Ruthenium-assisted insertion of isothiocyanates into the silicon-sulfur bond: A comparative study on the reactivity of the S-Si and S-H bonds in CpRu(PPh3)2SX (X = H, SiiPr3) complexes

Article abstract of DOI:10.1021/om000497l

CpRu(PPh₃)₂SSiⁱPr₃ (1) and CpRu(PPh₃)₂SH (2) reacted with phenyl, p-tolyl, and 1-naphthyl isothiocyanates, as well as with 1,4-phenylene diisothiocyanate, to give the corresponding k²S,S-dithiocarbamato complexes, CpRu(PPh₃)S₂CNR¹R² (R¹ = SiⁱPr₃, R² = Ph (3a), p-Tol (3b), 1-Naphth (3c); R¹ = H, R² = Ph (3d), 1-Naphth (3e)) and 1,4-[CpRu(PPh₃)S₂CNR]₂C₆H ₄ (R = SiⁱPr₃ (4a), H (4b)), the result of insertion of the isothiocyanates into the S-Si and S-H bonds, respectively. The reactions of 1 proceed via precoordination of the isothiocyanates to the ruthenium atom, followed by the formation of N-silyl k²S,S-dithiocarbamates. The reactions of 2, at least in part, involve direct nucleophilic addition of the S-H bond to the isothiocyanates via k¹S-dithiocarbamato intermediates. Accordingly, CpRu(dppe)SSiⁱPr₃, where ligand exchange does not occur, did not react, but CpRu(dppe)SH reacted with phenyl and 1-naphthyl isothiocyanate to give the corresponding k¹S-dithiocarbamato complexes, CpRu(dppe)SC(S)NHR (R = Ph (9a), 1-Naphth (9b)), the reaction with 1-naphthyl isothiocyanate being reversible. The crystal structures of 3c and 4a have been determined by X-ray diffraction.

Full text of DOI:10.1021/om000497l

Organometallics 2001, 20, 35-41
35
Ru th en iu m -Assisted In ser tion of Isoth iocya n a tes in to th e
Silicon -Su lfu r Bon d : A Com p a r a tive Stu d y on th e
Rea ctivity of th e S-Si a n d S-H Bon d s in Cp Ru (P P h 3)2SX
(X ) H, SiiP r 3) Com p lexes†
Istva´n Kova´cs, Anne-Marie Lebuis, and Alan Shaver*
Department of Chemistry, McGill University, 801 Sherbrooke Street West,
Montreal, Quebec H3A 2K6, Canada
Received J une 13, 2000
CpRu(PPh3)2SSiiPr3 (1) and CpRu(PPh3)2SH (2) reacted with phenyl, p-tolyl, and 1-naph-
thyl isothiocyanates, as well as with 1,4-phenylene diisothiocyanate, to give the corresponding
κ2S,S-dithiocarbamato complexes, CpRu(PPh3)S2CNR1R2 (R1 ) SiiPr3, R2 ) Ph (3a ), p-Tol
(3b), 1-Naphth (3c); R1 ) H, R2 ) Ph (3d ), 1-Naphth (3e)) and 1,4-[CpRu(PPh3)S2CNR]2C6H4
(R ) SiiPr3 (4a ), H (4b)), the result of insertion of the isothiocyanates into the S-Si and
S-H bonds, respectively. The reactions of 1 proceed via precoordination of the isothiocyanates
to the ruthenium atom, followed by the formation of N-silyl κ2S,S-dithiocarbamates. The
reactions of 2, at least in part, involve direct nucleophilic addition of the S-H bond to the
isothiocyanates via κ1S-dithiocarbamato intermediates. Accordingly, CpRu(dppe)SSiiPr3,
where ligand exchange does not occur, did not react, but CpRu(dppe)SH reacted with phenyl
and 1-naphthyl isothiocyanate to give the corresponding κ1S-dithiocarbamato complexes,
CpRu(dppe)SC(S)NHR (R ) Ph (9a ), 1-Naphth (9b)), the reaction with 1-naphthyl isothio-
cyanate being reversible. The crystal structures of 3c and 4a have been determined by X-ray
diffraction.
In tr od u ction
due to their instability. The only direct comparative
study, of the reactions of CpRu(PPh3)2SSiiPr3 (1) and
its hydrosulfido congener CpRu(PPh3)2SH (2) with SO2
and PhNSO, gave contrasting results.3 Complex 1
readily afforded the ligand-substitution product CpRu-
(PPh3)(SO2)SSiiPr3 and subsequently the insertion prod-
uct CpRu(PPh3)2SS(O)OSiiPr3. While 2 also reacted with
SO2, no product could be identified. On the other hand,
the S-H bond of 2 readily added to PhNSO to give
CpRu(PPh3)2SS(O)NHPh, but the silicon-sulfur bond
of 1 remained indifferent (1 underwent reversible ligand
substitution to give CpRu(PPh3)(PhNSO)SSiiPr3 in low
yield).
The reaction of sulfhydryl complexes, M-SH, to give
hydrothiosulfito species, M-SS(O)OH, has been sug-
gested as a possible key step in the homogeneously
catalyzed Claus reaction1 and SO2 hydrogenation.2 The
insertion of SO2 into the silicon-sulfur bond of ruthe-
nium silanethiolato complexes of the type CpRuL2SSi-
iPr3 to give O-silyl thiosulfito complexes, CpRuL2SS-
(O)OSiiPr3, has been reported recently.3 Thus, the
-SSiR3 function in some silanethiolates and the -SH
function in some hydrosulfides seemed to have analo-
gous chemistry. Reports on the deprotonation of Cp2Ti-
(SH)24 and analogous desilation of [Ru(N)Me3(SSiMe3)]-,5
which are believed to take place via common M-S- type
intermediates, support this assumption. However, none
of these analogies were confirmed unambiguously, as
no products of the type M-SS(O)OH or M-S- were
detected and no O-silyl thiosulfito complex was isolated
The contrasting behavior of the -SSiiPr3 function of
1 toward SO2 and PhNSO, as well as the problem of
the analogy between silanethiolato and sulfhydryl com-
plexes, prompted us to study the reactions of CpRu-
(PPh3)2SSiiPr3 and CpRu(PPh3)2SH with heterocumu-
lenes. Here we give an account of their reactions with
aryl isothiocyanates and report the crystal and molec-
ular structures of CpRu(PPh3)S2CN(SiiPr3)Naphth (3c)
and 1,4-[CpRu(PPh3)S2CN(SiiPr3)]2C6H4 (4a ).
* Corresponding author. Fax: (514) 398-3797. E-mail: shaver@
chemistry.mcgill.ca.
