Osmacycles containing the {(Ph2PE)2N}- ligand (E = S or Se): Synthesis and crystal structures

Article abstract of DOI:10.1016/S0022-328X(02)01967-8

The reaction of (Ph₂P)₂NH (dppa) or Ph₂PN(H)P(O)Ph₂ (HL) with [Os(η⁶-cym)Cl₂]₂ [cym = p-CH₃C₆H₄CH(CH₃)₂] in THF affords the orange, neutral mononuclear complexes [OsCl₂(η⁶-cym)P-dppa] (1a) or [OsCl₂(η⁶-cym)P-HL] (2), respectively, bearing a pendant -PPh₂ or -P(O)Ph₂ group. Complex 1a isomerises smoothly in CDCl₃ solution to give the cationic P,P′-chelate complex [OsCl(η⁶-cym)P,P′-dppa]Cl (1b). Compound 2 can further be converted into the yellow P,O-chelate complexes [OsCl(η⁶-cym)P,O-HL][BF₄] (3) and [OsCl(η⁶-cym)P,O-L] (4) [L = Ph₂PNP(O)Ph₂] upon treatment with either Ag[BF₄] or ¹BuOK, respectively. Chloro bridge cleavage of [Os(η⁶-cym)Cl₂]₂ with the potassium salt of either {Ph₂P(S)}₂N^- or {Ph²P(Se)}₂N^- yields the orange neutral complexes [OsCl(η⁶-cym){E,E′-Ph₂P(E)}₂N] (E = S 5, E = Se 6). All new compounds were characterised by a combination of NMR spectroscopy (¹H and ³1P{¹H}), IR spectroscopy, microanalysis and X-ray crystallography. The five- (Os-P-N-P-O) and six-membered (Os-E-P-N-P-E) osmacycles represent the first examples of crystallographically characterised osmium(II) metallocycles.

Full text of DOI:10.1016/S0022-328X(02)01967-8

Journal of Organometallic Chemistry 664 (2002) 85ꢃ93
/
www.elsevier.com/locate/jorganchem
Osmacycles containing the {(Ph2PE)2N}ꢀ ligand (Eꢁ
synthesis and crystal structures
/
S or Se):
Jonathan Parr 1, Martin B. Smith ꢂ, Mark R.J. Elsegood
Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
Received 22 August 2002; received in revised form 20 September 2002; accepted 20 September 2002
Abstract
The reaction of (Ph2P)2NH (dppa) or Ph2PN(H)P(O)Ph2 (HL) with [Os(h6-cym)Cl2]2 [cymꢁ
affords the orange, neutral mononuclear complexes [OsCl2(h6-cym)P-dppa] (1a) or [OsCl2(h6-cym)P-HL] (2), respectively, bearing
a pendant ÃPPh2 or ÃP(O)Ph2 group. Complex 1a isomerises smoothly in CDCl3 solution to give the cationic P,P?-chelate complex
[OsCl(h6-cym)P,P?-dppa]Cl (1b). Compound 2 can further be converted into the yellow P,O-chelate complexes [OsCl(h6-cym)P,O-
HL][BF4] (3) and [OsCl(h6-cym)P,O-L] (4) [LꢁPh2PNP(O)Ph2] upon treatment with either Ag[BF4] or tBuOK, respectively.
Chloro bridge cleavage of [Os(h6-cym)Cl2]2 with the potassium salt of either {Ph2P(S)}2Nꢀ or {Ph2P(Se)}2Nꢀ yields the orange
neutral complexes [OsCl(h6-cym){E,E?-Ph2P(E)}2N] (Eꢁ
S 5, EꢁSe 6). All new compounds were characterised by a combination
of NMR spectroscopy (1H and 31P{1H}), IR spectroscopy, microanalysis and X-ray crystallography. The five- (OsÃ
PÃNÃPÃO) and
six-membered (OsÃEÃPÃNÃPÃE) osmacycles represent the first examples of crystallographically characterised osmium(II)
metallocycles.
