Reactivities of π-electron-rich phosphorus-nitrogen ligands toward Groups VIB and VIIB metal carbonyl complexes

Article abstract of DOI:10.1016/S0022-328X(00)00475-7

The interaction of (Ph₂PN=)C(Ph)[N(SiMe₃)₂] (L¹) with one equivalent of Mn(CO)₅Br afforded cis-Mn(CO)₄Br-{(Ph₂PN=)C(Ph)[N(SiMe₃) ₂]} (1), which upon boiling in THF gave fac-Mn(CO)₃Br[(Ph₂PNH)C(Ph)(=NSiMe₃)] (2), and with one equivalent of Re(CO)₅X (X = Br or Cl) gave fac-Re(CO)₃X[(Ph₂PNH)C(Ph)(=NH)] [X = Br (3) or Cl (4)] in good yield. Reaction of 1,4-C₆H₄{C(=NPPh₂)[N(SiMe₃) ₂]}₂ (L²) with two equivalents of Mn(CO)₅Br gave the symmetric dimer [cis-Mn(CO)₄Br]₂ {(Ph₂PN=)[N(SiMe₃)₂]C}₂C ₆H₄-1,4 (5), and with two equivalents of Re(CO)₅Br gave the cyclic dimer cyclo-[fac-(Me₂NCHO)Re(CO)₃(μ-Ph₂PO ₂)]₂ (6) upon recrystallization in DMF. Treatment of (NC₅H₄){(Ph₂PN=)C[N(SiMe₃) ₂]}-4 (L³) with one equivalent of (nbd)M(CO)₄ (M = Mo or Cr, nbd = norbornadiene) in THF produced cis-M(CO)₄{(NC₅H₄)-[(Ph ₂PNH)C(=NSiMe₃)]-4} [M = Mo (7) or Cr (8)], and with excess Mn(CO)₅Br led to the trinuclear complex fac-{cis-Mn(CO)₄Br[(NC₅H₄){(Ph ₂PN=)C[N(SiMe₃)₂]}-4]}₂Mn(CO) ₃Br (9) in good yield. Compound 7, in the presence of CdCl₂, hydrolyzed to cis-Mo(CO)₄{(NC₅H₄)[(Ph ₂PNH)C(=NH)]-4} (10). Compound 8 reacted with half an equivalent of Mn(CO)₅Br to give the trinuclear complex fac-[cis-Cr(CO)₄{(NC₅H₄)[(Ph ₂PNH)C(=NSiMe₃)]-4}]₂Mn(CO)₃Br (11). All the new compounds were characterized by spectroscopic and analytical methods and the structures of compounds 1, 3, 6, 9 and 10 were established by X-ray crystallography.

Full text of DOI:10.1016/S0022-328X(00)00475-7

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 612 (2000) 160–171
Reactivities of p-electron-rich phosphorusꢀnitrogen ligands toward
Groups VIB and VIIB metal carbonyl complexes
Wai-Yeung Wong a,*1, Wai-Kwok Wong a,*2, Chaode Sun a, Wing-Tak Wong b
a Department of Chemistry, Hong Kong Baptist Uni6ersity, 224 Waterloo Road, Kowloon Tong, People’s Republic of China
b Department of Chemistry, The Uni6ersity of Hong Kong, Pokfulam Road, Hong Kong, People’s Republic of China
Received 27 April 2000; received in revised form 22 May 2000
Abstract
The interaction of (Ph2PNꢁ)C(Ph)[N(SiMe3)2] (L1) with one equivalent of Mn(CO)5Br afforded cis-Mn(CO)4Br-
{(Ph2PNꢁ)C(Ph)[N(SiMe3)2]} (1), which upon boiling in THF gave fac-Mn(CO)3Br[(Ph2PNH)C(Ph)(ꢁNSiMe3)] (2), and with one
equivalent of Re(CO)5X (X=Br or Cl) gave fac-Re(CO)3X[(Ph2PNH)C(Ph)(ꢁNH)] [X=Br (3) or Cl (4)] in good yield. Reaction
of 1,4-C6H4{C(ꢁNPPh2)[N(SiMe3)2]}2 (L2) with two equivalents of Mn(CO)5Br gave the symmetric dimer [cis-
Mn(CO)4Br]2{(Ph2PNꢁ)[N(SiMe3)2]C}2C6H4-1,4 (5), and with two equivalents of Re(CO)5Br gave the cyclic dimer cyclo-[ fac-
(Me2NCHO)Re(CO)3(m-Ph2PO2)]2 (6) upon recrystallization in DMF. Treatment of (NC5H4){(Ph2PNꢁ)C[N(SiMe3)2]}-4 (L3) with
one equivalent of (nbd)M(CO)4 (M=Mo or Cr, nbd=norbornadiene) in THF produced cis-M(CO)4{(NC5H4)-
[(Ph2PNH)C(ꢁNSiMe3)]-4} [M=Mo (7) or Cr (8)], and with excess Mn(CO)5Br led to the trinuclear complex fac-{cis-
Mn(CO)4Br[(NC5H4){(Ph2PNꢁ)C[N(SiMe3)2]}-4]}2Mn(CO)3Br (9) in good yield. Compound 7, in the presence of CdCl2, hy-
drolyzed to cis-Mo(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNH)]-4} (10). Compound 8 reacted with half an equivalent of Mn(CO)5Br to
give the trinuclear complex fac-[cis-Cr(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNSiMe3)]-4}]2Mn(CO)3Br (11). All the new compounds were
characterized by spectroscopic and analytical methods and the structures of compounds 1, 3, 6, 9 and 10 were established by
X-ray crystallography. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: Chromium; Molybdenum; Manganese; Rhenium; Carbonyl
toward transition metals. Recently we have described
the coordination chemistry of (Ph2PNꢁ)C(Ph)[N-
(SiMe3)2] (L1), C6H4{C(ꢁNPPh2)[N(SiMe3)2]}2-1,4 (L2)
and (NC5H4){(Ph2PNꢁ)C[N(SiMe3)2]}-4 (L3) toward
transition metal complexes and demonstrated that these
ligands, depending on the reaction conditions, could
behave as mono-, bi-, tri- and tetra-dentate ligands
[4–7]. Herein we report the detail study of the reactions
of L1, L2 and L3 toward Groups 6 and 7 metal carbonyl
complexes.