† Parts of this work have been presented at the (a) 218th ACS
National Meeting, New Orleans, LA, Aug 22-26, 1999, Abstract INOR
208 (Abstr. Pap. Am. Chem. Soc. 1999, 218, 208-INOR) and (b) 82nd
CSC Conference and Exhibition, Toronto, ON, Canada, May 30-J une
2, 1999, Abstract 918.
Resu lts
(1) Shaver, A.; El-khateeb, M.; Lebuis, A.-M. Angew. Chem., Int. Ed.
Engl. 1996, 35, 2362.
R ea ct ion of Cp R u (P P h 3)2SSiiP r 3 (1) w it h Ar yl
Isoth iocyan ates. CpRu(PPh3)2SSiiPr3 (1) reacted readily
with equimolar amounts of RNCS (R ) Ph, p-Tol,
1-Naphth) in THF at room temperature to give the
corresponding N-silyl κ2S,S-dithiocarbamato complexes
in accordance with eq 1. The new complexes CpRu-
(PPh3)S2CN(SiiPr3)R (R ) Ph (3a ), p-Tol (3b), 1-Naphth
(2) (a) Kubas, G. J .; Ryan, R. R. J . Am. Chem. Soc. 1985, 107, 6138.
(b) Kubas, G. J .; Ryan, R. R. Polyhedron 1986, 5, 473.
(3) Kovacs, I.; Shaver, A. J . Organomet. Chem. 2000, 596, 193.
(4) (a) Ruffing, C. J .; Rauchfuss, T. B. Organometallics 1985, 4, 524.
(b) Lundmark, P. J .; Kubas, G. J .; Scott, B. L. Organometallics 1996,
15, 3631. (c) Casado, M. A.; Ciriano, M. A.; Edwards, A. J .; Lahoz, F.
J .; Oro, L. A.; Perez-Torrente, J . J . Organometallics 1999, 18, 3025.
(5) Liang, H.-C.; Shapley, P. A. Organometallics 1996, 15, 1331.
10.1021/om000497l CCC: $20.00 © 2001 American Chemical Society
Publication on Web 12/07/2000

36 Organometallics, Vol. 20, No. 1, 2001
Kova´cs et al.
CpRu(PPh3)2SSiiPr3 + RNCS f
1
CpRu(PPh3)S2CN(SiiPr3)R + PPh3 (1)
3a -c
(3c)) were isolated by crystallization as air and ther-
mally stable, yellow to orange crystals in good yield.
When 1 was treated with PhNCS in benzene-d6, 1H and
31P NMR spectroscopic monitoring indicated quantita-
tive formation of 3a and free PPh3 in 1:1 molar ratio
upon mixing. However, when this experiment was
repeated with CpRu(dppe)SSiiPr3, the starting materi-
als remained unchanged at room temperature for at
least one week.
Complexes 3a -c were characterized by elemental
analysis and multinuclear NMR spectroscopy, and the
results are in complete agreement with the suggested
structures. In particular, the 1H, 13C, and 31P NMR
spectra for all three complexes exhibited Cp proton (δ
F igu r e 1. ORTEP drawing of CpRu(PPh3)S2CN(SiiPr3)-
Naphth (3c). Thermal ellipsoids are drawn at the 40%
probability level. Hydrogen atoms are omitted for clarity.
Selected bond distances (Å) and angles (deg) are as fol-
lows: Ru-S(1), 2.387(3); Ru-S(2), 2.394(2); Ru-P, 2.269-
(2); S(1)-C(33), 1.690(6); S(2)-C(33), 1.708(6); N-C(33),
1.377(7); Si-N, 1.824(5); N-C(34), 1.505(9); S(1)-Ru-S(2),
71.69(8); S(1)-Ru-P, 95.02(9); S(2)-Ru-P, 92.56(9); Ru-
S(1)-C(33), 88.8(2); Ru-S(2)-C(33), 88.1(2); S(1)-C(33)-
S(2), 111.0(3); S(1)-C(33)-N, 125.8(4); S(2)-C(33)-N,
123.2(5); C(33)-N-Si, 122.5(4); C(33)-N-C(34), 115.9(5);
Si-N-C(34), 121.0(4).
i
4.4) and carbon (ca. δ 77), S2CN carbon (ca. δ 228), Pr
carbon (ca. δ 14 (CH), 19 (CH3)), and phosphorus
resonances (ca. δ 54) at nearly identical positions,
suggesting similar structures and negligible substituent
effects. The Cp and PPh3 resonances agree well with
the literature data for CpRu(PPh3)S2CNMe2.6 Integra-
tion of the proton spectra indicated the presence of only
one PPh3 ligand in each molecule. Similarly, the S2CN
carbon atoms resonated as a doublet, suggesting P-C
coupling with one phosphine only. Curiously, no such
carbon resonances were detected for η5-C5R5RuLS2-
CNEt2 (R ) H, Me; L ) PiPr2Me, PEt3) type κ2S,S-
dithiocarbamato complexes, which was attributed to the
effect of the quadrupolar 14N nucleus.7 The 1H NMR
spectrum of 3c exhibited two sets of methyl doublets of
equal intensity, which were temperature invariant in
the range 20-100 °C, while only one methyl doublet was
observed for 3a ,b. This difference is probably due to a
strong steric interaction between the bulky SiiPr3 and
naphthyl groups that hinders rotation in the ligand of
3c.
The crystal structure of 3c was determined by X-ray
diffraction (Figure 1) and verified the presence of the
N-Si bond in the dithiocarbamato group. Most of the
bond lengths and angles in the CpRu(PPh3)S2CN moiety
show negligible deviation from those of CpRu(PPh3)S2-
CNMe2 in both of its polymorphic forms.6,8 The geometry
around the nitrogen atom is nearly planar as the N-Si
bond subtends an angle of only 9° with the plane defined
by the atoms C(33), C(34), and N.
of 4a exhibited a singlet resonance at δ54.7 and one set
of iPr, Cp, and PPh3 proton and carbon resonances were
observed in its 1H and 13C NMR spectra at expected
positions. These spectroscopic features are very similar
to those of the mononuclear complexes 3a ,b and sug-
gested equivalent CpRu(PPh3)S2CN(SiiPr3) units in a
symmetric molecule.
The crystal structure of 4a was determined by X-ray
diffraction and is shown in Figure 2. The structural
analysis unambiguously established that each -NCS
function of 1,4-phenylene diisothiocyanate inserted into
the S-Si bond of two molecules of 1 to form a phenylene-
bridged, dimeric N-silyl κ2S,S-dithiocarbamato struc-
ture. Complex 4a has a center of symmetry, consistent
with NMR observations. The bond lengths and angles
in the CpRu(PPh3)S2CN(SiiPr3) moieties are nearly
identical with those in 3c. It is noteworthy that the
phenylene ring is eclipsed with one phenyl ring of each
PPh3 ligand and the phenyl planes are parallel to each
other. On the macromolecular level, 4a is packed to form
parallel layers separated by hexane molecules. The
hexane molecules are crystallographically disordered
and do not form a stoichiometric ratio with the com-
plex: 1.4 hexanes were calculated to be present in the
unit cell, which agrees well with the value of 1.6
obtained from analytical data.