/p-CH3C6H4CH(CH3)2] in THF
/
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# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Arene complexes; Crystal structure; Inorganic heterocycle; Osmacycle; NMR spectroscopy; Phosphorus ligands
1. Introduction
[19] and Zn [19], rare-earth metals [20,21] and Group 16
heavy elements [22]. To the best of our knowledge these
ligands have not been investigated in detail with osmium
although Leung et al. recently reported some os-
The coordination and organometallic chemistry of
phosphorus based ligands bearing a PÃ
continues to attract much interest [1ꢃ6]. We, and others,
/
NÃ
/P skeleton
mium(VI) complexes of {Ph2P(E)}2N (EꢁS or Se)
/
/
[23,24]. The same group [14,15], and ourselves [25],
have also described some complexes with ruthenium.
We wish to describe here our studies using ligands
have reported on studies with HN(PPh2)2 [7] which
serves as a useful precursor to the phosphine oxide
Ph2PN(H)P(O)Ph2 (HL) [8,9] and the chalcogenides
bearing a PÃ
/
NÃ
/
P skeletal backbone in the preparation
HN{P(E)Ph2}2 (EꢁO, S, Se) [10,11]. The latter com-
/
of a series of new ‘‘half sandwich’’ osmium(II) com-
plexes and include the X-ray structures of six examples.
pounds can readily be deprotonated affording
N{P(E)Ph2}2ꢀ ligands [10,11] in which various ligating
modes have been observed, the most common of which
is the E,E?-chelation mode. Recent interest in these
anionic ligands has resulted in several publications
addressing coordination studies with V [12], Cr [12],
2. Experimental
Mn [13], Ru [14ꢃ16], Rh [16], Ir [16,17], Pd [18,19], Pt
/
2.1. Materials
ꢂ Corresponding author. Tel: ꢄ
223-925
E-mail address: m.b.smith@lboro.ac.uk (M.B. Smith).
/
44-1509-222-553; fax: ꢄ44-1509-
/
All reactions were carried out under an atmosphere of
dry oxygen-free nitrogen. All solvents were distilled
prior to use. The compounds (Ph2P)2NH [7],
1
Present address: Department of Chemistry, Yale University, 225
Prospect Street, New Haven, CT 06520, USA.
Ph2PN(H)P(O)Ph2 [8], K{Ph2P(E)}2N (Eꢁ
/
S [10], Eꢁ
/
0022-328X/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
PII: S 0 0 2 2 - 3 2 8 X ( 0 2 ) 0 1 9 6 7 - 8

86
J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ93
/
Se [11]) and [Os(h6-cym)Cl2]2 [26] were prepared accord-
ing to published procedures.
Bruker AXS SMART and SAINT for diffractometer
control and frame integration [27], Bruker SHELXTL
for structure solution, refinement and molecular gra-
phics [28], and local programs.
2.2. Instrumentation
IR spectra were recorded as KBr pellets over the
2.4. Preparation of complexes
range 4000ꢃ
/
200 cmꢀ1 using a Perkinꢃ
Elmer system
/
2000 FT spectrometer. The 1H-NMR spectra were
recorded on a Bruker AC250 FT spectrometer (250
MHz) with chemical shifts (d) reported relative to
external Me4Si (see Table 1). The 31P{1H}-NMR spectra
were recorded on a JEOL FX90Q spectrometer (36.2
MHz) with chemical shifts (d) reported relative to
2.4.1. OsCl2(h6-cym)P-Ph2PN(H)PPh2 (1a)
To a solution of [Os(h6-cym)Cl2]2 (0.025 g, 0.031
mmol) in THF (10 ml) was added HN(PPh2)2 (0.026 g,
0.068 mmol) as a solid and the reaction stirred at room
temperature for 6 h. The solvent was removed under
vacuum and the yellow residue extracted into CHCl3 (2
ml). The extract was filtered through Celite to remove
insoluble material before addition of 60:80 petroleum
(10 ml) to give 1a as a yellow microcrystalline solid.
Yield: 0.042 g, 82%. IR: 3318, 3286 n(NH); 920, 906
1
external 85% H3PO4; all H-NMR spectra (250 or 400
MHz) were recorded in CDCl3 solutions unless other-
wise stated. Elemental analyses (PerkinꢃElmer 2400
/
CHN Elemental Analyzer) were performed by the
Loughborough University Analytical Service within
the Department of Chemistry.
n(PN) cmꢀ1
.
