 (1 H, d, J 5.9 Hz, Ar-H), 5.27 (1 H, d, J 5.9 Hz, Ar–H), 4.98
(1 H, d, J 6.4 Hz, Ar–H), 2.30–2.10 (1 H, m, Ar–CH(CH3)2), 1.89 (3
H, s, Ar–CH3), 0.93 (3 H, d, J 6.9 Hz, Ar–CH(CH3)2), 0.69 (3 H, d, J
To a schlenk tube containing ligand 1 (8-phenylsulfanylnaphth-
1-yl)diphenylphosphine (1 molar equivalent) and Pt(cod)X2 (1 mo-
lar equivalent) was added dichloromethane (5 mL). The reaction
was stirred for 1 h and the solvent removed to near dryness. Suit-
able crystals were obtained by diffusion of pentane into saturated
solution of the individual compound in dichloromethane.
5.2. (8-Phenylsulfanylnaphth-1-yl)diphenylphosphine platinum
dichloride [Pt(Cl)2{Nap(PPh2)(SPh)}] 2
6.9 Hz, Ar–CH(CH3)2); dC(67.9 MHz, CDCl3) 134.6(d,
J 2.1 Hz),
(0.08 g, 98%); (Found: C, 48.6; H, 3.4. Calc. for C28H21PSPtCl2: C,
134.0(d, J 4.1 Hz), 133.9(d, J 3.1 Hz), 133.3(s), 132.5(s), 132.4(s),
131.8(d, J 2.0 Hz), 131.7(s), 131.5(s), 130.8(s), 129.8(d, J 10.4 Hz),
49.1; H, 3.1%); vmax(KBr tablet)/cmÀ1: 3430br, 3054s, 2919s,

1962
F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
V.C. Gibson, N.J. Long, A.J.P. White, C.K. Williams, D.J. Williams,
Organometallics 21 (2002) 770;
R. Romeo, L.M. Scolaro, M.R. Plutino, A. Romeo, F. Nicolo’, A. Del Zotto, Eur. J.
Inorg. Chem. (2002) 629;
129.4(d, J 10.4 Hz), 125.7(s), 125.5(d, J 9.4 Hz), 96.0(s), 95.9(s),
81.3(s), 80.6(s), 30.7(s), 22.8(s), 20.6(s), 18.4(s); dP (109 MHz,
CDCl3) 37.99; m/z (ES+) 691.12 ([M]+, 100%).
E. Cerrada, L.R. Falvello, M.B. Hursthouse, M. Laguna, A. Luquin, C. Pozo-
Gonzalo, Eur. J. Inorg. Chem. (2002) 826;
D. Morales-Morales, R. Redón, Y. Zheng, J.R. Dilworth, Inorg. Chim. Acta 328
(2002) 39;
6. Crystal structure analyses
O. Pamies, M. Dieguez, G. Net, A. Ruiz, C. Claver, Organometallics 19 (2000)
1488;
E. Hauptman, P.J. Fagan, W. Marshall, Organometallics 18 (1999) 2061;
A. Albinati, J. Herrmann, P.S. Pregosin, Inorg. Chim. Acta 264 (1997) 33;
A. Albinati, J. Eckert, P.S. Pregosin, H. Rüegger, R. Salzmann, C. Stössel,
Organometallics 16 (1997) 579;
J. Herrmann, P.S. Pregosin, R. Salzmann, Organometallics 14 (1995) 3311;
N. Brugat, A. Polo, A. Alvarez-Larena, J.F. Piniella, J. Real, Inorg. Chem. 38 (1999)
4829.
X-ray crystal structures were determined for compounds 2–5 at
À148(1) °C on a Rigaku ACTOR-SM, Saturn 724 CCD area detector
with SHINE optic using Mo K
a radiation (k = 0.71073 Å). The data
were corrected for Lorentz, polarisation and absorption. The data
for the complexes analysed was collected and processed using
CrystalClear (Rigaku) [27]. The structures were solved by direct
methods [28] and expanded using Fourier techniques [29]. The
non-hydrogen atoms were refined anisotropically. Hydrogen
atoms were refined using the riding model. All calculations were
performed using the CrystalStructure [30] and SHELXL 97 [31].