The reaction of 1,4-phenylene diisothiocyanate with
2 equiv of 1 in THF at room temperature gave 1,4-
[CpRu(PPh3)S2CN(SiiPr3)]2C6H4 (4a ) along with 2 equiv
of free PPh3 as shown in eq 2. The 31P NMR spectrum
Reaction of CpRu (P P h 3)2SH (2) with Ar yl Isoth io-
cya n a t es. CpRu(PPh3)2SH (2), treated with RNCS
(R ) Ph, 1-Naphth) in benzene at room temperature,
gave ultimately the corresponding κ2S,S-dithiocarba-
mato complexes, CpRu(PPh3)S2CNHR (R ) Ph (3d ),
1-Naphth (3e)), as shown in eq 3. Complex 3e was
2 CpRu(PPh3)2SSiiPr3 + 1,4-(SCN)2C6H4 f
1a
1,4-[CpRu(PPh3)S2CN(SiiPr3)]2C6H4 + 2 PPh3 (2)
4a
CpRu(PPh3)2SH + RNCS f
(6) McCubbin, Q. J .; Stoddart, F. J .; Welton, T.; White, A. J . P.;
Williams, D. J . Inorg. Chem. 1998, 37, 3753.
(7) Coto, A.; Tenorio, M. J .; Puerta, M. C.; Valerga, P. Organome-
tallics 1998, 17, 4392.
2
CpRu(PPh3)S2CNHR + PPh3 (3)
3d ,e
(8) Cordes, A. W.; Draganjac, M. Acta Crystallogr. 1988, C44, 363.

Ruthenium-Assisted Insertion of Isothiocyanates
Organometallics, Vol. 20, No. 1, 2001 37
The reaction of 1,4-phenylene diisothiocyanate with
2 equiv of 2 ultimately gave the anticipated dinuclear
κ2S,S-dithiocarbamato complex 1,4-[CpRu(PPh3)S2CNH]2-
C6H4 (4b) in accordance with eq 4 as orange microcrys-
tals. Consistent with its symmetrical structure and the
κ2S,S-coordination mode of dithiocarbamato functions
a singlet phosphorus resonance was observed at δ 54.1.
2 CpRu(PPh3)2SH + 1,4-(SCN)2C6H4 f
2
1,4-[CpRu(PPh3)S2CNH]2C6H4 + 2 PPh3 (4)
4b
When this reaction was performed in benzene-d6 and
1
monitored by H and 31P NMR spectroscopy, a complex
reaction sequence was detected because the -NCS
groups of 1,4-phenylene diisothiocyanate react at dif-
ferent reaction rates. When it was applied in a 3-fold
excess, 2 was immediately consumed and a mono-κ1S-
dithiocarbamato intermediate, 4-[CpRu(PPh3)2SC(S)-
NH]C6H4NCS (6), formed almost exclusively. Complex
6 transformed over several hours to give 4-[CpRu-
(PPh3)S2CNH]C6H4NCS (7) as the thermodynamically
stable product. Thus, the -NCS function in 6 has a
significantly lower reactivity than that of 1,4-phenylene
diisothiocyanate, probably due to electronic effects of the
coordinated ruthenium center. When the ratio was
stoichiometric or there was an excess of 2, a mixture of
6 and 7 formed immediately, followed by the formation
of 4-[CpRu(PPh3)2SC(S)NH]C6H4[NHCS2Ru(PPh3)Cp]
(8) and 4b. Although the ratio of all these species
constantly changed as the reaction progressed, the
amount of 8 always remained very low. No evidence for
the bis-κ1S-dithiocarbamato intermediate 1,4-[CpRu-
(PPh3)2SC(S)NH]C6H4[NHC(S)SRu(PPh3)2Cp] was de-
tected. As in previous experiments, the NH and aro-
matic ortho proton resonances for all complexes con-
taining κ2S,S-coordinated dithiocarbamato ligand(s),
e.g., 7, 8, and 4b, shifted to higher fields while the
reaction was in progress. Characteristic NMR data for
complexes 4b and 6-8 are listed in Table 1.
F igu r e 2. ORTEP drawing of 1,4-[CpRu(PPh3)S2CN(Si-
iPr3)]2C6H4 (4a ). Thermal ellipsoids are drawn at the 40%
probability level. Hydrogen atoms are omitted for clarity.
Selected bond distances (Å) and angles (deg) are as fol-
lows: Ru-S(1), 2.381(2); Ru-P, 2.275(2); S(1)-C(31),
1.700(5); S(2)-C(31), 1.706(5); N-C(31), 1.376(6); Si-N,
1.794(7); N-C(28), 1.445(6); S(1)-Ru-P, 89.64(7); Ru-
S(1)-C(31), 89.1(2); Ru-S(2)-C(31), 88.6(2); S(1)-C(31)-
N, 124.7(4); S(2)-C(31)-N, 125.2(4); C(31)-N-Si, 124.0(3);
C(31)-N-C(28), 113.3(4); Si-N-C(28), 122.2(3).
isolated as air-stable, orange microcrystals, and 3d was
identified in solution. Their 1H and 31P NMR spectra
are practically identical with the corresponding reso-
nances for 3a -c, suggesting similar κ2S,S-dithiocarba-
mato structures. The S2CN carbon doublet for 3e was
detected at δ 217.4, about 10 ppm upfield from those
for 3a -c but close to that for CpRu(PPh3)S2CNMe2.6
The NH proton resonances for 3d ,e were observed at δ
7.43 and 7.82, respectively, as broad singlets.
Monitoring the reactions of 2 by 1H and 31P NMR
spectroscopy in benzene-d6 confirmed the quantitative
formation of a 1:1 mixture of 3d ,e and free PPh3. In
addition, the following observations were made. (1)
When the reagents were applied in a stoichiometric
ratio, both PhNCS and 1-NaphthNCS reacted at a
comparable rate (2 was consumed in about 1 h). (2) The
NH proton resonance and, to a lesser extent, the ortho
proton resonance(s) of NPh and NNaphth in 3d ,e shifted
upfield as the reactions progressed. The NH resonance
was first observed about 0.25 ppm downfield from its
final position, while the ortho proton resonances moved
only about 0.05 ppm upfield for both complexes. Once
the reactions were complete, these resonances did not
show any significant change in the temperature range
between 20 and 70 °C. (3) In the reaction of PhNCS with
2 a second, transient species was detected in addition
to 3d , which ultimately transformed into 3d . This minor
species was tentatively identified as the κ1S-dithiocar-
bamate CpRu(PPh3)2SC(S)NHPh (5) on the basis of its
phosphorus (δ 42.2), Cp proton (δ 4.78), and NH proton
(δ 9.21) resonances. Unlike the NH proton resonance
for 3d , that for 5 did not change its position during the
reaction, ruling out a κ1-κ2 equilibrium. The naphthyl
analogue, CpRu(PPh3)2SC(S)NHNaphth, was not de-
tected.