1. Introduction
Phosphorusꢀnitrogen compounds are p-electron-rich
compounds with unusual properties [1]. This has led to
a considerable interest in their syntheses [2] and their
coordination chemistry toward transition metals [3]. We
have been interested in the preparation and the chem-
istry of PꢀN ligands as they are hemilabile ligands
capable of exhibiting unusual coordination chemistry
E-mail address: rwywong@net1.hkbu.edu.hk (W.-Y. Wong).
1 *Corresponding author. Tel.: +852-2339-7074; fax: +852-2339-
7348.
2 *Corresponding author. Tel.: +852-2339-7074; fax: +852-2339-
7348.
0022-328X/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00475-7

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
161
2. Results and discussion
2.1. Reactions of L1 with M(CO)5X (M=Mn, Re)
When Mn(CO)5Br was allowed to react with one
equivalent of (Ph2PNꢁ)C(Ph)[N(SiMe3)2] (L1) in THF
for
1 day, work-up gave red crystals of cis-
Mn(CO)4Br{(Ph2PNꢁ)C(Ph)[N(SiMe3)2]} (1) in moder-
ate yield (60%) after recrystallization from hexane
(Scheme 1). In the terminal carbonyl region, compound
1 exhibited four absorptions at 2085s, 2000vs, 1956vs
and 1921m (sh) cm−1 in the IR spectrum (KBr), and
two doublets at l 217.3 (JPꢀCO=21.9 Hz) and 212.9
(JPꢀCO=12.2 Hz) in the 13C{1H}-NMR spectrum.
These data are indicative of a cis-Mn(CO)4(L)Br com-
pound. The 31P{1H}-NMR spectrum of 1 exhibited a
singlet at l 73.6 for the PPh2 group; and the 13C{1H}-
NMR spectrum displayed a doublet and a singlet at l
171.4 (JPꢀNC=7.3 Hz) and 3.2 for the CꢁN and SiMe3
carbon atoms, respectively.
Crystals of 1 suitable for an X-ray diffraction study
were grown from its hexane solution. A perspective
drawing is shown in Fig. 1. The solid-state structure is
consistent with its spectroscopic data and reveals that
L1 simply acts as a monodentate ligand with the phos-
phino group P(1) coordinated to the MnBr(CO)4 moi-
Scheme 1. 1: M=Mn, X=Br; 2: M=Mn, X=Br; 3: M=Re,
X=Br; 4: M=Re, X=Cl.
Fig. 1. A perspective drawing of the molecular structure of 1.

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W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
X=Cl (4)] in moderate yield. In the carbonyl region,
the IR and 13C{1H}-NMR spectral patterns of both 3
and 4 are characteristic of a fac-Re(CO)3 configuration.
The IR spectrum also exhibited two NH absorptions at
3408m and 3252m cm−1 for 3 and 3408m and 3245s
cm−1 for 4. A singlet at l 75.0 and 77.5 was observed
for the PPh2 group in the 31P{1H}-NMR spectra of 3
and 4, respectively. The 1H-NMR spectrum also
showed two singlets of equal intensity for the two
different NH protons at l 6.58 and 7.76 for 3 and 6.67
and 7.86 for 4. The mass spectrum gave the parent peak
at m/z 653 [(M+1) for 185Re and 79Br] for 3 and 608
[M for 185Re and 35Cl] for 4.
ety. The Mn center adopts an approximately octahedral
geometry with the phosphino group and bromide lig-
and arranged in a cis configuration. The MnꢀC dis-
tances of the two mutually trans-carbonyls are 1.840(9)
,
and 1.864(8) A for Mn(1)ꢀC(1) and Mn(1)ꢀC(4), re-
spectively, and are slightly longer than the MnꢀC dis-
,
tances of 1.822(8) and 1.765(9) A for the carbonyl trans
to the phosphino [P(1)] group and the bromo [Br(1)]
group, respectively. Within the monodentate ligand, the
,
P(1)ꢀN(1) bond length of 1.661(5) A lies in the normal
range for a phosphorusꢀnitrogen bond. The C(17)ꢀN(1)
,
,
(1.291(7) A) and C(17)ꢀN(2) (1.388(7) A) bonds are
,
intermediate between those for single (1.46 A) and
Suitable crystals of compound 3 were grown from a
CH2Cl2/hexane mixture. A perspective drawing is de-
picted in Fig. 2. The solid-state structure reveals that
the (Ph2PNH)C(Ph)(ꢁNH) group acts as a chelate with
the imino group N(1) and phosphino group P(1) coor-
dinated to the metal forming a five-membered ring. The
geometry of the Re atom is approximately octahedral
with a fac-Re(CO)3 configuration. The ReꢀC distances
,
double (1.26 A) bonds indicating some delocalization
about the NꢀCꢀN framework. This is further supported
by the geometry of N(2) of the N(SiMe3)2 group which
is approximately trigonal planar with bond angles of
121.9(4), 121.7(3) and 115.5(4)° for Si(1)ꢀN(2)ꢀC(17),
Si(1)ꢀN(2)ꢀSi(2) and Si(2)ꢀN(2)ꢀC(17), respectively.
This suggests that the lone pair on N(2) is primarily of
p character and has the correct symmetry to interact
with the neighboring empty p* orbital. This p–p*
interaction is reflected in the C(17)ꢀN(2) distance
,
are 1.98(2), 1.87(2) and 1.95(2) A for ReꢀC(1), ReꢀC(2)
and ReꢀC(3), respectively, which reflect the p-acidity of
the ligands trans to the carbonyl groups. Delocalization
about the NꢀCꢀN framework of the five-membered
ring is also observed. The P(1)ꢀN(2), C(4)ꢀN(1) and
,
(1.388(7) A). Similar observation has been reported for
the related molybdenum complex [6].
When 1 was allowed to reflux gently in THF for 4 h,
,
C(4)ꢀN(2) distances are 1.69(2), 1.40(1) and 1.25(2) A,
work-up gave
a
yellow solid of stoichiometry
respectively; and the P(1)ꢀN(2)ꢀC(4) bond angle is
119.8(8)°.
