Reactivity of Ph2(2-C5H4N)PSe towards Ru3(CO)12 and mononuclear MCl2(PhCN) 2 (M=Pd or Pt) complexes

Article abstract of DOI:10.1016/S0020-1693(02)01518-9

The behavior of the Ph₂(2-C₅H₄N)PSe ligand in the reactions with Ru₃(CO)₁₂ and the mononuclear complexes MCl₂(PhCN)₂ (M=Pd or Pt) has been investigated. The reaction with Ru₃(CO)₁₂ is characterized by P=Se bond cleavage, affording the 48-electron compound [Ru ₃(μ₃-Se)(μ-PPh₂)₂(μ-C ₅H₄N)(μ₃-C₅H₄N)(CO) ₆] (1), the open triangular 50-electron nido clusters [Ru ₃(μ₃-Se)₂(CO)_9-n{P(2-C ₅H₄N)Ph₂}_n] (2 and 3, for n=1 and 2, respectively) and the octahedral 62-electron closo cluster [Ru ₄(μ₄-Se)₂(CO){μ-P,N-Ph ₂(2-C₅H₄N)P}] (4). The cluster 1 derives by the multiple fragmentation of two phosphine ligands on the metal triangle involving the P=Se and P-C bond cleavages. The molecular structure of 4 shows a short Ru?P non-bonding separation that can be viewed as a preliminary step towards the P-C bond cleavage. In the reactions with MCl ₂(PhCN)₂ (M=Pd, Pt) Ph₂(2-C₅H ₄N)PSe remains intact affording mononuclear neutral complexes of the type MCl₂{N,Se-Ph₂(2-C₅H₄N)PSe}. The crystal structure of the palladium derivative 5 has been determined by X-ray diffraction methods.

Full text of DOI:10.1016/S0020-1693(02)01518-9

Inorganica Chimica Acta 350 (2003) 421Á427
/
www.elsevier.com/locate/ica
Reactivity of Ph2(2-C5H4N)PSe towards Ru3(CO)12 and mononuclear
MCl2(PhCN)2 (MꢀPd or Pt) complexes
/
Daniele Belletti, Claudia Graiff, Chiara Massera, Giovanni Predieri,
Antonio Tiripicchio *
Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, Universita` di Parma, Parco Area delle Scienze 17/A,
I-43100 Parma, Italy
Received 8 July 2002; accepted 16 September 2002
Dedicated to the dear friend Pierre Braunstein in recognition of his brilliant career and of his important contributions to the development of
inorganic chemistry.
Abstract
The behavior of the Ph2(2-C5H4N)PSe ligand in the reactions with Ru3(CO)12 and the mononuclear complexes MCl2(PhCN)2
(MꢀPd or Pt) has been investigated. The reaction with Ru3(CO)12 is characterized by PÄSe bond cleavage, affording the 48-
electron compound [Ru3(m3-Se)(m-PPh2)2(m-C5H4N)(m3-C5H4N)(CO)6] (1), the open triangular 50-electron nido clusters [Ru3(m3-
Se)2(CO)9ꢁn{P(2-C5H4N)Ph2}n] (2 and 3, for nꢀ1 and 2, respectively) and the octahedral 62-electron closo cluster [Ru4(m4-
Se)2(CO){m-P,N-Ph2(2-C5H4N)P}] (4). The cluster 1 derives by the multiple fragmentation of two phosphine ligands on the metal
triangle involving the PÄSe and PÃC bond cleavages. The molecular structure of 4 shows a short Ruꢀ ꢀ ꢀP non-bonding separation
that can be viewed as a preliminary step towards the PÃC bond cleavage. In the reactions with MCl2(PhCN)2 (MꢀPd, Pt) Ph2(2-
/
/
/
/
/
/
/
C5H4N)PSe remains intact affording mononuclear neutral complexes of the type MCl2{N,Se-Ph2(2-C5H4N)PSe}. The crystal
structure of the palladium derivative 5 has been determined by X-ray diffraction methods.
# 2003 Elsevier Science B.V. All rights reserved.
Keywords: Ruthenium; Palladium; Platinum; Selenido-bridged complexes; Pyridyl-bridged complexes; Cluster compounds; Crystal structures
1. Introduction
C5H4P(Ph2)Se)2, towards iron and ruthenium carbonyl
clusters [2]. These reactions, taking advantage from the
Transition metal species may combine with main
group elements or related molecular fragments affording
a variety of interesting cluster compounds. Apart from
their fundamental significance as a class of complexes
owning peculiar chemical and structural properties, the
growing interest for these species derives from their
potential application both as catalysts and as precursors
for semiconductors with low band-gaps [1].