Although several attempts were made the crystal quality for 2
was poor; the high residual peak cited is very close to the platinum
centre.
[8] F.R. Knight, A.L. Fuller, M. Bühl, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J.,
accepted for publication.
[9] F.R. Knight, A.L. Fuller, A.M.Z. Slawin, J.D. Woollins, Dalton Trans. (2009) 8476.
[10] S.M. Aucott, H.L. Milton, S.D. Robertson, A.M.Z. Slawin, G.D. Walker, J.D.
Woollins, Chem. Eur. J. 10 (2004) 1666;
S.M. Aucott, H.L. Milton, S.D. Robertson, A.M.Z. Slawin, J.D. Woollins,
Heteroatom Chem. 15 (2004) 531;
S.M. Aucott, H.L. Milton, S.D. Robertson, A.M.Z. Slawin, J.D. Woollins, Dalton
Trans. (2004) 3347;
S.M. Aucott, P. Kilian, H.L. Milton, S.D. Robertson, A.M.Z. Slawin, J.D. Woollins,
Inorg. Chem. 44 (2005) 2710;
Acknowledgements
S.M. Aucott, P. Kilian, S.D. Robertson, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J.
12 (2006) 895;
S.M. Aucott, D. Duerden, Y. Li, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J. 12
(2006) 5495;
P. Kilian, D. Philp, A.M.Z. Slawin, J.D. Woollins, Eur J. Inorg. Chem (2003) 249;
P. Kilian, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J. 9 (2003) 215;
P. Kilian, A.M.Z. Slawin, J.D. Woollins, Chem. Commun. (2003) 1174;
P. Kilian, A.M.Z. Slawin, J.D. Woollins, Dalton Trans. (2003) 3876;
P. Kilian, H.L. Milton, A.M.Z. Slawin, J.D. Woollins, Inorg. Chem. 43 (2004)
2252;
Elemental analyses were performed by Sylvia Williamson and
Mass Spectrometry was performed by Caroline Horsburgh. The
work in this project was supported by the Engineering and Physical
Sciences Research Council (EPSRC).
Appendix A. Supplementary data
P. Kilian, A.M.Z. Slawin, J.D. Woollins, Inorg. Chim. Acta 358 (2005) 1719;
P. Kilian, A.M.Z. Slawin, J.D. Woollins, Dalton Trans. (2006) 2175;
F.R. Knight, A.L. Fuller, A.M.Z. Slawin, J.D. Woollins, Polyhedron, submitted for
publication;
F.R. Knight, A.L. Fuller, M. Bühl, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J.,
accepted for publication (chalcogen-chalc);
F.R. Knight, A.L. Fuller, M. Bühl, A.M.Z. Slawin, J.D. Woollins, Chem. Eur. J.,
accepted for publication (halo-chalcogen);
A.L. Fuller, F.R. Knight, A.M.Z. Slawin, J.D. Woollins, Eur. J. Inorg. Chem.,
submitted for publication.
CCDC 766927–66930 contains the supplementary crystallo-
graphic data for 2–5. 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.ca-
m.ac.uk. Supplementary data associated with this article can be
found, in the online version, at doi:10.1016/j.poly.2010.03.006.
[11] P. Kilian, A.M.Z. Slawin, J.D. Woollins, Dalton Trans. (2003) 3876.
[12] A. Karaçar, M. Freytag, H. Thönnessen, J. Omelanczuk, P.G. Jones, R. Bartsch, R.
Schmutzler, Z. Anorg. Allg. Chem. 626 (2000) 2361.
References
[13] Y. You, J. Chen, M. Cheng, Y. Wang, Inorg. Chem. 30 (1991) 3621.
[14] M.A. Bennett, A. Rockicki, Aust. J. Chem. 38 (1985) 1307.