Mn(CO)3Br(C22H25N2SiP)·0.5H2O (2·0.5H2O) in high
yield (90%). Likewise, the thermal reaction of
Mn(CO)5Br with L1 also afforded compound 2. In the
IR spectrum, 2 exhibited three w(CO) absorptions with
a pattern characteristic of a fac-Mn(CO)3 moiety. Com-
paring to 1, these absorptions were shifted to lower
frequencies which is characteristic of an increase in d–p
back bonding from the metal to the carbonyl groups.
The IR spectrum also showed an absorption at 3230s
cm−1 indicating the presence of an NH group. The
31P{1H}-NMR spectrum of 2 exhibited a singlet at l
106.4 for the PPh2 group. The large positive increase in
chemical shift for the PPh2 group from l 73.6 to 106.4
is characteristic of chelating ring formation [8]. Other
than the phenyl resonances, the 1H-NMR spectrum of 2
also displayed two singlets of relative intensity 1:9 at l
6.70 (br) and 0.13 for the NH and SiMe3 protons,
respectively; and the 13C{1H}-NMR spectrum exhibited
a singlet at l 3.6 for the SiMe3 carbon atoms. The mass
spectrum of 2 exhibited the parent peak at m/z 595
[(M+1) for 55Mn and 79Br]. The spectroscopic data are
consistent with the formulation fac-Mn(CO)3Br-
[(Ph2PNH)C(Ph)(ꢁNSiMe3)] for compound 2. A related
chromium complex has been isolated and structurally
characterized [6].
A possible mechanism for the formation of com-
pounds 1–4 is shown in Scheme 1. Following the
reaction of Mn(CO)5Br with L1 to produce compound
1, product 1 then underwent further substitution by
replacing one of the mutually trans-carbonyls with the
amino group of the PꢀN ligand forming a five-mem-
bered ring intermediate I. It is followed by a rapid
1,3-shift to give an intermediate II. Subsequent hydroly-
sis of II afforded compound 2. A similar mechanism
has been proposed for other related complexes [6]. With
Re(CO)5X, the compound underwent further hydrolysis
to give compound 3 (X=Br) or 4 (X=Cl).
2.2. Reactions of L2 with M(CO)5X (M=Mn, Re)
When 1,4-C6H4{C(NPPh2)[N(SiMe3)2]}2 (L2) was al-
lowed to react with two equivalents of Mn(CO)5Br in
THF for 1 day, a yellow solid of stoichiometry
[Mn(CO)4Br]2[C44H60N4P2Si4]·0.5C4H8O (5·0.5C4H8O)
was obtained in moderate yield (40%). Compound 5
has been characterized as a symmetric dimer [cis-
Mn(CO)4Br]2{(Ph2PNꢁ)[N(SiMe3)2]C}2C6H4-1,4 with
L2 linking the two Mn(CO)4Br moieties together via the
two phosphino groups leaving the two amino groups
uncoordinated. The proposed structure for compound 5
is shown below. The 31P{1H}-NMR spectrum of 5
The interaction of Re(CO)5X (X=Br or Cl) with one
equivalent of L1 in refluxing THF gave white crystals of
fac-Re(CO)3X[(Ph2PNH)C(Ph)(ꢁNH)] [X=Br (3);

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
163
Fig. 2. A perspective drawing of the molecular structure of 3.
of compound 6 was ascertained by an X-ray diffraction
study to be consistent with the formulation cyclo-[ fac-
(Me2NCHO)Re(CO)3(m-Ph2PO2)]2. A perspective draw-
ing is shown in Fig. 3. Structural analysis revealed that
the phosphorus atoms of the L2 ligand were oxidized to
the Ph2PO−2 fragments with concomitant cleavage of
the PꢀN bonds. Compound 6 is centro-symmetric with
the two rhenium atoms linked together via two m-
Ph2PO−2 moieties through their two oxygen atoms
forming an eight-membered Re2O4P2 ring in a zig–zag
conformation. The geometries of the two rhenium
atoms are approximately octahedral with the three ter-
minal carbonyl ligands adopting a fac configuration.
showed only a singlet at l 68.4, indicating the presence
of two equivalent PPh2 groups. The chemical shift of
the PPh2 groups is similar to that of 1 and much more
upfield than that of 2 suggesting no chelate ring forma-
tion. Compound 5 also exhibited a singlet at l 0.11 in
1
the H-NMR spectrum and a singlet at l 3.1 in the
13C{1H}-NMR spectrum for the trimethylsilyl groups.
,
The ReꢀC distances are 1.89(2), 1.88(2) and 1.93(2) A
for Re(1)ꢀC(1), Re(1)ꢀC(2) and Re(1)ꢀC(3), respec-
tively. The Ph2PO−2 anion adopts a deformed tetrahe-
dron with the O(5)ꢀP(1)ꢀO(6*) bond angle of 116.5(5)°.
The P(1)ꢀO(5) and P(1)ꢀO(6*) distances of 1.503(9) and
Treatment of Re(CO)5Br with L2 under the same
conditions led to the formation of a white solid, which
was insoluble in common organic solvents. However,
the solid dissolved in hot DMF and its color changed
from white to yellow. Yellow crystals of stoichiometry
Re2(CO)6(C30H34N2O6P2) (6) with two DMF solvate
molecules were obtained in 40% yield after recrystalliza-
tion from a hot DMF solution. The molecular structure
,
1.521(9) A, respectively, are slightly shorter than PꢀO
,
single bond (ꢀ1.6 A) and are nearly equal to each
other, indicating delocalization about the OꢀPꢀO
framework.
The spectroscopic data of 6 are consistent with its
solid-state structure. The 31P{1H}-NMR spectrum in

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W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
Fig. 3. A perspective drawing of the molecular structure of 6.
1
d7-DMF exhibited a singlet at l 35.4 for the two
m-diphenylphosphate groups. The IR spectrum (KBr)
exhibited four absorptions at 2019s, 1905vs, 1889vs and
1875vs cm−1 for the terminal carbonyls of the two
fac-Re(CO)3 moieties and an absorption at 1647s cm−1
for the CꢁO group of the coordinated DMF molecules.
The mass spectral parent peak at m/z 1047 (M for
185Re) also agrees well with its formulation.