In recent years we have carried out systematic
investigations on the selenium transfer reactions by
tertiary phosphine and diphosphine selenides, such as
Ph3PSe, CH2(Ph2PSe)2, CH2CH2(Ph2PSe)2, and Fe(h5-
frailty of the PÄ
/
Se bond, provide a simple, one-step,
synthetic route to phosphine-substituted, mono- and
diselenido trinuclear clusters. In some cases these
reactions are very selective: the stoichiometric control
combined with different experimental conditions al-
lowed us to obtain the disubstituted trinuclear cluster
Ru3(m3-Se)2(CO)7(PPh3)2 in very high yield (ꢀ
/90%) [3].
On the other hand, they can lead to the formation of
different species not easily achievable by other routes,
such as the cubane-like cage complex [Ru4(m3-
Se)4(CO)10{m-P,P-(Ph2P)2CH2}] [4].
As a natural extension of these investigations, we have
studied the reactions of Group-8 carbonyl clusters with
tertiary phosphine selenides bearing heterocyclic groups,
namely 2-C5H4N(2-pyridyl), 2-C4H3S(2-thienyl) and 5-
(2-pyridyl)-2-thienyl. The presence of these groups was
* Corresponding author. Tel.: ꢂ
5557.
E-mail address: tiri@unipr.it (A. Tiripicchio).
/
39-0521-90 5418; fax: ꢂ39-0521-90
/
0020-1693/03/$ - see front matter # 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0020-1693(02)01518-9

422
D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á427
/
expected to lead to new reactivity patterns in cluster
growing processes, owing to the coordinating ability of
the hetero-atoms and to the possible release of hetero-
cyclic fragments. Actually, in these reactions the ex-
pected transfer of the chalcogenido atom to the metal
solutions) were recorded on Bruker instruments, AC
300 (1H) and CXP 200 (31P).
2.2. Reactions of Ph2(2-C5H4N)PSe with [Ru3(CO)12]
cluster can be followed by PÃ
/
C bond cleavage, affording
new selenidoÁphosphido clusters. In particular, in the
/
The experimental details are described in a previous
paper [8] along with the spectroscopical characterization
of 1 (main experimental details are given in Scheme 1).
case of thienyl and thienylpyridyl groups, the 48-
electron clusters [Ru3(m3-Se)(m-PPh2)(m-R)(CO)6{P(R)-
Ph2}] [Rꢀ
/
2-thienyl or 5-(2-pyridyl)-2-thienyl] were
Purification by crystallization (from a CH2Cl2ÁMeOH
/
obtained in good yields by a one-step synthesis [5,6].
Their molecular structures show the concomitant pre-
sence of the diphenylphosphido (bridging one side) and
selenido (capping) ligands on the same cluster core.
Regarding the pyridyl ring, the ligands Ph2(2-
C5H4N)P and Ph2(2-C5H4N)PS have already been
used in reactions towards transition metal complexes
[7]. More recently we have synthesized the selenium
derivative Ph2(2-C5H4N)PSe [8] and reacted it with
monometallic and bimetallic transition metal clusters
[8,9]. In the first case the reaction with Ru3(CO)12
affords the compound [Ru3(m3-Se)(m-PPh2)2(m-C5H4N)-
(m3-C5H4N)(CO)6] deriving from multiple fragmentation
of the phosphine. In the second case the bimetallic
[(CO)3Fe(m3-Se){Pt(CO)P(2-C5H4N)Ph2}2] was ob-
tained from the reaction with [Fe2(NO)2(CO)6-
Pt(PhCN)2].
mixture at 5 8C for some days) gave well formed crystals
of 3 and 4 suitable for X-ray analysis.
2.3. Cluster 2
FT IR (CH2Cl2) n(CO) (cmꢁ1): 2066, 2005, 1950.
31P{1H} NMR (CDCl3, 25 8C): d 20.9 (s).
2.4. Cluster 3
FT IR (CH2Cl2) n(CO) (cmꢁ1): 2047s, 2016, 1971,
1951sh. 31P{1H} NMR (CDCl3, ꢁ
/
30 8C): d 53.5 (s),
42.7 (s). H NMR (CDCl3, 25 8C): d 8.79 (d, 2H 2Py,
3J(H,H) 4 Hz), 7.67Á
7.31 (m, 26H 4Ph, 2Py).
1
/
The present paper, besides giving complete informa-
tion about the reaction of Ph2(2-C5H4N)PSe with
Ru3(CO)12, including the crystal structure of [Ru3(m3-
Se)2(CO)8{P-Ph2(2-C5H4N)P}] and [Ru4(m4-Se)2(CO)9-
{m-P,N-Ph2(2-C5H4N)P}], deals with the formation of
mononuclear Pt and Pd complexes of the type
2.5. Cluster 4
FT IR (CH2Cl2) n(CO) (cmꢁ1): 2051s, 2020, 2005sh,
1972. 31P{1H} NMR (CDCl3, 25 8C): d 18.1 (s). 1H
3
NMR (CDCl3, 25 8C): d 9.25 (d, 1H Py, J(H,H) 5.3
3
MCl2{N,Se-Ph2(2-C5H4N)PSe} in which the PÄ
/
Se
Hz), 7.79 (t, 1H Py, J(H,P)ꢀ3
7.39 (m, 12H 2Ph, Py).