The isomer [OsCl(h6-cym)P,P?-
Ph2PN(H)PPh2]Cl (1b) was observed immediately, as
the only phosphorus containing species, upon addition
of NEt3 to a CDCl3 solution of 1a.
2.3. X-ray crystallography
All measurements were made on a Bruker AXS
SMART 1000 CCD area-detector diffractometer, at 150
2.4.2. OsCl2(h6-cym)P-Ph2PN(H)P(O)Ph2 (2)
To a solution of [Os(h6-cym)Cl2]2 (0.086 g, 0.109
mmol) in THF (10 ml) was added Ph2PN(H)P(O)Ph2
(0.088 g, 0.219 mmol) as a solid. The solution was stirred
K, using graphite-monochromated Moꢃ
/
Ka radiation
˚
(lꢁ
/
0.71073 A) and narrow frame exposures (0.38) in v.
Cell parameters were refined from the observed (v)
angles of all strong reflections in each data set.
Intensities were corrected semiempirically for absorp-
tion based on symmetry-equivalent and repeated reflec-
tions. The structures were solved by direct methods
(Patterson synthesis for 1a, 3 and 5) and refined on F2
values for all unique data by full-matrix least-squares.
Table 2 gives further details. All non-hydrogen atoms
were refined anisotropically. H-atoms, located in differ-
ence maps, were constrained with a riding model except
H(1), H(2) and H(3) in 3 where the coordinates were
freely refined; U(H) was set to 1.2 (1.5 for methyl
groups) times Ueq for the parent atom. Complex 2
contains two similar molecules in the asymmetric unit.
The asymmetric unit of 3 contains two cations, two
anions and one MeOH of crystallisation. In 4 the two
phenyl rings on P(2) have all six carbon atoms dis-
ordered over two sets of positions, roughly equally
occupied. This disorder was modelled with restraints on
geometry and displacement parameters. In 5 C(43) was
disordered over two sets of positions with ca. 75:25
occupancy ratio and was modelled as described above.
There are two molecules with minor conformational
differences in the asymmetric unit. Compound 6 has one
for ca. 5ꢃ10 min whereupon an orange solid deposits.
/
After stirring the mixture for ca. 2 h, the volume of the
solvent was reduced by half and 60:80 petroleum (10 ml)
added. Solid 2 was collected by suction filtration and
dried in vacuo. Yield: 0.152 g, 88%. IR: 3253 n(NH);
1214 n(PO); 931 n(PN) cmꢀ1
.
2.4.3. [OsCl(h6-cym)P,O-Ph2PN(H)P(O)Ph2][BF4]
(3)
To a suspension of Ag[BF4] (0.030 g, 0.154 mmol) in
CH2Cl2 (20 ml) was added 2 (0.103 g, 0.129 mmol) as a
solid. After stirring the mixture for 2 h in the dark, AgCl
was removed over a Celite plug. The volume was
reduced in vacuo to ca. 1ꢃ2 ml and Et2O (20 ml) added.
/
The solid was collected by suction filtration and dried in
vacuo. Yield: 0.085 g, 76%. IR: 3226 n(NH); 1130
n(PO); 923 n(PN) cmꢀ1
.
Compound 3 could also be prepared by protonation
of 4 with HBF4×
OEt2 (31P{1H}-NMR evidence).
/
2.4.4. [OsCl(h6-cym)P,O-Ph2PNP(O)Ph2] (4)
To a suspension of 2 (0.045 g, 0.565 mmol) in CH3OH
(HPLC grade, 0.5 ml) was added tBuOK (0.008 g,
0.0713 mmol). After stirring for 5 min the crude solid
was filtered and dried briefly. The solid was dissolved in
CH2Cl2 (4 ml) and 60:80 petroleum (10 ml) added. Solid
4 was collected by suction filtration and dried in vacuo.
Yield: 0.025 g, 56%. IR: 1127 n(PO); 1009, 996 n(PN)
phenyl ring [C(11)ꢀC(16)] disordered over two sets of
/
positions with C(11) common to both and ca. 65:35
occupancy ratio. There is also a CHCl3 molecule
disordered over two sets of positions with ca. 60:40
occupancy ratio. These two disordered groups were
modelled as described above. Programs used were
cmꢀ1
.