The transient appearance of κ1S-dithiocarbamato
intermediates 5, 6, and 8 in the above reactions sug-
gested that CpRu(dppe)SH might be reactive toward
isothiocyanates, in contrast with its silanethiolato ana-
logue. Indeed, reactions with RNCS (R ) Ph, 1-Naphth)
proceeded smoothly in benzene at room temperature to
give the corresponding κ1S-dithiocarbamato complexes,
CpRu(dppe)SC(S)NHR (R ) Ph (9a ), 1-Naphth (9b)), as
the sole products (eq 5) which were characterized by
their multinuclear NMR spectra. The 31P NMR spectra
CpRu(dppe)SH + RNCS 9
rt8
CpRu(dppe)SC(S)NHR (5)
9a ,b
exhibited singlet resonances at about δ 78, consistent
with the chelating coordination mode of dppe and
equivalent phosphorus environments. The 1H NMR
spectra exhibited singlet resonances attributable to the
NH proton at about δ 9.45, which did not change as the
reactions progressed. Spectroscopic monitoring also
showed that both reactions were considerably slower
than the corresponding reactions of 2, PhNCS being
consumed after 4 h, and 1-NaphthNCS reacted only

38 Organometallics, Vol. 20, No. 1, 2001
Ta ble 1. Ch a r a cter istic NMR Reson a n ces for Com p lexes 4b a n d 6-8
Kova´cs et al.
1H NMR
13C{1H} NMR
(δ, ppm)a
(δ, ppm)a
31P{1H} NMR
(δ, ppm)b
Cp
C6H4
NH
Cp
4-[CpRu(PPh3)2SC(S)NH]C6H4NCS (6)
4-[CpRu(PPh3)S2CNH]C6H4NCS (7)
4.76
6.48 (dt, J 1 ) 2 Hz, J 2 ) 9 Hz, 2H),
7.15 (dt, J 1 ) 2 Hz, J 2 ) 9 Hz, 2H)
6.35 (dt, J 1 ) 2 Hz, J 2 ) 9 Hz, 2H),
6.76 (dt, J 1 ) 2 Hz, J 2 ) 9 Hz, 2H)
9.07
83.1
42.3
4.42
7.32
76.5
54.1
4-[CpRu(PPh3)2SC(S)NH]C6H4-
[NHCS2Ru(PPh3)Cp] (8)
1,4-[CpRu(PPh3)S2CNH]2C6H4 (4b)
4.45,
4.75
4.43
∼7.35,
9.14
∼7.55
42.2,
54.1
54.1
6.92 (s, 4H)
76.5c
a
b
Recorded in benzene-d6 relative to TMS, unless noted otherwise. Recorded in benzene-d6 relative to 85% H3PO4. c Recorded in DMSO-
d6.
Sch em e 1
after 3 days. Surprisingly, when acceleration of the
latter reaction by moderate heating was attempted, the
formation of a 1:1 mixture of the starting materials was
observed instead. Upon standing at room temperature
for 3 days, 9b was nearly completely reformed, suggest-
ing an equilibrium that favors 9b at room temperature
(eq 6). Heating 9a in benzene-d6 partially decomposed
it, but no CpRu(dppe)SH was observed.
rt
CpRu(dppe)SH + 1-NaphthNCS y80 °Cz
CpRu(dppe)SC(S)NHNaphth (6)
9b
Discu ssion
Insertion of isothiocyanates into the silicon-sulfur
bond of a silanethiolato complex to generate N-silyl
κ2S,S-dithiocarbamato complexes (eqs 1, 2) has not been
reported until now. While numerous κ2S,S-dithiocarba-
mato complexes of various metals have been reported,
including relevant complexes of the type CpRu(PR3)-
S2CNR′2,6-9 the great majority of these were prepared
by reacting metal halides with robust N,N-dialkyl
dithiocarbamate anions, the latter being generated from
CS2 and dialkylamides. Silylated dithiocarbamato com-
plexes, however, are not known, and the reactions
described here are a novel method for the preparation
of κ2S,S-dithiocarbamates. The synthesis of dppe-
substituted κ1S-dithiocarbamato complexes 9a ,b is also
interesting from a preparative point of view since an
attempt to prepare analogous N,N-dialkyl dithiocarba-
mato complexes by the conventional method, reaction
of CpRu(dppe)Cl with [S2CNR2]-, failed and gave octa-
hedral (dppe)Ru(S2CNEt2)2 instead.9c Nevertheless, at
least one cyclopentadienyl κ1S-dithiocarbamato ruthe-
nium complex, CpRu(PEt3)2SC(S)NEt2, has been re-
ported recently.7
dinatively unsaturated species. It is reasonable to
assume that isothiocyanates coordinate to the ruthe-
nium atom via the CdS bond in a κ2 fashion. Precoor-
dination of CS2 has been suggested as the mechanism
whereby it inserts into the Ru-S bonds of the analogous
CpRu(PPh3)2SR (R ) alkyl, aryl, H) thiolato complexes
to give thioxanthato complexes.10,11 Coordination via the
CdNR bond can be ruled out since 1 is inert toward
CyNdCdNCy.12 Subsequently, the silanethiolato sulfur
may attack the activated -NCS carbon, followed by silyl
group transfer from sulfur to nitrogen. In any event,
both sulfur atoms remain permanently in the coordina-
tion sphere of the ruthenium atom and eventually form
the κ2S,S-dithiocarbamato structure. This scenario points
to a pivotal role of the metal atom in the insertion of
isothiocyanates into the S-Si bond of 1. When access
to ruthenium is blocked, as in CpRu(dppe)SSiiPr3, no
reaction occurs.