/
J(H,H) 7.8 Hz), 7.53Á
/
bond cleavage is not observed.
2.6. Reaction of Ph2(2-C5H4N)PSe with
PdCl2(PhCN)2. Synthesis of PdCl2{N,Se-Ph2(2-
C5H4N)PSe} (5)
2. Experimental
2.1. General remarks
To a CH2Cl2 solution of PdCl2(PhCN)2 (0.130 g, 0.33
mmol) an equivalent quantity of Ph2(2-C5H4N)PSe
(0.120 g, 0.33 mmol) dissolved in dichloromethane was
added. The resulting orange solution was stirred for 1.5
h, then the solvent was removed in vacuo to obtain an
The starting reagents [Ru3(CO)12], KNCSe, Ph2(2-
C5H4N)P, Me3NO, MCl2(PhCN)2 (MꢀPd or Pt) were
/
pure commercial products (Aldrich and Fluka) and were
used as received. Ph2(2-C5H4N)PSe was synthesized
according to the literature procedure [8]. The solvents
(Carlo Erba) were dried and distilled by standard
techniques before use. All manipulations (prior to the
TLC separations) were carried out under dry nitrogen
by means of standard Schlenk-tube techniques. Elemen-
tal (C, H, N) analyses were performed with a Carlo Erba
EA 1108 automated analyzer. IR spectra (KBr discs or
CH2Cl2 solutions) were recorded on a Nicolet 5PC FT
spectrometer. 1H (300 MHz), 31P (81.0 MHz, 85%
H3PO4 as external reference) NMR spectra (CDCl3
orangeÁ
/
red powder. Purification by crystallization
MeOH mixture at 5 8C for some
days) gave well-formed red crystals of 5 (yield 57%),
(from a CH2Cl2Á
/
suitable for X-ray analysis.
Compound 5. Anal. Found: C, 39.5; H, 2.8; N, 2.7.
Calc. for C17H14Cl2NPPdSe: C, 39.4; H, 2.7; N, 2.7%.
FT IR (KBr, cmꢁ1): 773m, 754m, 731m, 717m, 700m,
692m, 683m (fingerprints region) 551s (nPSe). 31P{1H}
1
NMR (CDCl3): d 34.2 (s, with 77Se satellites, J(P,Se)
280 Hz).

D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á
/427
423
Scheme 1.
2.7. Reaction of Ph2(2-C5H4N)PSe with
PtCl2(PhCN)2. Synthesis of PtCl2{N,Se-Ph2(2-
C5H4N)PSe} (6)
gen atoms were introduced into the geometrically
calculated positions and refined riding on the corre-
sponding parent atoms. In the final cycles of refinement
a
weighting scheme wꢀ
CH2Cl2), wꢀ
1/[s2Fo2ꢂ(0.0982P)2], (4×
wꢀ
1/[s2Fo2ꢂ(0.1706P)2], (5), where Pꢀ
was used.
/
1/[s2Fo2ꢂ
/
(0.0820P)2], (3×
0.5CHCl3) and
(Fo2ꢂ2Fc2)/3
/
To a CH2Cl2 solution of PtCl2(PhCN)2 (0.207 g, 0.44
mmol) an equivalent quantity of Ph2(2-C5H4N)PSe
(0.150 g, 0.44 mmol) dissolved in dichloromethane was
added. The resulting yellow solution was stirred for 1.5
h, then the solvent was removed in vacuo to obtain an
yellow powder.
Compound 6. Anal. Found: C, 33.5; H, 2.2; N, 2.3.
Calc. for C17H14Cl2NPPtSe: C, 33.6; H, 2.3; N, 2.3%.
FT IR (KBr, cmꢁ1): 771m, 754m, 731m, 718m, 701m,
691sh, 684m (fingerprints region), 552s (nPSe).
/
/
/
/
/
/
/
3. Results and discussion
3.1. Reactions of Ph2(2-C5H4N)PSe with [Ru3(CO)12]
The reaction between Ph2(2-C5H4N)PSe and
[Ru3(CO)12] affords the products sketched in Scheme 1
(carbonyls omitted), whose distribution depends on the
reaction conditions.