Table 1
Selected analytical and spectroscopic data for 1aꢃ
/
6
Compound 31P (ppm) 1H(arom) (ppm) 1H(cym) (ppm)
1H{CH(CH3)2}
(ppm)
1H(CH3)
(ppm)
1H{CH(CH3)2} (ppm) C (calc)
H (calc)
N (calc)
m/z
a
b
d
h
1a
2
25.6, 23.9 7.91ꢃ
/
7.23
7.14
7.21
7.11
6.99
6.96
5.49 d, 5.36 d (4.0)
5.39 d, 5.23 d (4.0)
2.41 sep (6.8)
2.26 sep (8.0)
5.76 d, 5.52 d, 5.40 d, 5.26 d 2.35 sep (6.8)
2.09 s
1.98 s
2.05 s
2.04 s
1.79 s
1.83 s
0.89 d (6.8)
0.79 d (8.0)
0.98 d (6.8)
46.45 (46.70)
3.89 (4.05) 2.86 (1.56) 781 [M]
50.90 (51.25) 4.40 (4.45) 1.50 (1.75) 797 [M]
c
20.6, 20.3 7.82ꢃ
/
e
3
70.2, 51.3 7.94ꢃ
/
47.50 (48.15) 4.15 (4.15) 1.65 (1.65) 762 [MꢀBF4]
f
4
79.0, 46.5 8.01ꢃ
/
5.69 d, 5.33 dd, 4.74 d
5.34 d, 5.20 d (2.5)
5.29 d, 5.16 d (2.5)
2.27 sep
2.52 sep (5.0)
2.56 sep (5.0)
1.06 d (6.8), 0.66 d (7.2) 53.60 (53.70) 4.35 (4.50) 1.65 (1.85) 760 [M]
50.65 (50.50) 4.20 (4.25) 1.80 (1.75) 774 [MꢀCl]
45.15 (45.25) 3.70 (3.80) 1.50 (1.55) 867 [MꢀCl]
5
37.1
26.5
8.12ꢃ
/
1.04 d (5.0)
1.02 d (5.0)
g
6
8.13ꢃ
/
a
b
c
2J(PP) 22 Hz.
5.01 [2J(PH) 8.0 Hz], NH.
2J(PP) not observed.
d
e
6.26 [2J(PH) 8.0, 4.0 Hz], NH.
2J(PP) 26 Hz.
2J(PP) 33 Hz.
J(PSe) 558 Hz.
f
g
h
Contains 1 mol. CHCl3. dꢁdoublet, sepꢁseptet, sꢁsinglet.

88
J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ93
/
Table 2
Crystal data for 1aꢃ6
/
1a
2
3
4
5
6
Empirical formula
C
34H35Cl2-
C34H35Cl2NOOsP2 C34H35BClF4NO- C34H34ClNO-
C34H34Cl-
NOsP2S2
808.33
C34H34Cl-
NOsP2Se2×CHCl3
1021.50
NOsP2×CHCl3
900.04
Orange
OsP2×0.5CH3OH
864.05
Yellow
OsP2
760.21
Yellow
Formula weight
Colour
Crystal size (mm)
796.67
Orange
Orange
Orange
0.05ꢅ0.19ꢅ0.21 0.03ꢅ0.10ꢅ0.15
0.10ꢅ0.22ꢅ0.32 0.03ꢅ0.18ꢅ0.35 0.10ꢅ0.28ꢅ0.42 0.11ꢅ0.22ꢅ0.26
˚
a (A)
9.6697(6)
10.5947(6)
18.2349(11)
95.930(2)
90.070(2)
105.058(2)
1793.56(19)
Triclinic
12.0507(12)
12.5536(12)
23.919(2)
95.758(2)
100.706(2)
112.778(2)
3218.4(5)
Triclinic
19.1828(7)
19.4869(7)
20.4310(7)
12.0713(3)
19.6922(5)
25.2746(2)
18.9525(12)
20.7398(16)
18.0663(10)
10.8566(7)
12.0657(8)
16.3466(11)
109.467(2)
96.154(2)
108.176(2)
1864.1(2)
Triclinic
˚
b (A)
˚
c (A)
a (8)
b (8)
g (8)
V (A )
System
115.486(2)
116.034(5)
3
˚
6894.2(4)
Monoclinic
P21/c
6008.0(3)
Orthorhombic
Pbca
6380.8(7)
Monoclinic
P21/c
¯
P1
¯
P1
¯
P1
Space group
Z
2
4
8
8
8
2
Total data
Unique data
Rint
R (F2ꢀ2s(F2))
Rw (all data)
16 134
8364
27 960
14 360
0.0553
0.0474
0.1084
49 981
12 140
0.0310
0.0386
0.0942
44 465
5912
55 713
15 362
0.0482
0.0348
0.0783
13 558
6537
0.0223
0.0261
0.0532
0.0336
0.0471
0.0985
0.0149
0.0455
0.1196
2.4.5. [OsCl(h6-cym)S,S?-Ph2P(S)NP(S)Ph2] (5)
To a solution of [Os(h6-cym)Cl2]2 (0.025 g, 0.031
mmol) in THF (10 ml) was added K{Ph2P(S)}2N (0.033
g, 0.068 mmol) as a solid and the reaction stirred at
room temperature for 2 h. The solvent was removed
under vacuum and the yellow residue extracted into
CHCl3 (2 ml). The extract was filtered through Celite to
remove insoluble material before addition of 60:80