The H-NMR spectrum of each complex also displayed
resonances of relative intensity 1:9 for the NH and
Me3Si protons; and their 13C{1H}-NMR spectrum a
singlet at l 3.6 for the SiMe3 carbon atoms. The mass
spectrum showed the parent peak at m/z 587 [(M+1)
for 98Mo] for 7 and 541 (M for 55Cr) for 8. Compounds
7 and 8 can satisfactorily be formulated as cis-
M(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNSiMe3)]-4}. The struc-
ture of 7 was also confirmed by an X-ray diffraction
study [9].
2.3. Reactions of L3 with (nbd)M(CO)4 (M=Cr, Mo)
or Mn(CO)5Br
When Mn(CO)5Br was allowed to react with L3 in a
3:2 molar ratio, red crystals of a trinuclear complex
fac-{cis-Mn(CO)4Br[(NC5H4){(Ph2PNꢁ)C[N(SiMe3)2]}-
4]}2Mn(CO)3Br (9) were obtained in good yield (58%)
after recrystallization from a hexane solution. The
31P{1H}-NMR spectrum of 9 exhibited a singlet at l
73.6 for the PPh2 group. The chemical shift is similar to
that of 1. Compound 9 also showed a singlet at l 0.17
When (nbd)M(CO)4 (M=Cr or Mo) was allowed to
react with one equivalent of (NC5H4){(Ph2PNꢁ)-
C[N(SiMe3)2]}-4 (L3) in THF for 1 day, yellow crystals
of stoichiometry M(CO)4(C21H24N3SiP) [M=Mo (7);
M=Cr (8)] were isolated in moderate yields (Scheme
2). Compounds 7 and 8 exhibited similar w(CO) absorp-
tion patterns in their IR spectra, which are indicative of
a cis-M(CO)4LL% complex. An NH absorption was also
evident at 3449w for 7 and 3448w cm−1 for 8. The
31P{1H}-NMR chemical shifts at l 89.9 (7) and 112.3
(8) are characteristic of chelating ring formation [8].
1
in the H-NMR spectrum and a singlet at l 3.2 in the
13C{1H}-NMR spectrum for the SiMe3 groups. Good
quality crystals of 9 were grown from a hexane solution
and the molecular structure is shown in Fig. 4. The
three Mn centers are linked together via two L3 ligands,
which behave as bridging ligands. All three Mn centers

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
165
adopt an approximately octahedral geometry with the
two pyridyl nitrogen atoms N(1) and N(4) coordinating
to the central metal Mn(1) in a cis configuration and
the two phosphino groups coordinating to the terminal
metal centers cis to the bromine atoms. For the bridg-
ing ligand, the geometry of N(3) of the N(SiMe3)2
group is approximately trigonal planar with bond an-
gles of 114(1), 120(1) and 124(1)° for Si(2)-N(3)-C(17),
Si(1)-N(3)-Si(2) and Si(1)-N(3)-C(17), respectively. Sim-
ilar to 1, this indicates that the lone pair on N(4) has
primarily p character and the correct symmetry to
interact with the neighboring empty p* orbital, as re-
,
vealed by the C(17)ꢀN(3) distance (1.32(3) A). A similar
geometry is also observed on N(6) of the N(SiMe3)2
moiety with bond angles of 116(1), 120(1) and 122(1)°
for Si(3)ꢀN(6)ꢀC(41), Si(4)ꢀN(6)ꢀC(41) and Si(3)ꢀN(6)ꢀ
Si(4), respectively.
Further attempts to react compound 7 with half an
equivalent of CdCl2 in THF for 1 day at ambient
temperature did not afford any Cd-containing product.
Scheme 2.
Fig. 4. A perspective drawing of the molecular structure of 9. Hydrogen atoms are omitted for clarity.

166
W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
Fig. 5. A perspective drawing of the molecular structure of 10.
slightly longer than the MoꢀC distances of 1.962(6) and
Instead, a yellow solid of cis-Mo(CO)4{(NC5H4)-
[(Ph2PNH)C-(ꢁNH)]-4} (10) was obtained in 50% yield.
The IR spectrum (KBr) of 10 exhibited the characteris-
tic absorption pattern of a cis-M(CO)4LL% complex in
the carbonyl region, and an NH absorption at 3368s
cm−1. The 31P{1H}-NMR spectrum exhibited a singlet
,
2.000(6) A for the carbonyl trans to the imino N(1) and
phosphino P(1) groups, respectively. Within the biden-
tate iminophosphine ligand, the P(1)ꢀN(1), C(5)ꢀN(1)
and C(5)ꢀN(2) distances are 1.711(4), 1.369(6) and
,
1.276(6) A, respectively, and the P(1)ꢀN(1)ꢀC(5) bond
1
angle is 119.8(3)°.
at l 98.8 for its PPh2 group. The H-NMR spectrum
Another new compound fac-[cis-Cr(CO)4{(NC5H4)-
[(Ph2PNH)C(ꢁNSiMe3)]-4}]2Mn(CO)3Br (11) was form-
ed upon the reaction between Mn(CO)5Br and two
equivalents of 8 and compound 11 was isolated as a
yellow solid in good yield (81%). The presence of NH
also exhibited two broad multiplets of relative intensity
1:1 for the NH protons at l 6.24 and 7.56. The mass
spectrum exhibited the parent peak at m/z 515 (M for
98Mo). The structure of 10 was established by X-ray
crystallography.
groups was shown by an IR absorption at 3347w cm−1
.
Yellow crystals of 10 were grown from a dichloro-
methane–hexane mixture. A perspective drawing of 10
is shown in Fig. 5. Structural analysis revealed that the
SiMe3 group had undergone hydrolysis to give a chelate
ligand (HNꢁ)C(4-C5H4N)(NHPPh2) with the imino
group N(1) and the phosphino group P(1) coordinated
to the Mo(CO)4 moiety. The geometry of Mo is ap-
proximately octahedral adopting a cis-Mo(CO)4LL%
configuration. The MoꢀC distances of the two mutually
The 31P{1H}-NMR spectrum of 11 displayed a singlet
at l 114.5 for the PPh2 groups and showed no signifi-
cant change in the chemical shift as compared with 8.