2.8. Crystal structure determination of compounds 3×
/
CH2Cl2, 4×
/
0.5CHCl3 and 5
The intensity data of 3×
collected at room temperature on a Philips PW 1100 and
a Siemens AED single-crystal diffractometer using
/
CH2Cl2 and 4×
/
0.5CHCl3 were
Cluster 2 and 3 [nido core, seven skeletal electron
pairs (sep)] should be regarded as the primary products
of the attack of two selenide molecules to the metal
triangle, whereas cluster 4 (closo, 7 sep) should derive
from the nido homologous through thermal condensa-
tion and ligand exchange processes. Clusters of these
two families are generally the main products in the
reactions of iron and ruthenium carbonyls with phos-
phine selenides [2]. In addition, the starting triruthenium
graphite monochromated Mo Ka radiation (3×
/CH2Cl2
and 4×
/
0.5CHCl3) and graphite monochromated Cu Ka
radiation (5). Crystallographic and experimental details
for the structures are summarized in Table 1.
An empirical correction for absorption was made
[maximum and minimum value for the transmission
coefficient was 1.000 and 0.678, 1.000 0.753, 1.000 and
triangle undergoes multiple attack by two PÃ
/
C(Py)
0.457, respectively, for, 3×
/
CH2Cl2, 4×/0.5CHCl3 and 5]
groups, resulting in the formation of the unprecedented
compound [Ru3(m3-Se)(m-PPh2)2(m-C5H4N)(m3-C5H4N)-
(CO)6] (1), whose structure has been previously reported
[8]. This polynuclear species is characterized by the
presence of a nearly planar array of eleven atoms
formed by two roughly coplanar fused rings, i.e. the
heptaatomic RuPRuPRuCN cycle and one pyridyl ring.
This cluster has been obtained from Ph2(2-C5H4N)PSe
[10]. The structures were solved by Patterson and
Fourier methods and refined by full-matrix least-squares
procedures (based on Fo2) (SHELX-97) [11] first with
isotropic and then with anisotropic thermal parameters
in the last cycles of refinement for all the non-hydrogen
atoms excepting for the C and Cl atoms of the solvent in
3×
/
CH2Cl2 and in 4×
/
0.5CHCl3. The chloroform molecule
was found with the carbon atom disordered in two
positions with an occupancy factor of 0.25. The hydro-
through PÄ
/
Se and PÃ
/
C(Py) bond cleavages, the latter
process contrasting with the reactivity of Ph2(2-

424
D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á427
/
Table 1
Crystal data and structure refinement for 3×
/
CH2Cl2, 4×0.5CHCl3, and 5
/
3×CH2Cl2
/
4×
/
0.5CHCl3
5
Formula
Ru3Se2P2N2O7C41H28
×
/
CH2Cl2
Ru4Se2PNO9C26H14
1137.24
monoclinic
P21/c
×
/
0.5CHCl3
PdSePNCl2C17H14
519.52
triclinic
Formula weight
Crystal system
Space group
1268.65
monoclinic
P21/n
P/1
˚
a (A)
11.041(4)
30.662(5)
14.495(4)
90
10.125(3)
17.191(4)
20.980(5)
90
8.337(3)
9.142(3)
12.414(5)
98.71(2)
103.99(3)
89.99(2)
2313(1)
2
˚
b (A)
˚
c (A)
a (8)
b (8)
111.31(2)
90
102.94(3)
90
g (8)
3
V (A )
˚
4572(2)
4
1.843
3559.0(16)
4
2.122
Z
Dcalc (g cmꢁ3
F(000)
)
1.903
504
2464
2148
Crystal size
m (cmꢁ1
0.15ꢃ
28.07
13 797
/
0.12ꢃ
/
0.15
0.11ꢃ
39.15
8830
/
0.11ꢃ
/
0.12
0.18ꢃ
140.64
3417
/
0.22ꢃ0.25
/
)
Reflections collected
Reflections unique
Observed reflections
13 337 [Rint
ꢀ
/
0.0453]
8615 [Rint
4389 [I ꢀ
R1ꢀ0.0502, wR2ꢀ
R1ꢀ0.1111, wR2ꢀ
ꢀ/0.0338]
3417 [Rint
2269 [I ꢀ
R1ꢀ0.0767, wR2ꢀ
R1ꢀ0.0970, wR2ꢀ
ꢀ/0.000]
8513 [I ꢀ
R1ꢀ0.0436, wR2ꢀ
R1ꢀ0.0871, wR2ꢀ
/
2s(I)]
/
2s(I)]
/2s(I)]
Final R indices, [I ꢀ
R indices (all data)
/2s(I)]
/
/
0.1205
/
/
0.1506
/
/
0.2052
0.2213
/
/0.1475
/
/0.1704
/
/
R1ꢀ
/
ajjFojꢁ
/
jFcjj/ajFoj; wR2ꢀ
/
[a[w(Fo2ꢁ
/
Fc2)2]/a[w(Fo2)2]]1/2
.