[15] O.G. Mancheno, R.G. Arrayas, J.C. Carretero, Organometallics 24 (2005) 557;
V.C. Gibson, N.J. Long, A.J.P. White, C.K. Williams, D.J. Williams, M. Fontani, P.
Zanello, J. Chem. Soc., Dalton Trans. (2002) 3280;
[1] J.C. Jeffrey, T.B. Rauchfuss, Inorg. Chem. 18 (1979) 2658;
J.A. Davies, F.R. Hartley, Chem. Rev. 81 (1981) 79.
[2] A. Heûler, J. Fischer, S. Kucken, O. Stelzer, Chem. Ber. 127 (1994) 481;
E. Lindner, M. Haustein, H.A. Mayer, K. Gierling, R. Fawzi, M. Steimann,
Organometallics 14 (1995) 2246;
S.D. Toto, M.M. Olmstead, B.W. Arbuckle, P.K. Bharadwaj, K.W. Musker, Inorg.
Chem. 29 (1990) 691;
A. Karacar, M. Freytag, H. Thonnessen, J. Omelanczuk, P.G. Jones, R. Bartsch, R.
Schmutzler, Z. Anorg. Allg. Chem. 626 (2000) 2361;
R. Malacea, L. Routaboul, E. Manoury, J.-C. Daran, R. Poli, J. Organomet. Chem.
693 (2008) 1469.
T.B. Higgins, C.A. Mirkin, Inorg. Chim. Acta 240 (1995) 347;
M. Tepper, O. Stelzer, T. Haèusler, W.S. Sheldrick, Tetrahedron Lett. 38 (1997)
2257;
J. Heinicke, R. Kadyrov, M.K. Kindermann, M. Kloss, A. Fischer, P.G. Jones, Chem.
Ber. 129 (1996) 1061;
J. Heinicke, U. Jux, R. Kadyrov, M. He, Heteroat. Chem. 8 (1997) 383;
P. Wehman, H.M.A. van Donge, A. Hagos, P.C.J. Kamer, P.W.N.M. van Leeuwen,
J. Organomet. Chem. 535 (1997) 183;
A. Heûler, S. Kucken, O. Stelzer, W.S. Sheldrick, J. Organomet. Chem. 553 (1998)
39;
M. Hingst, M. Tepper, O. Stelzer, Eur. J. Inorg. Chem. (1998) 73;
D. Tanner, P. Wyatt, F. Johansson, S.K. Bertilsson, P.G. Andersson, Acta Chem.
Scand. 53 (1999) 263;
M. McCarthy, P.J. Guiry, Tetrahedron 55 (1999) 3061;
D.D. Ellis, G. Harrison, A.G. Orpen, H. Phetmung, P.G. Pringle, J.G. deVries, H.
Oeverding, J. Chem. Soc., Dalton Trans. (2000) 671;
J.J. Schneider, Nachr. Chem. 48 (2000) 614.
[16] B.J. Coe, S.J. Glenwright, Coord. Chem. Rev. 203 (2000) 5.
[17] K.M. Anderson, A.G. Orpen, Chem. Commun. (2001) 2682; A. Pidcock, R.E.
Richards, L.M. Venanzi, J. Chem. Soc. A (1966) 1707.
[18] T.G. Appleton, H.C. Clark, L.E. Manzer, Coord. Chem. Rev. 10 (1973) 335;
T.G. Appleton, J.R. Hall, S.F. Ralph, Inorg. Chem. 24 (1985) 4685;
M.H. Johansson, Å. Oskarsson, K. Lövqvist, F. Kiriakidou, P. Kapoor, Acta
Crystallogr., Sect. C 57 (2001) 1053 and references therein.
[19] M. Dochnahl, M. Doux, E. Faillard, L. Ricard, P. Le Floch, Eur. J. Inorg. Chem.
(2005) 125.
[20] C.G. Hamaker, D.P. Halbach, Inorg. Chim. Acta 359 (2006) 846;
I. Moldes, E. de la Encarnación, J. Ros, Á. Alvarez-Larena, J. F. Piniella, J.
Organomet. Chem. 566 (1998) 165.