1
The H-NMR spectrum of 11 in CD2Cl2 exhibited two
singlets of relative intensity 1:9 at l 6.75 and 0.12 for
the NH and SiMe3 protons, respectively. Also in the
1H-NMR spectrum, the a- and b-H of the pyridyl
group of 11 appeared at l 8.89 and 7.26, respectively,
corresponding to a shift of ca. 0.17 and 0.03 ppm as
compared with the a- (l 8.66) and b-H (l 7.23) of the
pyridyl group of 8, indicating MnꢀN bond formation.
,
A for
trans-carbonyls are 2.021(6) and 2.017(7)
Mo(1)ꢀC(1) and Mo(1)ꢀC(3), respectively, and are

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
167
3. Experimental
3.3. Preparation of
fac-{[Mn(CO)3Br][(Ph2PNH)C(Ph)(ꢁNSiMe3)]} (2)
3.1. General procedures
A solution of 1 (0.10 g, 0.14 mmol) in THF (10 cm3)
was heated to reflux for 4 h. After cooling to r.t., the
resulting yellow solution was evaporated to dryness to
give a yellow powder, which was washed with hexane
(2×5 cm3) and dried in vacuo. Yield: 78 mg, 90%, m.p.
161–163°C (dec.) (Anal. Found: C, 49.8; H, 4.3; N, 4.5.
Calc. for C25H25BrMnN2O3PSi·0.5H2O: C, 49.7; H, 4.3;
N, 4.6%). IR (cm−1, in KBr): 3230s w(NH), 2021vs,
1940vs, 1906vs w(CO). NMR (C6D6): 31P{1H}, l 106.4
(br, s). 13C{1H}, carbonyl, l 224.4 (br, m); CꢁN, 173.7
(d, J=17.1 Hz); phenyl, 137.6 (s), 137.0 (d, J=23.2
Hz), 133.8 (d, J=11.0 Hz), 132.0 (s), 131.4 (d, J=9.8
Hz), 130.7 (s), 130.1 (d, J=12.2 Hz), 129.5 (d, J=9.8
All reactions were carried out under an atmosphere
of dry nitrogen. Solvents were dried by standard proce-
dures, distilled and deaerated prior to use. All chemi-
cals used were of reagent grade, obtained from the
Aldrich Chemical Company and, where appropriate,
degassed before use. Mn(CO)5Br and Re(CO)5X (X=
Br or Cl) were purchased from Strem Chemicals Inc.
The compounds (Ph2PNꢁ)C(Ph)[N(SiMe3)2] [6],
C6H4{C(ꢁNPPh2)[N(SiMe3)2]}2-1,4 [6], (NC5H4){(Ph2-
PNꢁ)C[N(SiMe3)2]}-4 [7], and M(CO)4(nbd) (M=Cr,
Mo) [10] were prepared according to literature meth-
ods. Microanalyses were performed by the Shanghai
Institute of Organic Chemistry, Chinese Academy of
Sciences, China. Infrared spectra (KBr pellets) were
recorded on a Nicolet Nagna-IR 550 spectrometer,
NMR spectra on a JEOL EX270 spectrometer. Chemi-
1
Hz), 128.8 (d, J=9.8 Hz) and 126.6 (br, s). H, phenyl,
l 7.90–7.84 (2H, m) and 7.61–7.45 (13H, m); NH, 6.70
(1H, br, s); N(SiMe3), 0.13 (9H, s). LRMS m/z: 595
(M+1), 510 (M−3CO) and 431 (M−Br−3CO) for
55Mn and 79Br.
1
cal shifts of H and 13C{1H}-NMR spectra were refer-
enced to internal deuterated solvents and then
recalculated to SiMe4 (l 0.00), those of 31P{1H}-NMR
spectra were referenced to external 85% H3PO4. Low-
resolution mass spectra (LRMS) were obtained on a
Finnigan MAT SSQ-710 spectrometer in FAB (posi-
tive-ion) mode and are reported as m/z.
3.4. Preparation of
fac-Re(CO)3Br[(Ph2PNH)C(Ph)(ꢁNH)] (3)
A mixture of Re(CO)5Br (0.10 g, 0.24 mmol) and L1
(0.11 g, 0.24 mmol) in THF (12 cm3) was refluxed for 2
h. The resulting pale yellow solution was allowed to
cool down to r.t. and then pumped to dryness. The
residue was washed with hexane (2×5 cm3) and then
recrystallized from a dichloromethane–hexane mixture
to give white crystals, which were filtered and dried in
vacuo. Yield: 0.09 g, 60%, m.p. 202–204°C (dec.)
(Anal. Found: C, 39.7; H, 2.5; N, 4.1. Calc. for
C22H17BrN2O3PRe·0.25CH2Cl2: C, 39.5; H, 2.6; N,
4.2%). IR (cm−1, in KBr): 3408m, 3252m w(NH),
2028vs, 1943vs, 1871vs w(CO). NMR (CDCl3): 31P{1H},
l 75.0 (s). 13C{1H}, carbonyl, l 194.3, 191.5, 190.4 and
188.5 (d, J=7.3 Hz); CꢁN, 173.3 (d, J=14.6 Hz);
phenyl, 133.2, 132.9 (d, J=6.1 Hz), 132.0, 131.5, 130.6
(d, J=13.4 Hz), 129.6, 128.9 (dd, J=11 Hz, J=19.5
3.2. Preparation of
cis-Mn(CO)4Br{(Ph2PNꢁ)C(Ph)[N(SiMe3)2]} (1)
A solution of L1 (0.70 g, 1.50 mmol) in THF (10 cm3)
was added to a stirring solution of Mn(CO)5Br (0.40 g,
1.50 mmol) in THF (20 cm3) at −78°C. The reaction
mixture was allowed to warm to room temperature
(r.t.) slowly and stirred for 1 day to give a golden
yellow solution. The resulting solution was pumped to
dryness and then extracted with hexane (2×10 cm3) to
give a red solution after filtration. The filtrate was
concentrated to ca. 10 cm3 and cooled to −20°C to
give red crystals, which were filtered off and dried in
vacuo. Yield: 0.63 g, 60%, m.p. 119–121°C (dec.)