C5H4N)P towards [Ru3(CO)12], which undergoes PÃ
/
C(Ph) rupture [12].
Clusters 2 and 3 possess the well known Ru3(m3-Se)2
core and they can be described as a squared pyramid
with two ruthenium and two selenium atoms alternating
on the basal plane and the third ruthenium atom at the
apex of the pyramid. In 2 only one phosphine replaces a
carbonyl group, whereas in 3 two phosphine ligands
coordinate two ruthenium atoms at the base of the
pyramid, replacing two carbonyls. The structure of 3 has
been fully elucidated by the X-ray analysis, while that of
2 has been recognized by comparison of its spectro-
scopic data with those of the analogous compound
[Ru3(m3-Se)2(CO)8(PPh3)] [2].
In the crystals of 3, [Ru3(m3-Se)2(CO)7{P-Ph2(2-
C5H4N)P}2] complexes and dichloromethane molecules
of solvation are present. A view of the structure of 3 is
shown in Fig. 1 together with the atomic labeling
system.
Fig. 1. View of the molecular structure of 3 together with the atomic
numbering system. Thermal ellipsoids are drawn at 30% probability
level.
Selected bond distances and angles are given in Table
2. The structure of 3 is very similar to that of the
disubstituted analogue Ru3(m3-Se)2(CO)7(PPh3)2 [3]. In
comparable to that of the unsubstituted analogue
˚
Ru3(m3-Se)2(CO)9 [13], where the values of the RuÃ
/
Ru
3 the Ru-Se bonds range from 2.491(1) to 2.537(1) A
˚
˚
bonds are 2.817(2) and 2.826(1) A and those of the RuÃ
/
(2.491(1) to 2.536(2) A in Ru3(m3-Se)2(CO)7(PPh3)2); the
/
2.526(1) A. The 31P
˚
Se bonds are in the range 2.473(1)Á
two RuÃ
2.813(1) and 2.839(1)
Ru3(m3-Se)2(CO)7(PPh3)2), whereas the RuÃ
/
Ru metal bond distances are comparable,
˚
A
˚
A in
NMR spectrum of cluster 3 recorded at 243 K exhibits
two singlets, which collapse at 25 8C. This behavior
indicates the non equivalence in solution of the two
phosphorus atoms of the phosphine ligands, which
occupy pseudo axial and pseudoequatorial non equiva-
lent positions also in the solid state.
(2.801(2)Á/2.855(2)
/
P ones,
˚
A
˚
2.371(4) A in
2.306(1) and 2.354(2)
Ru3(m3-Se)2(CO)7(PPh3)2), differ remarkably because
of the different trans influence of the RuÃRu and
RuÃSe bonds [3]. The structure of 3 is obviously also
(2.326(3)Á
/
/
/

D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á
/427
425
Table 2
Table 3
˚
˚
List of selected bond lengths (A) and angles (8) for 3
List of selected bond lengths (A) and angles (8) for 4
Bond lengths
Bond lengths
Ru(1)Ã
Ru(1)Ã
Ru(1)Ã
Ru(1)Ã
Ru(2)Ã
Ru(2)Ã
Ru(2)Ã
Ru(3)Ã
Ru(3)Ã
Ru(3)Ã
/
P(1)
2.3056(15)
2.5027(8)
2.5140(8)
2.8134(10)
2.5299(8)
2.5376(11)
2.8395(7)
2.3536(16)
2.4915(8)
2.5133(9)
1.822(6)
Ru(1)Ã
Ru(1)Ã
Ru(2)Ã
Ru(3)Ã
Ru(1)Ã
Ru(1)Ã
Ru(2)Ã
Ru(2)Ã
Ru(3)Ã
Ru(3)Ã
Ru(4)Ã
Ru(4)Ã
Ru(3)Ã
Ru(4)Ã
P(1)Ã
N(1)Ã
/
Ru(4)
Ru(2)
Ru(3)
Ru(4)
Se(2)
Se(1)
Se(1)
Se(2)
Se(1)
Se(2)
Se(1)
Se(2)
P(1)
2.7378(14)
2.7705(13)
2.8080(15)
2.8156(12)
2.6141(12)
2.6587(13)
2.5460(13)
2.5650(12)
2.5505(12)
2.5682(13)
2.4811(12)
2.5815(13)
2.303(3)
/
Se(2)
Se(1)
Ru(2)
Se(1)
Se(2)
Ru(3)
P(2)
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Se(2)