[3] G.W. Parshall (Ed.), Homogeneous Catalysis, Wiley, New York, Chichester,
Brisbane, Toronto, 1962; C. Masters (Ed.), Homogeneous Transition Metal
Catalysis, Chapman and Hall, London, 1981.
ˇ
ˇ
[21] P. Govindaswamy, B. Therrien, G. Süss-Fink, P. Štepnicka,
Organomet. Chem. 692 (2007) 1661.
Ludvík, J.
A. Bondi, J. Phys. Chem. 68 (1964) 441.
[22]
[4] A.R. Sanger, Can. J. Chem. 61 (1983) 2214;
[23] C.A. Coulson, R. Daudel, J.M. Robertson, Proc. Roy. Soc. (London) A207 (1951)
306;
G. Anderson, R. Kumar, Inorg. Chem. 23 (1984) 4064;
F. Agbossou-Niedercorn, in: R. Comils, W.A. Herrmann (Eds.), Applied
Homogeneous Catalysis with Organometallic Compounds, vol. 2, VCH,
Weinheim, Germany, 2002, p. 1014.
D.W.J. Cruickshank, Acta Crystallogr. 10 (1957) 504;
C.P. Brock, J.D. Dunitz, Acta Crystallogr. B38 (1982) 2218;
J. Oddershede, S. Larsen, J. Phys. Chem. A 108 (2004) 1057.
[24] P. Nagy, D. Szabó, I. Kapovits, Á. Kucsman, G. Argay, A. Kálmán, J. Mol. Struct.
606 (2002) 61.
[5] S. Kudis, G. Helmcken, Angew. Chem., Int. Ed. 37 (1998) 3047.
[6] K. Yonehara, T. Hashizume, K. Mori, K. Ohe, S. Uemura, Chem. Commun. (1999)
415.
[7] H.-S. Lee, J.-Y. Bae, D.-H. Kim, H.S. Kim, S.-J. Kim, S. Cho, J. Ko, S.O. Kang,
Organometallics 21 (2002) 210;
[25] W. Nakanishi, S. Hayashi, J. Org. Chem. 67 (2002) 38;
S. Hayashi, K. Yamane, W. Nakanishi, J. Org. Chem. 72 (2007) 7587;

F.R. Knight et al. / Polyhedron 29 (2010) 1956–1963
1963
W. Nakanishi, S. Hayashi, S. Toyota, J. Am. Chem. Soc. 63 (1998) 8790;
W. Nakanishi, S. Hayashi, T. Uehara, J. Phys. Chem. 103 (1999) 9906;
W. Nakanishi, S. Hayashi, T. Uehara, Eur. J. Org. Chem. (2001) 3933.
[26] H.W. Roesky, M. Andruh, Coordin. Chem. Rev. 236 (2003) 91;
T. Koizumi, K. Tsutsui, K. Tanaka, Eur. J. Org. Chem. 9 (18) (2003) 4528;
C. Janiak, J. Chem. Soc., Dalton Trans. (2000) 3885.
[27] CrystalClear 1.6, Rigaku Corporation, CrystalClear Software User’s Guide,
Molecular Structure Corporation, Ó 2000; J.W.P. Flugrath, Acta Cryst. D55
(1999) 1718.
[28] SIR97, A. Altomare, M. Burla, M. Camalli, G. Cascarano, C. Giacovazzo, A.
Guagliardi, A. Moliterni, G. Polidori, R. Spagna, J. Appl. Cryst. 32 (1999) 115.
[29] DIRDIF99, P.T. Beurskens, G. Admiraal, G. Beurskens, W.P. Bosman, R. Israel,
J.M.M. Smits, The DIRDIF-99 Program System, Technical Report of the
Crystallography Laboratory, University of Nijmegen, The Netherlands, 1999.
[30] CrystalStructure 3.8.1, Crystal Structure Analysis Package, Rigaku and Rigaku/
MSC (2000–2006), 9009 New Trails Dr, The Woodlands, TX 77381, USA.
[31] SHELXL 97, G.M. Sheldrick, Acta Cryst. A 64 (2008) 112.