(Anal. Found: C, 50.1; H, 4.9; N, 4.0. Calc. for
C29H33BrMnN2O4PSi2: C, 50.1; H, 4.8; N, 4.0%). IR
(cm−1, in KBr): 2085s, 2000vs, 1956vs, 1921m (sh)
w(CO). NMR (C6D6): 31P{1H}, l 73.6 (br, s). 13C{1H},
carbonyl, l 217.3 (br, d, J=21.9 Hz) and 212.8 (br, d,
J=12.2 Hz); CꢁN, 171.4 (d, J=7.3 Hz); phenyl, 139.5
(d, J=4.9 Hz), 137.1 (s), 137.1 (d, J=43.9 Hz), 132.7
(d, J=9.8 Hz), 130.1 (d, J=2.4 Hz), 129.7, 128.4,
1
Hz) and 126.6. H, phenyl, 7.83–7.47 (15H, m); NH,
7.76 (1H, br, s) and 6.58 (1H, br, s). LRMS m/z: 653
(M+1), 624 (M−CO), 573 (M−Br), 545 (M−Br−
CO) and 489 (M−Br−3CO) for 185Re and 79Br.
3.5. Preparation of
fac-Re(CO)3Cl[(Ph2PNH)C(Ph)(ꢁNH)] (4)
This compound was prepared as described for 3.
Re(CO)5Cl (0.20 g, 0.54 mmol) and L1 (0.24 g, 0.54
mmol) were used. White crystals of 4 were obtained
from a dichloromethane–hexane mixture. Yield: 0.23 g,
70%, m.p. 185–187°C (dec.) (Anal. Found: C, 41.4; H,
3.1; N, 4.0. Calc. for C22H17ClN2O3PRe·1.5H2O: C,
41.5; H, 3.1; N, 4.4%). IR (cm−1, in KBr): 3408m,
1
127.8 and 127.6; N(SiMe3)2, 3.2 (s). H, phenyl, l 7.64
(4H, m), 7.39 (3H, m), 6.87 (6H, m) and 6.69 (2H, m);
N(SiMe3)2, 0.21 (18H, br, s). LRMS m/z: 615 (M−Br),
582 (M−4CO), 557 (M−Br−2CO) and 501 (M−
Br−4CO) for 55Mn and 79Br.

168
W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
3245s w(NH), 2030vs, 1940vs, 1870vs w(CO). NMR
(CDCl3): 31P{1H}, l 77.5 (s). 13C{1H}, carbonyl, l
195.5 (d, J=4.7 Hz), 191.1 (d, J=78.0 Hz) and 188.9
(d, J=8.5 Hz); CꢁN, 173.5 (d, J=15.9 Hz); phenyl,
135.0 (d, J=52.4 Hz), 133.2 (d, J=12.1 Hz), 132.9,
132.1, 131.5, 130.6 (d, J=12.2 Hz), 129.6, 128.9 (t,
2DMF−5CO) and 806 (M+2−2DMF−6CO) for
185Re.
3.8. Preparation of
cis-Mo(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNSiMe3)]-4} (7)
1
J=11 Hz) and 126.7. H, phenyl, 7.84–7.77 (2H, m)
A solution of (nbd)Mo(CO)4 (0.39 g, 1.28 mmol) in
THF (20 cm3) was added to a stirring solution of L3
(0.58 g, 1.28 mmol) in THF (15 cm3) at 0°C. The
resulting solution was allowed to warm to r.t. slowly
and stirred for 1 day to give a red solution. The
solution was filtered and pumped to dryness to give an
orange–red residue. The residue was washed with a 1:1
diethyl ether–hexane mixture (3×5 cm3), redissolved
in dichloromethane (5 cm3) and filtered. A layer of
hexane was then laid over the filtrate. Yellow block
crystals were obtained after standing for 2 days at r.t.
The crystals were filtered and dried in vacuo. Yield:
0.28 g, 37%, m.p. 140–142°C (dec.) (Anal. Found: C,
50.9; H, 4.1; N, 6.9. Calc. for C25H24MoN3O4PSi: C,
51.1; H, 4.1; N, 7.2%). IR (cm−1, in KBr): 3449w
w(NH), 2018s, 1902vs, 1879vs, 1846vs w(CO). NMR
(CD2Cl2): 31P{1H}, l 89.9 (s). 13C{1H}, carbonyl, l
220.9 (d, J=8.5 Hz), 216.8 (d, J=36.5 Hz), 216.6 and
208.0 (d, J=9.8 Hz); CꢁN, 167.1 (d, J=18.2 Hz);
pyridyl, 150.9 (C2,6), 131.1 (C4) and 121.8 (C3,5); phenyl,
145.2 (d, J=6.1 Hz), 137.3 (d, J=39.0 Hz), 130.9 (d,
J=15.6 Hz) and 129.3 (d, J=11.0 Hz); N(SiMe3), 3.6
and 7.66–7.47 (13H, m); NH, 7.86 (1H, br, s) and 6.67
(1H, br, s); LRMS m/z: 608 (M), 573 (M−Cl), 545
(M−CO−Cl), 524 (M−3CO) and 489 (M−3CO−
Cl) for 187Re and 35Cl.
3.6. Preparation of[cis-Mn(CO)4Br]2{(Ph2PNꢁ)-
[(Me3Si )2N]C}2C6H4-1,4 (5)
A solution of L2 (0.62 g, 0.76 mmol) in THF (10 cm3)
was added to a stirring solution of Mn(CO)5Br (0.41 g,
1.50 mmol) in THF (30 cm3) at −78°C. After stirring
at −78°C for 30 min, the solution was allowed to
warm to r.t. and stirred for 1 day to give a golden
yellow solution. The resultant solution was filtered and
concentrated to ca. 5 cm3. Hexane (5 cm3) was subse-
quently added to the concentrate to give a yellow–or-
ange precipitate which was washed with diethyl ether
(2×5 cm3) and then dried in vacuo. Yield: 0.43 g, 43%,
m.p. 124–126°C (dec.) (Anal. Found: C, 48.0; H, 4.8;
N, 4.2. Calc. for C52H60Br2Mn2N4O8P2Si4·5C4H8O: C,
48.1; H, 4.7; N, 4.2%). IR (cm−1, in KBr): 2085s,
2015vs, 2000vs, 1956s, 1912m w(CO). NMR (CDCl3):
31P{1H}, l 68.4 (s). 13C{1H}, carbonyl, l 211.5 (m) and
207.2; CꢁN, 169.4 (d, J=7.3 Hz); phenylene and
phenyl, 140.6, 138.0, 137.3, 132.0 (d, J=9.7 Hz), 130.4
(d, J=7.3 Hz) and 128.0 (d, J=9.7 Hz); SiMe3, 3.1
1
(br, s). H, pyridyl, l 8.71 (2H2,6, d, J=5.9 Hz) and
7.23 (2H2,3, m); phenyl, 7.56–7.44 (10H, m), NH, 6.28
(1H, br, m), N(SiMe3), 0.09 (9H, br, s). LRMS m/z:
587 (M), 559 (M−CO), 531 (M−2CO) and 475 (M−
4CO) for 98Mo.