petroleum (10 ml) ether gave 5 as an orange micro-
crystalline solid. Yield: 0.042 g, 76%. IR: 1198, 1173
1a undergoes smooth isomerisation to afford the
cationic complex 1b containing an OsÃPÃNÃP chelate
ring. Reaction of [Os(h6-cym)Cl2]2 with K{Ph2P(E)}2N
(EꢁS; EꢁSe) at room temperature, in THF solution,
affords the monomeric osmium(II) complexes 5 and 6.
/
/
/
/
/
Analytical and selected spectroscopic data for 1aꢃ
/6 are
presented in Table 1.
The 31P{1H}-NMR data for 1aꢃ
/
6 are especially
diagnostic. Hence for compounds 1a and 2, the 31P
resonances are shifted downfield upon complexation
with respect to the free ligands [dppa d (P) 43.1 ppm;
n(PN); 572 n(PS) cmꢀ1
.
2
Compound 6 could also be prepared in a similar
manner. Yield: 0.050 g, 89%. IR: 1203, 1172 n(PN); 542
HL d (P) 27.8, 25.2 ppm, J(PP) 59 Hz (in CDCl3)] [8].
For 1a, two doublets at 25.6 and 23.9 ppm [2J(PP) 22
Hz] imply two dissimilar phosphorus environments (one
P-coordinated and the other noncoordinated) and this
is further supported by single crystal X-ray studies (see
below). Monodentate behaviour of this type has also
been observed with Ph2PN(H)C6H4PPh2 [30] where
n(PSe) cmꢀ1
.
3. Results and discussion
The dimeric complex [Os(h6-cym)Cl2]2 reacts with
two equivalents of HN(PPh2)2 (dppa) or Ph2PN(H)P-
(O)Ph2 (HL) in THF solution to form the monomeric
complexes, 1a and 2, respectively (Scheme 1) as orange,
air stable solids. For 2, this general bridge cleavage
procedure has successfully been used in our laboratories
for the preparation of various metal complexes contain-
ing HL [8,29]. Compound 2 can also be used for the
preparation of P,O-chelate complexes. Hence either
chloride abstraction with Ag[BF4] or, treatment with
tBuOK, affords the cationic and neutral complexes, 3
and 4, respectively (Scheme 1). In the latter case,
deprotonation yields an anionic chelating P,O-
[Ph2PNP(O)Ph2]ꢀ ligand. Independently 3 can be pre-
exclusively only the Ph2PN(H)Ã
/
centre participates in
metal complexation. In contrast 2 shows two closely
spaced resonances at d(P) 20.6 and 20.3 ppm which,
upon P,O-chelation as seen for both 3 and 4, signifi-
cantly move downfield as a consequence of five-mem-
bered chelate ring formation. The 31P{1H}-NMR data
for 5 and 6 are consistent with E,E?-coordination, and
in the latter case, a J(PSe) coupling of 558 Hz was
observed and is similar to previously reported examples
[17]. The 1H-NMR data for 1aꢃ
6 are broadly as
/
expected and show marginal variation in the position
of the h6-cym resonances as a consequence of varying
the ligands/different ligating modes adopted. Two sets
of doublets are clearly observed for the C6H4 protons of
the arene ring for 1a, 2, 5 and 6 whereas for 3 (and 4) all
pared by protonation of 4 with HBF4×
/
OEt2. By contrast

J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ
/93
89
Scheme 1. Preparation of compounds 1aꢃ
K{Ph2P(S)}2N or K{Ph2P(Se)}2N, THF.