The mechanism outlined in Scheme 1 is markedly
different from that of the insertion of SO2.3 Although
SO2 can displace a PPh3 ligand and coordinate to the
ruthenium atom of 1 and it can also insert into the S-Si
bond of 1, the two reactions are neither concerted not
connected. It appears that nucleophilic attack by the
silanethiolato sulfur atom on the sulfur atom in SO2
takes place directly. The subsequent transfer of the silyl
group is probably facilitated by the formation of a strong
Si-O bond. Accordingly, such insertions readily take
The inertness of CpRu(dppe)SSiiPr3 and the observa-
tion that no κ1S-dithiocarbamato intermediates were
detected starting from 1 suggest a dissociative pathway
(Scheme 1), rather than direct nucleophilic addition of
the S-Si bond to isothiocyanates. It has been demon-
strated recently3 that 1 is extraordinarily susceptible
to ligand exchange with CO, phosphines, phosphites,
and SO2 due to the steric and electronic effects of the
-SSiiPr3 group, which facilitates dissociation of at least
one PPh3 ligand and stabilizes the resulting 16e coor-
(10) Shaver, A.; Plouffe, P.-Y.; Bird, P.; Livingstone, E. Inorg. Chem.
1990, 29, 1826.
(11) Complex 1 also reacted readily with CS2 to give a 1:1 mixture
of CpRu(PPh3)S2CSSiiPr3 and free PPh3.12 Interestingly, this compound
subsequently decomposed to CpRu(PPh3)S2CSRu(PPh3)2Cp10 and prob-
ably iPr3SiOH, suggesting partial deinsertion of CS2 and hydrolysis of
the S-Si bond.
(9) (a) Wilczewski, T.; Bochenska, M.; Biernat, J . F. J . Organomet.
Chem. 1981, 215, 87. (b) Reventos, L. B.; Alonso, A. G. J . Organomet.
Chem. 1986, 309, 179. (c) Alonso, A. G.; Reventos, L. B. J . Organomet.
Chem. 1988, 338, 249.
(12) Kovacs, I.; Shaver, A. Unpublished results.

Ruthenium-Assisted Insertion of Isothiocyanates
Organometallics, Vol. 20, No. 1, 2001 39
place with CpRu(dppe)SSiiPr3 and other ligand-substi-
tuted derivatives of 1, which are resistant to loss of
PPh3. On the other hand SO2 can also act as a ligand
and coordinate to ruthenium, but then it is not suscep-
tible to nucleophilic attack while in the coordination
sphere of the metal. The reactivity of PhNSO is inter-
mediate between that of SO2 and isothiocyanates: it can
coordinate to 1 in a manner similar to SO2, but it is
indifferent toward direct nucleophilic attack, as is
PhNCS.
Exp er im en ta l Section
All manipulations were carried out under an inert atmo-
sphere (N2 or Ar), using standard Schlenk technique and a
drybox. Solvents were dried and freshly distilled under
nitrogen prior to use. CpRu(PPh3)2SSiiPr3, CpRu(dppe)SSiiPr3,
CpRu(PPh3)2SH, and CpRu(dppe)SH were prepared according
to literature procedures.3 Phenyl-, p-tolyl-, and 1-naphthyl
isothiocyanate, as well as 1,4-phenylene diisothiocyanate were
purchased from Aldrich and were used as received. 1H, 13C-
{1H}, and 31P{1H} NMR measurements were performed on a
J EOL CPF 270 spectrometer. The 1H and 13C NMR spectra
were referenced to TMS and the 31P NMR spectra to 85% H3-
PO4. Elemental analyses were carried out by the Laboratoire
d’Analyse Elementaire at the University of Montreal.
Cp Ru (P P h 3)S2CN(SiiP r 3)P h (3a ). A solution of 1, freshly
prepared from CpRu(PPh3)2Cl (1.0 g, 1.37 mmol) in 50 mL of
THF-acetone as reported,3 was treated with phenyl isothio-
cyanate (0.19 g, 1.37 mmol) at room temperature. The red-
orange color of 1 changed to yellow-brown shortly after the
reagents were mixed. The reaction mixture was stirred
overnight. Then the solvent was removed under reduced
pressure, and the residue was redissolved in CH2Cl2. This
solution was filtered through Celite, concentrated under
reduced pressure, and layered with hexane. Cooling to -20
°C gave a lemon yellow, cotton-like crystalline material, which
was filtered and dried. Yield: 0.72 g (0.96 mmol, 70%). Anal.
Calcd for C39H46NPRuS2Si: C, 62.20; H, 6.16; N, 1.86. Found:
C, 62.04; H, 6.38; N, 1.92. 1H NMR (C6D6): δ 1.06 (d, J ) 7
Hz, 18H, CH3), 1.77 (sept, J ) 7 Hz, 3H, CH), 4.40 (s, 5H,
Cp), 7.05 (m, 14H, m,p-PPh+NPh), 7.66 (m, 6H, o-PPh). 13C-
{1H} NMR (C6D6): δ 13.7 (CH), 18.7 (CH3), 77.3 (d, J PC ) 3
Hz, Cp), 127.0 (p-NPh), 128.5 (o,m-NPh), 130.5 (p-PPh), 133.9
(d, J PC ) 11 Hz, o-PPh), 139.1 (d, J PC ) 38 Hz, ipso-PPh), 141.9
(ipso-NPh), 228.4 (d, J PC ) 5 Hz, S2CN); the m-PPh doublet
was covered by the solvent resonance but was clearly observed
in CDCl3 at 127.3 (J PC ) 9 Hz). 31P{1H} NMR (C6D6): δ 54.0.
Cp Ru (P P h 3)S2CN(SiiP r 3)Tol (3b). This material was
prepared similarly to 3a , using p-tolyl isothiocyanate (0.20 g,
1.37 mmol). Yellow microcrystals formed. Yield: 0.61 g (0.80
mmol, 58%). Anal. Calcd for C40H48NPRuS2Si: C, 62.63; H,
6.31; N, 1.83; S, 8.36. Found: C, 62.83; H, 6.46; N, 1.87; S,
8.80. 1H NMR (C6D6): δ 1.09 (d, J ) 7 Hz, 18H, CH3 (iPr)),
1.79 (sept, J ) 7 Hz, 3H, CH), 2.01 (s, 3H, CH3 (Tol)), 4.40 (s,
5H, Cp), 6.92 (“d”, J ) 8 Hz, 2H, Tol), 7.05 (m, 11H,
m,p-Ph+Tol), 7.66 (m, 6H, o-Ph). 13C{1H} NMR (C6D6): δ 13.7
(CH), 18.8 (CH3 (iPr)), 20.8 (CH3 (Tol)), 77.3 (d, J PC ) 2 Hz,
Cp), 128.5 (C-2,2′, Tol), 129.2 (C-3,3′, Tol), 130.2 (p-Ph), 133.9
(d, J PC ) 11 Hz, o-Ph), 136.6 (C-1, Tol), 139.2 (d, J PC ) 38 Hz,
ipso-Ph), 139.3 (C-4, Tol), 228.6 (d, J PC ) 5 Hz, S2CN); the
m-Ph doublet was hidden under the solvent resonances but
was clearly observed in CDCl3 at 127.3 (J PC ) 9 Hz). 31P{1H}
NMR (C6D6): δ 53.9.