Se(1)
/
/
/
P(1)Ã
P(1)Ã
P(1)Ã
P(2)Ã
P(2)Ã
P(2)Ã
/
C(14)
/
/
C(8)
1.841(5)
/
/
C(20)
C(37)
C(31)
C(25)
1.854(5)
1.834(6)
1.841(6)
/
/
/N(1)
2.101(7)
/
/
C(22)
1.825(9)
/
1.841(5)
/
C(22)
1.341(10)
Bond angles
Se(2)ÃRu(1)Ã
P(1)ÃRu(1)ÃRu(2)
Se(1)ÃRu(2)ÃSe(2)
Ru(1)ÃRu(2)ÃRu(3)
P(2)ÃRu(3)ÃSe(1)
Se(2)ÃRu(3)ÃSe(1)
P(2)ÃRu(3)ÃRu(2)
Ru(3)ÃSe(1)Ã
Ru(3)ÃSe(2)Ã
Bond angles
Se(2)ÃRu(1)Ã
Se(1)ÃRu(2)Ã
Se(1)ÃRu(3)Ã
Se(1)ÃRu(4)Ã
Ru(4)ÃRu(1)Ã
Ru(1)ÃRu(2)Ã
Ru(2)ÃRu(3)Ã
Ru(1)ÃRu(4)Ã
Ru(4)ÃSe(1)Ã
Ru(3)ÃSe(1)Ã
Ru(2)ÃSe(2)Ã
Ru(3)ÃSe(2)Ã
P(1)ÃRu(3)Ã
N(1)ÃRu(4)Ã
C(22)ÃP(1)ÃRu(3)
C(22)ÃN(1)Ã
N(1)ÃC(22)Ã
/
/
Se(1)
79.89(3)
151.49(4)
78.93(2)
85.32(2)
167.12(4)
80.11(3)
111.21(4)
99.27(3)
100.17(3)
/
/
Se(1)
Se(2)
Se(2)
Se(2)
77.67(4)
80.63(4)
80.48(4)
81.53(4)
88.99(4)
91.83(4)
86.71(4)
92.36(4)
100.34(4)
100.56(4)
97.21(4)
101.29(4)
157.99(7)
151.61(18)
115.2(3)
115.9(6)
114.6(6)
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Ru(2)
Ru(3)
Ru(4)
Ru(3)
/
/
/
/
/
/
/
/
/
/
Ru(1)
Ru(1)
/
/
/
/
/
/
Ru(2)
Ru(1)
Ru(4)
Ru(1)
/
/
/
/
/
/
In the crystals of 4, [Ru4(m4-Se)2(CO)9{m-P,N-Ph2(2-
C5H4N)P}] complexes and chloroform molecules of
solvation are present. Complex 4 belongs to the family
of Ru4(m4-Se)2 closo clusters with 62 electrons and seven
skeletal electron pairs. Fig. 2 shows the structure of 4
together with the atomic numbering system. Selected
bond distances and angles are given in Table 3.
The cluster adopts a distorted closo-octahedral geo-
metry with the four Ru atoms occupying the equatorial
positions and the two Se atoms the apices. Two
/
/
Ru(2)
Se(1)
/
/
/
/
/
/
Ru(4)
/
/
P(1)
carbonyls bridge two adjacent edges of the Ru4 square
plane, resulting in a shortening of the Ru1ÃRu2 and
Ru1ÃRu4 bond distances [2.770(1) and Ru1ÃRu4
2.738(1) A, respectively] [3,14,15] with respect to the
/
/
/
˚
˚
other two [2.808(1) and 2.816(1) A]. The chalcogen
˚
atoms Se1 and Se2 lie, respectively, 1.634(4) A below
˚
and 1.671(4) A above the Ru4 mean plane, the eight
RuÃSe bond lengths ranging from 2.481(1) to 2.659(1)
/
˚
A. The structure is comparable to that of cluster
[Ru4(m4-Se)2(CO)9{m-P,P-(Ph2P)2CH2}] [15] in which a
bisdiphenilphosphinomethane ligand (dppm) coordi-
nates two adjacent ruthenium atoms through the
phosphorous atoms. In 4 the phosphine bridges a RuÃ
/
Ru edge via the P and N atoms (Ru3Ã
/
P1 and Ru4Ã
/
N1
˚
bond distances: 2.303(3) and 2.101(7) A, respectively,
see Fig. 3)
The Ph2(2-C5H4N)P ligand is coordinated in such a
˚
way that the P1 atoms lies at a distance of 3.030(3) A
˚
from the Ru4 atom, and is slightly deviated, 0.24(1) A,
from the mean plane defined by the four metal atoms;
Fig. 2. View of the molecular structure of 4 together with the atomic
numbering system. Thermal ellipsoids are drawn at 30% probability
level.
the N1Ã
/
C22Ã
/
P1 bond angle [114.6(6)8] is quite narrow
with respect to the ideal value of 1208. The short

426
D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á427
/
Fig. 3. Coordination mode of Ph2(2-C5H4N)P in [Ru4(m4-Se)2(CO){m-
P,N-Ph2(2-C5H4N)P}]; bond distances are given in A.