/
6. (i) dppa or HL, THF, (ii) NEt3 (for 1b) or Ag[BF4], CH2Cl2, (iii) t BuOK, CH3OH, (iv) HBF4×
/OEt2, (v)
four aromatic Hs are unique. This presumably arises
from the three different ligands about the Os(II) centre
accounting for the four unique C6H4 environments.
Other characterising data are given in Table 1 and
Section 2.
complex (in 1a). The solvent forms short CÃ
/
HÁ Á ÁClcoord
˚
contacts to Cl(1) and Cl(2) [H(35)Á Á ÁCl(1) 2.683 A,
˚
H(35)Á Á ÁCl(2) 2.785 A] in contrast to NÃHÁ Á ÁClcoord
/
˚
˚
contacts [H(1)Á Á ÁCl(1) 2.931 A, H(1)Á Á ÁCl(2) 2.790 A,
˚
H(1)Á Á ÁCl(3?) 2.793 A] which are best described as very
Crystallographic studies (Tables 2 and 3) reveal
weak H-bonds. In 2 there is also an NÃ
/
HÁ Á ÁClcoord
structures for 1aꢃ6 that are very much in keeping with
/
˚
intramolecular H-bond [H(1)Á Á ÁCl(2) 2.479 A (molecule
simple predictions, with overall pseudo tetrahedral
‘piano-stool’ geometries. A comparison of 1a and 2 is
noteworthy here. Both compounds comprise an h6-
cymene, two chlorides and an h1-P-bound phosphi-
˚
I), H(2A)Á Á ÁCl(3) 2.675 A (molecule II)].
The X-ray structure of 3 (Fig. 3, Table 3) shows that
the osmium(II) centre is bound by a chelating P,O-
Ph2PNHP(O)Ph2, an h6-cymene and a chloride ligand.
In molecule I the OsP2O substituents are essentially
no(amine) ligand (Figs. 1 and 2). The OsÃ
OsÃCarene bond lengths are similar for both compounds.
The P(1)ÃN(1) distances [1.674(2) in 1a; 1.689(6)
(molecule I) and 1.692(6) A (molecule II) in 2] are
comparable whilst the N(1)ÃP(2) bond length in 1a
[1.711(2) A] is longer than in 2 [1.665(6) (molecule I) and
/
Cl, OsÃ/P and
/
˚
˚
planar to within 0.019 A with N(1) 0.190 A out of this
plane. An envelope conformation is observed as indi-
cated by a hinge angle of 12.88 between the OsP2O/P2N
planes. In molecule II the OsP2O substituents are
/
˚
/
˚
˚
essentially planar to within 0.022 A with P(3) lying
˚
1.663(6) A (molecule II)]. Furthermore the PÃ
/
NÃ/P
furthest out of this plane. Within the p-cymene ring the
Me and iPr groups both show distortions. Hence C(7) is
angle in 1a [124.71(14)8] is contracted with respect to
that found in 2 [132.0(4) (molecule I) and 127.1(4)8
˚
bent 0.049 A towards, and C(8) 0.258 A away, from Os
˚
(molecule II)]. The short PÄ/O distance compares well
˚
˚
(molecule I) and C(41) 0.185 A/C(42) 0.076 A away
from Os (molecule II). There is also a series of
intermolecular hydrogen bonds between molecules I
and II, a methanol solvate molecule and one of the
with that of HL [8] and known metal complexes in
which the phosphoryl group is non-coordinating [8,29].