Cp Ru (P P h 3)S2CN(SiiP r 3)Na p h th (3c). This complex was
prepared as 3a , using 1-naphthyl isothiocyanate (0.25 g, 1.37
mmol). Large, dark orange crystals formed from CH2Cl2-
hexane at room temperature. Yield: 0.61 g (0.76 mmol, 56%).
Anal. Calcd for C43H48NPRuS2Si: C, 64.31; H, 6.02; N, 1.74.
Found: C, 63.99; H, 5.85; N, 1.79. 1H NMR (C6D6): δ 1.02,
1.09 (both d, J ) 6 Hz, 9H each, CH3), 1.79 (sept, J ) 6 Hz,
3H, CH), 4.40 (s, 5H, Cp), 7.07 (m, 9H, m,p-Ph), 7.17, 7.35,
7.53 (all m, 2H, Naphth), 7.63 (m, 6H, o-Ph), 8.28 (“d”, 1H,
Naphth). 13C{1H} NMR (C6D6): δ 14.2 (CH), 19.2 (CH3), 77.5
(Cp), 124.9, 125.2, 125.7, 125.8, 132.4 (all Naphth), 133.8 (d,
J PC ) 11 Hz, o-Ph), 134.7, 139.1 (both Naphth), 139.4 (d,
J PC ) 39 Hz, ipso-Ph), 228.6 (d, J PC ) 8 Hz, S2CN); the m-Ph,
p-Ph, and three missing Naphth resonances were buried under
those of the solvent but were identified in CDCl3 at 127.3 (d,
J PC ) 9 Hz, m-Ph), 127.6, 127.9, 128.3 (all Naphth), and 128.5
(p-Ph). 31P{1H} NMR (C6D6): δ 53.7.
While the reactions of 1 with isothiocyanates are
unprecedented, those of 2 are not. CpNi(PBu3)SH13 and
[(CO)5WSH]- 14 react with PhNCS to give CpNi(PBu3)-
SC(S)NHPh and [(CO)5WSC(S)NHPh]-, respectively.
The latter ultimately transformed into the κ2S,S-dithio-
carbamato derivative [(CO)4WS2CNHPh]- via loss of
CO. Another interesting example is that of [Au(SH)2]-,
which gave the unusual mononuclear bis-κ1S-dithiocar-
bamato complex [PhNHC(S)SAuSC(S)NHPh]-.15 Al-
though the mechanism(s) of these reactions was not
studied in detail, it was suggested that direct nucleo-
philic addition of the S-H bond to the isothiocyanates
probably took place.14 It appears to be the most reason-
able explanation for the formation of κ1S-dithiocarba-
mato complexes 5, 6, and 9a ,b as well. Complexes 5 and
6 then spontaneously transformed into their thermo-
dynamically stable κ2S,S-dithiocarbamato derivatives
via loss of PPh3. Note, however, that 2 is substitution
labile,10 although to a lesser extent than 1,3 and ligand
exchange with isothiocyanates may be possible. Thus,
a mechanism analogous to that outlined in Scheme 1
cannot be excluded as a route to 3d ,e. This conclusion
is particularly relevant to the reaction of 2 with phenyl
and 1-naphthyl isothiocyanates (eq 3). The κ1S-dithio-
carbamato intermediate 5 was observed only as a minor
species even in early stages of the reaction, while the
naphthyl analogue could not be detected. Although no
quantitative information is available about the rate of
the κ1fκ2 transformation, spectroscopic monitoring sug-
gests that the conversion of κ1S-dithiocarbamato inter-
mediates is probably too slow to be the only pathway
leading to κ2S,S-dithiocarbamates. This assumption is
further supported by the much slower reactions of
CpRu(dppe)SH with the same substrates, which are
“pure” additions. Of particular importance here is the
1-naphthyl isothiocyanate derivative 9b, the only known
example for reversible formation of a κ1S-dithiocarba-
mato complex. It is reasonable to expect that 2 could
form the naphthyl analogue of 5 and that the failure to
observe it may be due to an equilibrium favoring 2 or
that its formation is very slow. Thus, the relatively fast
formation of 3e must take place, at least in part, via
the alternative pathway outlined in Scheme 1.
Our results demonstrate that 1 and 2 react with
isothiocyanates to give a common type of product,
namely, κ2S,S-dithiocarbamato complexes, and verify
the assumption that silanethiolates and hydrosulfides
have analogous chemistry.
(13) Sato, F.; Nakamura, K.; Sato, M. J . Organomet. Chem. 1974,
67, 141.
(14) Angelici, R. J .; Gingerich, R. G. W. Organometallics 1983, 2,
89.
(15) Vicente, J .; Chicote, M. T.; Abrisqueta, M. D.; Gonzalez-Herrero,
P.; Guerrero, R. Gold Bull. 1998, 31, 126.

40 Organometallics, Vol. 20, No. 1, 2001
Kova´cs et al.
Ta ble 2. Cr ysta llogr a p h ic Da ta a n d Str u ctu r e
Refin em en t for Com p lexes 3c a n d 4a
Cp Ru (P P h 3)S2CNHP h (3d ). A solution of 2 (30 mg, 0.04
mmol) in 0.7 mL of benzene-d6 was treated with phenyl
isothiocyanate (5 µL, 0.04 mmol) at room temperature, and
the reaction was monitored by NMR spectroscopy. Complex 2
was consumed in about 1 h, and a mixture of 3d and 5 (95:5)
was present at this point. Conversion of 5 into 3d was complete
in an additional 2 h. Complex 3d was characterized by NMR
spectroscopy as follows. 1H NMR (C6D6): δ 4.43 (s, 5H, Cp),
6.74 (m, 1H, p-NPh), 6.93 (m, 2H, m-NPh), 7.04 (m, 9H, m,p-
PPh), 7.10 (o-NPh), 7.43 (s, 1H, NH), 7.74 (m, 6H, o-PPh). 13C-
{1H} NMR (C6D6): δ 76.5 (Cp), 119.7 (m-NPh), 123.8 (p-NPh),
3c
4a
empirical formula
C
43H48NPRuS2Si
C72H86N2P2Ru2S4Si2‚
0.7C6H14
774.32
fw
803.07
293(2)
T (K)
293(2)
radiation, λ (Å)
cryst syst
space group
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Mo KR, 0.70930
monoclinic
P21/c
10.689(14)
21.888(12)
16.930(12)
90
94.09(8)
90
3951(6)
4
Mo KR, 0.70930
triclinic
P1
10.660(5)
13.263(7)
15.606(7)
74.92(4)
84.72(4)
85.76(4)
2118(2)
2
128.7 (p-PPh), 134.0 (d, J PC ) 11 Hz, o-PPh), 138.1 (d, J PC
)
38 Hz, ipso-PPh), 138.2 (ipso-NPh); the missing m-PPh doublet
and o-NPh resonances were hidden under those of the solvent.