Fig. 4. View of the molecular structure of 5 together with the atomic
numbering system. Thermal ellipsoids are drawn at 30% probability
level.
˚
interaction Ruꢀ ꢀ ꢀP can be viewed as a preliminary step
towards the PÃ
/C bond cleavage, for the formation of a
A view of the structure of 5 is shown in Fig. 4. The
most important bond distances and angles are given in
Table 4.
In the mononuclear neutral palladium complex the
Ph2(2-C5H4N)PSe acts as a chelating ligand through the
Se1 and N1 atoms. The selenide phosphine ligand forms
m2-bridged PPh2 phosphine ligand. In this regard it is
interesting to note that the Ruꢀ ꢀ ꢀP distance lies among
the dozen shortest Mꢀ ꢀ ꢀP interactions observed in about
ninety di- or polynuclear complexes containing bridging
Ph2(2-C5H4N)P reported in the Cambridge Data Base
˚
(2.938, 3.672, 3.265 A min, max and mean values,
respectively).
a five-membered chelating ring, with Pd1Ã
/
Se1 and Pd1Ã
/
˚
N1 bond distances of 2.399(1) and 2.065(7) A, respec-
tively. The coordination geometry around the palladium
atom is square planar [maximum deviation from the
mean plane defined by Cl1, Cl2, Se1, N1, Pd1 is 0.128(3)
3.2. Reaction of Ph2(2-C5H4N)PSe with MCl2(PhCN)2
(MꢀPd or Pt)
/
˚
˚
Se bond distance [2.146(2) A] is
comparable with those found in other complexes with
A for Cl1 atom]. The PÃ
/
Reactions between mononuclear metal complexes and
phosphine selenides have already been reported in the
literature, as in the case of the dppm selenide (dppmse)
ligand [16]. In fact, the reaction of dppmse with
metal(II) chlorides are simple coordination processes
leading to complexes of the type [M{P,Se-
Table 4
˚
List of selected bond lengths (A) and angles (8) for 5
Bond lengths
Pd(1)Ã
Pd(1)Ã
Pd(1)Ã
Pd(1)Ã
Se(1)Ã
N(1)ÃC(5)
P(1)ÃC(5)
/
N(1)
Cl(2)
Cl(1)
Se(1)
2.065(7)
2.272(3)
2.348(3)
2.3985(14)
2.146(2)
1.361(11)
1.805(9)
/
Ph2PCH2Ph2PSe}2]Cl2 (Mꢀ
reactions of Ph2(2-C5H4N)PSe with MCl2(PhCN)2
(MꢀPd or Pt) it was possible to isolate and characterize
the complexes [M{N,Se-Ph2(2-C5H4N)PSe}Cl2] (5 and
6, respectively, for MꢀPd and Pt), in which the ligand
/
Ni, Co or Pd). From the
/
/
/P(1)
/
/
/
/
Bond angles
N(1)ÃPd(1)Ã
N(1)ÃPd(1)Ã
Cl(2)ÃPd(1)Ã
N(1)ÃPd(1)ÃSe(1)
Cl(2)ÃPd(1)Ã
Cl(1)ÃPd(1)Ã
P(1)ÃSe(1)Ã
C(5)ÃN(1)Ã
C(5)ÃP(1)ÃSe(1)
N(1)ÃC(5)ÃP(1)
chelates the metal center via the selenium and the
nitrogen atoms. Coordination through Se is suggested
/
/
Cl(2)
174.4(2)
93.4(2)
/
/Cl(1)
by the significant shift of the PÄ
/
Se stretching band to
/
/Cl(1)
90.94(12)
91.20(19)
84.76(10)
173.88(9)
90.48(7)
121.4(6)
105.8(3)
116.0(6)
low frequencies due to the MÃ
/
Se interaction (569 cmꢁ1
/
/
in free Ph2(2-C5H4N)PSe, 551 cmꢁ1 in the complexes).
On the other hand, coordination through P is evidenced
by the remarkable lowering of the 1J(P,Se) coupling
constant from 720 to 280 Hz in the 31P{1H} NMR
spectrum, while the chemical shift is only slightly
affected (d 34.2 in complex 5, d 31.5 in the free ligand).