1
(br, s). H, phenylene and phenyl, l 7.50–7.40 (24H,
m); SiMe3, 0.11 (36H, br, s). LRMS m/z: 1088 (M−
8CO), 1009 (M−8CO−Br), 955 (M−CO−Br−
Mn), 929 (M−CO−2Br) and 873 (M−8CO−2Br−
Mn) for 55Mn and 79Br.
3.9. Preparation of
cis-Cr(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNSiMe3)]-4} (8)
This compound was prepared as described for 7.
(nbd)Cr(CO)4 (0.22 g, 0.86 mmol) and L3 (0.58 g, 1.28
mmol) were used. Yellow block crystals were obtained.
Yield: 0.29 g, 62%, m.p. 173–175°C (dec.) (Anal.
Found: C, 55.1; H, 4.4; N, 7.5. Calc. for
3.7. Preparation of cyclo-
[fac-(Me2NCHO)Re(CO)3(v-Ph2PO2)] (6)
2
Re(CO)5Br (0.10 g, 0.24 mmol) and L2 (0.10 g, 0.12
mmol) in THF (10 cm3) were stirred under reflux for 1
day. The suspension was filtered off to give a white
solid, which was washed with THF (5 cm3), dried in
vacuo, redissolved in hot DMF and filtered to give a
yellow solution. After the solution was cooled down to
ambient temperature, yellow block crystals were ob-
tained. Yield: 0.10 g, 40%, m.p. 172–174°C (dec.)
(Anal. Found: C, 39.9; H, 3.8; N, 4.3. Calc. for
C36H34N2O12P2Re2·2C3H7NO: C, 39.8; H, 3.8; N,
4.4%). IR (cm−1, in KBr): 2019s, 1905vs, 1889vs,
1875vs w(CO). NMR (d7-DMF): 31P{1H}, l 35.4 (s).
LRMS m/z: 1047 (M+2−DMF), 974 (M+2−
2DMF), 918 (M+2−2DMF−2CO), 834 (M+2−
C25H24CrN3O4PSi: C, 55.4; H, 4.4; N, 7.8%). IR (cm−1
,
in KBr): 3448w w(NH), 2009s, 1904vs, 1875vs, 1842vs
w(CO). NMR (CD2Cl2): 31P{1H}, l 112.3 (s). 13C{1H},
carbonyl, l 228.7 (d, J=13.4 Hz), 227.4 (d, J=4.1 Hz)
and 219.2 (d, J=15.9 Hz); CꢁN, 166.9 (d, J=20.7 Hz);
pyridyl, 150.8 (C2,6), 131.1 (C4) and 121.9 (C3,5); phenyl,
145.2 (d, J=4.9 Hz), 137.3 (d, J=39.0 Hz), 130.9 (d,
J=13.4 Hz) and 129.2 (d, J=9.7 Hz); N(SiMe3), 3.6
1
3
(br, s). H: pyridyl, l 8.66 (2H2,6, d, J=4.6 Hz) and
3
7.23 (2H3,5, d, J=2.4 Hz); phenyl, 7.61 (4H, m) and
7.23 (6H, m); NH, 6.85 (1H, br, m); N(SiMe3), 0.11
(9H, br, s). LRMS m/z: 541 (M), 513 (M−CO), 457
(M−3CO) and 429 (M−4CO) for 52Cr.

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
169
Table 1
,
Selected bond lengths (A) and angles (°) for compounds 1, 3, 6, 9 and 10
Compound 1
Mn(1)ꢀP(1)
Mn(1)ꢀC(2)
P(1)ꢀN(1)
2.382(2)
1.822(8)
1.661(5)
1.779(5)
Mn(1)ꢀBr(1)
Mn(1)ꢀC(3)
N(1)ꢀC(17)
N(2)ꢀSi(2)
2.517(1)
1.765(9)
1.291(7)
1.777(5)
Mn(1)ꢀC(1)
Mn(1)ꢀC(4)
N(2)ꢀC(17)
1.840(9)
1.864(8)
1.388(7)
N(2)ꢀSi(1)
P(1)ꢀMn(1)ꢀBr(1)
P(1)ꢀMn(1)ꢀC(3)
N(1)ꢀC(17)ꢀN(2)
Si(2)ꢀN(2)ꢀC(17)
98.64(5)
90.7(2)
119.2(5)
115.5(4)
P(1)ꢀMn(1)ꢀC(1)
P(1)ꢀMn(1)ꢀC(4)
Si(1)ꢀN(2)ꢀSi(2)
87.7(2)
88.8(2)
121.7(3)
P(1)ꢀMn(1)ꢀC(2)
P(1)ꢀN(1)ꢀC(17)
Si(1)ꢀN(2)ꢀC(17)
178.4(2)
133.7(4)
121.9(4)
Compound 3
Re(1)ꢀBr(1)
Re(1)ꢀC(1)
P(1)ꢀN(2)
2.642(2)
1.98(2)
1.69(2)
Re(1)ꢀP(1)
Re(1)ꢀC(2)
N(2)ꢀC(4)
2.412(3)
1.87(2)
1.25(2)
Re(1)ꢀN(1)
Re(1)ꢀC(3)
N(1)ꢀC(4)
2.176(10)
1.95(2)
1.40(1)
P(1)ꢀN(2)ꢀN(1)
P(1)ꢀRe(1)ꢀC(2)