Within the p-cymene ring, C(7) and C(8) are 0.003 and
˚
0.022 A out of the arene C6 mean plane and bent away
from Os (for 1a). For 2, C(7) [and C(41)] are out of the
two BF4ꢀ counterions [N(1)Á Á ÁF(8) 2.917, H(1)Á Á ÁF(8)
˚
˚
C(40)] mean planes by 0.020 A
2.10(2) A, N(1)Ã
/
H(1)Á Á ÁF(8) 168(6)8; N(2)Á Á ÁO(3)
˚
/
C(1)ꢀ
/
C(6) [C(35)ꢀ
/
˚
(0.068 A) towards Os. C(8) is bent 0.038 A away from
˚
2.821(8), H(2)Á Á ÁO(3) 1.98(2) A, N(2)Ã
173(6)8; O(3)Á Á ÁF(6) 2.840(12), H(3)Á Á ÁF(6) 2.03(5) A,
O(3)ÃH(3)Á Á ÁF(6) 159(12)8].
H(2)Á Á ÁO(3)
˚
˚
Os in molecule I (0.011 A away from Os in molecule II).
There is also one molecule of CHCl3 per osmium
/

90
J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ
/93
Table 3
˚
Selected bond lengths (A) and angles (8) for 1aꢃ6
/
a
a
a
1a
2
(EꢁO)
3
(EꢁO)
4 (EꢁO)
5
(EꢁS)
6 (EꢁSe)
Bond lengths
Os(1)ÃCl(1)
Os(1)ÃCl(2)
Os(1)ÃP(1)
Os(1)ÃE(1)
Os(1)ÃE(2)
E(1)ÃP
2.4199(7)
2.4213(7)
2.3432(8)
2.414(2) [2.423(2)]
2.428(2) [2.426(2)]
2.350(2) [2.334(2)]
2.3814(16) [2.3901(18)]
2.4136(16)
2.4232(12) [2.4172(13)]
2.4168(16)
2.3309(15) [2.3041(16)]
2.136(4) [2.141(4)]
2.3432(17)
2.153(4)
2.4321(14) [2.4463(13)]
2.4398(12) [2.4407(12)]
2.0305(17) [2.0283(17)]
2.0191(17) [2.0229(17)]
1.597(4) [1.599(4)]
2.5345(7)
2.5582(6)
2.1843(19)
2.1831(17)
1.601(5)
1.596(5)
1.674
1.473(5) [1.485(6)]
1.519(4) [1.508(4)]
1.524(5)
E(2)ÃP(2)
P(1)ÃN(1)
N(1)ÃP(2)
Os(1)ÃCcentroid
1.674(2)
1.711(2)
1.700
1.689(6) [1.692(6)]
1.665(6) [1.663(6)]
1.692 [1.692]
1.715(4) [1.697(5)]
1.648(5) [1.646(5)]
1.707 [1.709]
1.637(6)
1.586(5)
1.690
1.600(4) [1.600(4)]
1.677 [1.680]
Bond angles
Cl(1)ÃOs(1)ÃCl(2)
Cl(1)ÃOs(1)ÃP(1)
Cl(2)ÃOs(1)ÃP(1)
O(1)ÃOs(1)ÃP(1)
O(1)ÃOs(1)ÃCl(1)
Os(1)ÃP(1)ÃN(1)
N(1)ÃP(2)ÃO(1)
P(2)ÃO(1)ÃOs(1)
Cl(1)ÃOs(1)ÃE(1)
Cl(1)ÃOs(1)ÃE(2)
E(1)ÃOs(1)ÃE(2)
Os(1)ÃE(1)ÃP(1)
Os(1)ÃE(2)ÃP(2)
E(1)ÃP(1)ÃN(1)
E(2)ÃP(2)ÃN(1)
P(1)ÃN(1)ÃP(2)
85.02(3)
87.05(3)
85.38(3)
85.60(7) [84.59(7)]
86.71(7) [84.50(7)]
84.53(7) [86.90(7)]
85.34(6) [86.15(6)]
89.45(6)
83.71(11) [83.26(12)]
82.44(12) [81.55(14)]
103.76(17) [105.45(19)]
107.8(2) [108.0(3)]
81.21(12)
84.00(12)
109.01(19)
114.8(3)
113.59(9)
110.9(2) [110.3(2)]
115.8(3) [111.9(3)]
123.4(2) [123.4(2)]
118.4(2)
85.39(5) [81.19(4)]
79.79(4) [83.06(4)]
91.54(4) [87.71(4)]
83.10(5)
80.56(4)
85.73(2)
101.16(5)
100.99(5)
117.7(2)
116.5(2)
131.6(3)
110.56(6) [108.03(6)]
105.43(6) [103.25(6)]
117.98(16) [118.54(15)]
117.27(15) [116.43(15)]
126.5(3) [127.7(3)]
124.71(14)
132.0(4) [127.1(4)]
120.0(3) [119.8(3)]
114.1(3)
a
Two molecules in the asymmetric unit.