/
/Se(1)
/
/Se(1)
/
/
Pd(1)
/
/
Pd(1)
/
/
/
/

D. Belletti et al. / Inorganica Chimica Acta 350 (2003) 421Á
/427
427
Raithby (Eds.), Metal Clusters in Chemistry, vol. 1, VCH,
Weinheim, 1999, p. 163.
coordinated mono- and diphosphine selenides (2.145(3)
˚
[17], 2.183(3) and 2.189(3) [18], 2.186(3) and 2.200(2) A
[19]), and significantly longer than those found in non-
coordinated mono- and diphosphine selenides (2.103(3)
and 2.097(4) [20], 2.108(1) [21], 2.111(3) [22], 2.085(1)
˚
and 2.101(1) A [23]). The chelation ring exhibits an
envelope conformation with the Se1 atom deviating of
˚
0.968(1) A from the mean plane passing through the
other four atoms of the ring.
[2] D. Cauzzi, C. Graiff, G. Predieri, A. Tiripicchio, in: P. Braun-
stein, L. Oro, P. Raithby (Eds.), Metal Clusters in Chemistry, vol.
1, VCH, Weinheim, 1999, p. 193.
[3] P. Baistrocchi, D. Cauzzi, M. Lanfranchi, G. Predieri, A.
Tiripicchio, M. Camellini Tiripicchio, Inorg. Chim. Acta 235
(1995) 173.
[4] D. Cauzzi, C. Graiff, M. Lanfranchi, G. Predieri, A. Tiripicchio,
J. Chem. Soc., Dalton Trans. (1995) 2321.
[5] D. Cauzzi, C. Graiff, C. Massera, G. Predieri, A. Tiripicchio,
Inorg. Chim. Acta 300Á302 (2000) 471.
/
[6] D. Cauzzi, C. Graiff, C. Massera, G. Predieri, A. Tiripicchio, J.
Cluster Sci. 12 (2001) 259.
4. Supplementary material
[7] (a) M.E. Olmos, A. Schier, H. Schmidbaur, Z. Naturforsch., T. B
52 (1997) 385;
(b) G.R. Newkome, Chem. Rev. 93 (1993) 2067;
The supplementary material for the structures in-
cludes the lists of atomic coordinates for the non-H
atoms, of calculated coordinates for the hydrogen
atoms, of anisotropic thermal parameters and complete
lists of bond lengths and angles. The details of the
crystal structure investigations have been deposited with
the Cambridge Crystallographic Data Center CCDC
(c) Z.-Z. Zhang, H. Cheng, Coord. Chem. Rev 147 (1996) 1.
[8] D. Cauzzi, C. Graiff, C. Massera, G. Predieri, A. Tiripicchio, Eur.
J. Inorg. Chem. (2001) 721.
[9] C. Graiff, A. Ienco, C. Massera, C. Mealli, G. Predieri, A.
Tiripicchio, F. Ugozzoli, Inorg. Chim. Acta 330 (2002) 95.
[10] (a) N. Walker, D. Stuart, Acta Crystallogr., A 39 (1983) 158F;
(b) F. Ugozzoli, Comput. Chem. 11 (1987) 109.
[11] (a) G.M. Sheldrick, SHELXL-93, a Program for Crystal Structure
Determination, University of Gottingen, Gottingen, Germany,
Nos. 168273 (3×
/
CH2Cl2), 168274 (4×
/0.5CHCl3) and
¨
¨
168275 (5). Copies of the data can be obtained free of
charge on application to The Director, CCDC, 12
1993;
(b) G.M. Sheldrick, SHELXL-97, Program for Crystal Structure
Refinement, University of Gottingen, Gottingen, Germany, 1997.
¨
¨
Union Road, Cambridge, CB2 1EZ, UK (fax: ꢂ44-
/
[12] N. Lugan, G. Lavigne, J.-J. Bonnet, Inorg. Chem. 26 (1987) 585.
[13] T.M. Layer, J. Lewis, A. Martin, P.R. Raithby, W.-T. Wong, J.
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[14] P. Baistrocchi, M. Careri, D. Cauzzi, C. Graiff, M. Lanfranchi, P.
Manini, G. Predieri, A. Tiripicchio, Inorg. Chim. Acta 252 (1996)
367.
Acknowledgements
[15] D. Cauzzi, C. Graiff, G. Predieri, A. Tiripicchio, C. Vignali, J.
Chem. Soc., Dalton Trans. (1999) 237.
Financial support from the Ministero dell’Universita`
e della Ricerca Scientifica e Tecnologica (Rome, Cofin
2000) is gratefully acknowledged. The facilities of the
Centro Interdipartimentale di Misure ‘G. Casnati’
(Universita` di Parma) were used to record the NMR
and mass spectra.
[16] D. Cauzzi, C. Graiff, M. Lanfranchi, G. Predieri, A. Tiripicchio,
Inorg. Chim. Acta 273 (1998) 320.
[17] G. Siasios, E.R.T. Tiekink, J. Chem. Soc., Dalton Trans. (1996)
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[18] P. Bhattacharyya, J. Novosad, J. Phillips, A.M.Z. Slawin, D.J.
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