31P{1H} NMR (C6D6): δ 54.2.
Cp Ru (P P h 3)S2CNHNa p h th (3e). Complex 2 (0.30 g, 0.41
mmol) was dissolved in 40 mL of benzene, and solid 1-naphthyl
isothiocyanate (80 mg, 0.43 mmol) was added at once. The
yellow solution was stirred overnight at room temperature.
The solvent was evaporated under reduced pressure, and the
resulting oily residue was dissolved in CH2Cl2 and filtered
through Celite. The solution was concentrated to about 5 mL
and was layered with hexane in a Schlenk tube. Cooling to
-20 °C gave orange microcrystals. Yield: 0.15 g (0.23 mmol,
57%). Anal. Calcd for C34H28NPRuS2: C, 63.14; H, 4.36; N,
2.17; S, 9.92. Found: C, 63.16; H, 4.61; N, 2.16; S, 9.19. 1H
NMR (C6D6): δ 4.42 (s, 5H, Cp), 7.04 (m, 9H, m,p-Ph), 7.09
(m, 1H, Naphth), 7.25 (m, 2H, Naphth), 7.32, 7.50 (both m,
1H, Naphth), 7.74 (m, 6H, o-Ph), 7.82 (s, 1H, NH), 7.94 (m,
2H, Naphth). 13C{1H} NMR (C6D6): δ 76.5 (Cp), 120.8, 121.2,
125.3, 125.6, 125.9 (2C), 127.0 (all Naphth), 128.7 (p-Ph), 132.7
(Naphth), 134.0 (d, J PC ) 11 Hz, o-Ph), 134.4 (Naphth), 138.3
(d, J PC ) 38 Hz, ipso-Ph), 217.4 (d, J PC ) 5 Hz, S2CN); the
m-Ph doublet and one missing Naphth resonance were hidden
under those of the solvent, but both were detected in CDCl3
at 127.4 (J PC ) 9 Hz) and 128.6, respectively. 31P{1H} NMR
(C6D6): δ 54.2.
Z
Dcalcd (Mg m-3
)
1.350
0.604
1672
1.2138
0.555
812
µ (mm-1
F(000)
)
cryst size (mm)
transmn range
limiting indices
0.38 × 0.28 × 0.22 0.62 × 0.25 × 0.20
0.80 to 0.86
0.77 to 0.85
-13 e h e 13
-16 e k e 16
-19 e l e 19
16 658
-13 e h e 13
-27 e k e 27
-20 e l e 20
no. of reflns collected 30 122
no. of ind reflns (Rint
)
7804 (0.085)
1.069
8329 (0.108)
0.932
GoF on F2
final R indices
(I > 2σ(I))
R indices (all data)
R1 ) 0.0647,
wR2 ) 0.1396a
R1 ) 0.1264,
wR2 ) 0.1697a
R1 ) 0.0670,
wR2 ) 0.1656a
R1 ) 0.1134,
wR2 ) 0.1888a
R1 ) ∑(|Fo| - |Fc|)/∑|Fo|; wR2 ) [∑w(Fo - Fc2)2/∑w(Fo2)2]1/2
.
a
2
215.1 (d, J PC ) 5 Hz, S2CN); the m-Ph resonance was hidden
under that of the solvent.
The solution of 7, containing unreacted 1,4-phenylene
diisocyanate, was “titrated” with additional 2 in benzene-d6,
and concomitant formation of 4b and small amounts of 8
(Table 1) was observed. Complex 4b readily precipitated from
the reaction mixture at room temperature as orange micro-
crystals. The crystalline material is poorly soluble in benzene
or chloroform and insoluble in hexane. Eventually it was
dissolved in DMSO-d6 but recrystallized in the NMR tube
while a 13C NMR spectrum was acquired. This precipitate
could not be redissolved even in hot DMSO-d6. Anal. Calcd
for C54H46N2P2Ru2S4: C, 58.15; H, 4.16; N, 2.51. Found: C,
58.36; H, 4.07; N, 2.23. Some NMR data for 4b are shown in
1,4-[Cp Ru (P P h 3)S2CN(SiiP r 3)]2C6H4 (4a ). This complex
was prepared in the same way as 3a , using 1,4-phenylene
diisothiocyanate (0.13 g, 0.68 mmol). Well-formed orange
crystals readily deposited from CH2Cl2-hexane at room tem-
perature. Yield: 0.97 g (0.62 mmol, 91%). Anal. Calcd for
C
72H86N2P2Ru2S4Si2: C, 60.56; H, 6.07; N, 1.96; S, 8.98.
Found: C, 62.59; H, 7.36; N, 1.85; S, 8.25. Calcd for 4a ‚
1
1.6C6H14: C, 62.59; H, 6.98; N, 1.79; S, 8.19. H NMR (C6D6):
δ 1.09 (d, J ) 7 Hz, 36H, CH3), 1.77 (sept, J ) 7 Hz, 6H, CH),
4.39 (s, 10H, Cp), 7.06 (m, 22H, m,p-Ph+C6H4), 7.65 (m, 12H,
o-Ph). 13C{1H} NMR (C6D6): δ 13.7 (CH), 18.8 (CH3), 77.2 (Cp),
128.5 (C-2,2′,3,3′, C6H4), 130.7 (p-Ph), 133.9 (d, J PC ) 11 Hz,
o-Ph), 138.9 (d, J PC ) 38 Hz, ipso-Ph), 140.3 (C-1,4, C6H4),
228.1 (d, J PC ) 5 Hz, S2CN); the m-Ph doublet was hidden
under the solvent resonances but was observed in CDCl3 at
127.1 (J PC ) 9 Hz). 31P{1H} NMR (C6D6): δ 54.7.
1,4-[Cp Ru (P P h 3)S2CNH]2C6H4 (4b). Complex 2 (50 mg,
0.07 mmol) in 1 mL of benzene-d6 was added to 1,4-phenylene
diisothiocyanate (20 mg, 0.10 mmol) in an NMR tube. The
reaction, monitored by NMR spectroscopy at 22 °C, instantly
consumed 2 and formed yellow-colored 6. The NMR data for 6
are listed in Table 1; the aromatic resonances are as follows.
1H NMR (C6D6): δ 6.94 (m, 18H, m,p-Ph), 7.39 (m, 12H, o-Ph).