Fig. 2. The molecular structure of 2 (all CÃ
/
H atoms omitted for
Fig. 1. The molecular structure of 1a (all CÃ
/H atoms omitted for
clarity; two similar molecules in the asymmetric unit).
clarity, CHCl3 solvent molecule not shown).
The OsÃ
/
PÃ
/
NÃ
/
PÃ
/
O ring conformation in 4 is planar to
The X-ray structure of 4 (Fig. 4, Table 3) reveals the
osmium(II) centre is bound by a chelating, anionic
[Ph2PNP(O)Ph2]ꢀ, a chloride and an h6-cymene ligand.
˚
within 0.028 A with N lying 0.219 A out of this plane.
˚
The OsP2O versus P2N hinge angle is 14.98 and the ring

J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ
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91
Fig. 3. The structure of 3 (all CÃ
H atoms and the non H-bonded BF4ꢀ anion omitted for clarity).
/
Both {Ph2P(S)}2Nꢀ and {Ph2P(Se)}2Nꢀ act as
chelating ligands through their respective chalcogens.
˚
S [2.4321(14) and 2.4398(12) A for molecule I;
The OsÃ
/
˚
2.4463(13) and 2.4407(12) A for molecule II] and OsÃ
/
Se
˚
[2.5345(7) and 2.5582(6) A] distances in 5 and 6 are
comparable to those recently described by Leung et al.
for a series of six-coordinate Os(VI) complexes [23,24].
For 5 and 6 (Figs. 5 and 6, Table 3) the conformation of
the OsÃ
/
EÃ
/
PÃ
/
NÃ
/
PÃ
/
E rings are best described as ‘‘boat-
S
like’’. The P2S2 portion is non-planar and the SÃ
/
PÃPÃ
/
/
torsion angle is 258 (molecule I) and 188 (molecule II). In
˚
6, the Se2P2 fragment is planar to within 0.017 A with N
˚
lying 0.356 A out of this plane. The OsSe2 versus Se2P2
hinge angle is 67.68 and Se2P2 versus P2N is 338. Within
the metallacyles the EÃ
/
P/NÃ
/
P distances are longer/
S or Se) and
shorter than in free HN{P(E)Ph2}2 (Eꢁ
/
Fig. 4. The molecular structure of 4 (all CÃ
/H atoms omitted for
clarity).
adopts an envelope conformation. The C(7) group is
˚
0.072 A out of the p-cymene C6 mean plane towards Os
˚
and C(8) is 0.050 A in the same direction. There are no
significant inter/intramolecular interactions.
A brief comparison of the OsP2NO metallacycles is
especially noteworthy. In 3, the PÃ
/
N, NÃ
/
P and PÃ
/
O
˚
distances are 1.715(4), 1.648(5) and 1.519(4) A for
˚
molecule I [1.697(7), 1.648(5) and 1.508(4) A for
molecule II], respectively and similar to those in the
free ligand Ph2PNHP(O)Ph2 [8]. Within the PÃ
/
NÃ
/
PÃ
/
O
backbone of [Ph2PNP(O)Ph2]ꢀ in 4 there is a significant
˚
N bonds [1.637(6) and 1.586(5) A]
shortening of the PÃ
/
˚
O bond [1.524(5) A] as
and a small lengthening of the PÃ
/
a consequence of deprotonation. Compounds 3 and 4
represent rare examples of crystallographically charac-
terised osmium(II) arene complexes containing O/P/Cl
Fig. 5. The molecular structure of 5 (all CÃ
/
H atoms omitted for
donor atoms [31ꢃ33].
/
clarity; two similar molecules in the asymmetric unit).

92
J. Parr et al. / Journal of Organometallic Chemistry 664 (2002) 85ꢃ93
/
Acknowledgements
The authors thank Loughborough University for
support and the EPSRC National Mass Spectrometry
Service Centre at Swansea.
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˚
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