13C{1H} NMR (C6D6): δ 122.9 (C-2,2′, C6H4), 125.3 (C-3,3′,
C6H4), 129.5 (p-Ph), 134.1 (br “t”, o-Ph), 137.2 (C-4, C6H4), 138.2
(t, J PC ) 20 Hz, ipso-Ph), 140.2 (C-1, C6H4); the m-Ph doublet
was completely covered by that of the solvent peak.
1
Table 1; resonances in the aromatic region are as follows. H
NMR (C6D6): δ 6.92 (s, 4H, C6H4), 7.03 (m, 18H, m,p-Ph), 7.71
(m, 12H, o-Ph). 13C{1H} NMR (DMSO-d6): δ 120.7 (C-2,2′,3,3′,
C6H4), 128.0 (d, J PC ) 9 Hz, m-Ph), 129.3 (p-Ph), 133.7 (d,
J PC ) 10 Hz, o-Ph), 137.6 (C-1,4, C6H4), 137.9 (d, J PC ) 38 Hz,
ipso-Ph); the S2CN carbon resonance was not identified.
Cp Ru (d p p e)SC(S)NHR (R ) P h (9a ), Na p h th (9b)). To
a solution of CpRu(dppe)SH (30 mg, 0.05 mmol) in 0.7 mL of
benzene-d6 were added phenyl isothiocyanate (6 µL, 0.05
mmol) and 1-naphthyl isothiocyanate (10 mg, 0.05 mmol),
respectively, at room temperature. The first reaction was
complete in about 4 h, while it took 3 days to obtain 9b. When
the reactions were judged complete by NMR, the solvent was
evaporated under reduced pressure to give oily residues. These
were washed with ether to give lemon yellow solids, but
attempts to purify the products by crystallization failed so far.
Both 9a ,b were characterized by 1H, 13C, and 31P NMR
spectroscopy.
Complex 6 completely transformed to 7 overnight at room
temperature to give a red-orange solution. The NMR data for
7 are compiled in Table 1; the aromatic resonances are as
follows. 1H NMR (C6D6): δ 7.04 (m, 9H, m,p-Ph), 7.69 (m, 6H,
o-Ph). 13C{1H} NMR (C6D6): δ 119.8 (C-2,2′, C6H4), 125.8 (C-
3,3′, C6H4), 129.5 (p-Ph), 133.9 (d, J PC ) 11 Hz, o-Ph), 136.7
(C-1, C6H4), 137.3 (C-4, C6H4), 137.8 (d, J PC ) 39 Hz, ipso-Ph),
Data for 9a are as follows. 1H NMR (C6D6): δ 1.73, 2.47
(both m, 2H each, PCH2), 4.55 (s, 5H, Cp), 6.94 (m, 12H, m,p-
PPh), 7.07 (m, 8H, o-PPh), 7.57 (m, 3H, m,p-NPh), 7.81 (m,
2H, o-NPh), 9.40 (s, 1H, NH). 13C{1H} NMR (CDCl3): δ 27.3
(t, J PC ) 23 Hz, CH2P), 82.1 (Cp), 121.3 (m-NPh), 123.9 (p-
NPh), 127.8 (m-NPh), 128.1, 128.5 (both br t, m-PPh), 129.7,

Ruthenium-Assisted Insertion of Isothiocyanates
Organometallics, Vol. 20, No. 1, 2001 41
129.9 (both p-PPh), 132.1 (br t, o-PPh); the weak ipso-NPh and
ipso-PPh resonances were not identified. 31P{1H} NMR
(C6D6): δ 78.7.
All non-hydrogen atoms are anisotropic except for the disor-
dered Cp group in 4a , which was modeled as a variable metric
rigid group. The hydrogen atoms are isotropic and constrained
to the parent site using a riding model. The isotropic factors
were adjusted to 50% higher value of the parent site (methyl)
and 20% higher (others).
Data for 9b are as follows. 1H NMR (C6D6): δ 1.89, 2.42
(both m, 2H each, PCH2), 4.65 (s, 5H, Cp), 6.93 (m, 12H, m,p-
Ph), 7.03 (m, 8H, o-Ph), 7.45, 7.60, 7.75, 8.03 (all m, Naphth),
9.49 (s, 1H, NH). 13C{1H} NMR (CDCl3): δ 82.5 (Cp), 123.0,
124.4, 125.3, 125.7, 125.9, 126.4, 127.9, (all Naphth), 128.3 (br
t, m-Ph), 128.5, 128.6 (both Naphth), 128.7 (br t, m-Ph), 129.4
(Naphth), 129.6, 130.1 (both p-Ph), 131.7, 132.6 (both br t,
o-Ph), 133.9 (t, J PC ) 18 Hz, ipso-Ph). 31P{1H} NMR (C6D6): δ
77.7.
For 4a , the VOID routine of the PLUTON program indicated
an unoccupied volume of 534 Å3 in the unit cell. The SQUEEZE
routine of the same program indicated 68 missed electrons
situated in this void, which correspond to 1.4 molecules of
hexane per unit cell. This has been accounted for in calculating
the absorption coefficient, density, formula weight, and elec-
trons per cell, F(000). The final refinement is against corrected
structure factors produced by the SQUEEZE routine by
subtracting the solvent contribution.
Cr ysta l Str u ctu r e Deter m in a tion of Com p lexes 3c a n d
4a . Orange crystals of both complexes were obtained from
methylene chloride-hexane solutions. Intensity data were
collected on a Rigaku AFC6S diffractometer. Data collection
and structure solution parameters are shown in Table 2. In
both cases, the space group was confirmed by the PLUTON
program.16 Data reduction and absorption correction were
performed using DATRD2 and ABSN, respectively, in NRC-
VAX.17 The structures were solved by the Patterson method
using SHELXS96 and difmap synthesis using SHELXL96.18
Ack n ow led gm en t. The authors thank the Natural
Sciences and Engineering Research Council of Canada
(NSERC) and the Quebec Department of Education for
financial support.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates and thermal parameters, bond lengths and angles,
torsion angles, and structure refinement details and ORTEP
drawings of 3c and 4a with full numbering scheme, as well
as a packing diagram of 4a . This material is available free of
charge via the Internet at http://pubs.acs.org.
(16) Spek, A. L. PLUTON Molecular Graphics Program, University
of Utrecht: Holland, 1995.
(17) Gabe, E. J .; LePage, Y.; Charland, J . P.; Lee, F. L.; White, P.
S. J . Appl. Crystallogr. 1989, 22, 384.
(18) (a) Sheldrick, G. M. SHELXS-96 Program for the Solution of
Crystal Structures; University of Gottingen: Germany, 1996. (b)
Sheldrick, G. M. SHELXL-96 Program for Structure Analysis; Uni-
versity of Gottingen: Germany, 1996.
OM000497L