Re(1)ꢀN(1)ꢀC(4)
76.3(3)
178.6(5)
125.4(8)
P(1)ꢀRe(1)ꢀBr(1)
P(1)ꢀRe(1)ꢀC(3)
N(1)ꢀC(4)ꢀN(2)
88.96(8)
89.6(5)
117(1)
P(1)ꢀRe(1)ꢀC(1)
P(1)ꢀN(2)ꢀC(4)
Re(1)ꢀP(1)ꢀN(2)
171.4(4)
119.8(8)
101.0(4)
Compound 6
Re(1)ꢀO(4)
Re(1)ꢀC(1)
P(1)ꢀO(5)
2.182(10)
1.89(2)
1.503(9)
Re(1)ꢀO(5)
Re(1)ꢀC(2)
P(1)ꢀO(6*)
2.167(8)
1.88(2)
1.521(9)
Re(1)ꢀO(6)
Re(1)ꢀC(3)
2.149(8)
1.93(2)
O(4)ꢀRe(1)ꢀO(5)
O(4)ꢀRe(1)ꢀC(2)
O(5)ꢀP(1)ꢀO(6*)
O(5)ꢀP(1)ꢀC(7)
O(6*)ꢀP(1)ꢀC(13)
80.4(3)
175.7(5)
116.5(5)
111.2(6)
111.7(6)
O(4)ꢀRe(1)ꢀO(6)
O(4)ꢀRe(1)ꢀC(3)
Re(1)ꢀO(6)ꢀP(1*)
O(5)ꢀP(1)ꢀC(13)
78.4(3)
97.4(5)
130.5(5)
104.6(6)
O(4)ꢀRe(1)ꢀC(1)
Re(1)ꢀO(5)ꢀP(1)
O(5)ꢀRe(1)ꢀO(6)
O(6*)ꢀP(1)ꢀC(7)
93.8(5)
130.4(6)
81.2(3)
106.6(6)
Compound 9
Mn(1)ꢀBr(1)
Mn(1)ꢀN(1)
Mn(1)ꢀN(4)
Mn(1)ꢀC(1)
Mn(1)ꢀC(2)
Mn(1)ꢀC(3)
P(1)ꢀN(2)
2.534(5)
2.07(2)
2.07(2)
1.74(3)
1.80(3)
1.79(3)
1.66(2)
1.33(3)
Mn(2)ꢀBr(2)
Mn(2)ꢀP(1)
Mn(2)ꢀC(4)
Mn(2)ꢀC(5)
Mn(2)ꢀC(6)
Mn(2)ꢀC(7)
P(2)ꢀN(5)
2.494(6)
2.372(7)
2.18(3)
1.90(4)
1.83(4)
1.82(3)
1.68(2)
1.32(3)
Mn(3)ꢀBr(3)
Mn(3)ꢀP(2)
Mn(3)ꢀC(8)
Mn(3)ꢀC(9)
Mn(3)ꢀC(10)
Mn(3)ꢀC(11)
N(2)ꢀC(17)
N(6)ꢀC(41)
2.533(6)
2.340(8)
1.74(6)
1.88(4)
1.75(3)
1.88(3)
1.27(3)
1.36(3)
N(5)ꢀC(41)
N(3)ꢀC(17)
N(1)ꢀMn(1)ꢀN(4)
N(2)ꢀC(17)ꢀN(3)
Si(1)ꢀN(3)ꢀC(17)
Si(3)ꢀN(6)ꢀC(41)
85.7(7)
123(3)
124(1)
116(1)
P(1)ꢀN(2)ꢀC(17)
N(5)ꢀC(41)ꢀN(6)
Si(2)ꢀN(6)ꢀC(41)
Si(4)ꢀN(6)ꢀC(41)
136(1)
119(1)
114(1)
120(1)
P(2)ꢀN(5)ꢀC(41)
Si(1)ꢀN(3)ꢀSi(2)
Si(3)ꢀN(6)ꢀSi(4)
135(1)
120(1)
122(1)
Compound 10
Mo(1)ꢀP(1)
Mo(1)ꢀC(2)
P(1)ꢀN(1)
2.483(1)
1.962(6)
1.711(4)
Mo(1)ꢀN(2)
Mo(1)ꢀC(3)
N(1)ꢀC(5)
2.246(4)
2.017(7)
1.369(6)
Mo(1)ꢀC(1)
Mo(1)ꢀC(4)
N(2)ꢀC(5)
2.021(6)
2.000(6)
1.276(6)
P(1)ꢀMo(1)ꢀN(2)
P(1)ꢀMo(1)ꢀC(3)
Mo(1)ꢀN(2)ꢀC(5)
74.51(1)
89.8(2)
124.6(3)
P(1)ꢀMo(1)ꢀC(1)
P(1)ꢀMo(1)ꢀC(4)
N(1)ꢀC(5)ꢀN(2)
91.7(2)
167.9(2)
119.2(4)
P(1)ꢀMo(1)ꢀC(2)
Mo(1)ꢀP(1)ꢀN(1)
C(5)ꢀN(1)ꢀP(1)
102.7(2)
101.6(1)
119.8(3)
3.10. Preparation of fac-{cis-Mn(CO)4Br[(NC5H4)-
{(Ph2PNꢁ)C[N(SiMe3)2]}-4]}2Mn(CO)3Br (9)
solution was filtered, pumped to dryness and then
extracted with hexane (10 cm3) to give a red solution
after filtration. The filtrate was then cooled to −20°C
to give red crystals, which were filtered off and dried in
vacuo. Yield: 0.67 g, 58%, m.p. 155–157°C (dec.)
(Anal. Found: C, 44.9; H, 4.4; N, 5.5. Calc. for
C59H64Br3Mn3N6O11P2Si4·0.5C6H14: C, 45.0; H, 4.3; N,
5.1%). IR (cm−1, in KBr): 2087vs, 2027vs, 1999vs,
A
solution of L3 (0.90 g, 2.0 mmol) in
dichloromethane (15 cm3) was added to a solution of
Mn(CO)5Br (1.65 g, 6 mmol) in THF (20 cm3) at
ambient temperature and the solution mixture was al-
lowed to react overnight to give a red solution. The

170
W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
1945vs, 1906vs w(CO). NMR (C6D6): 31P{1H}, l 78.1
(br, s). 13C{1H}, CꢁN, l 167.6 (d, J=8.5 Hz); pyridyl
and phenyl, 154.6 (d, J=4.9 Hz), 147.1 (d, J=4.8 Hz),
(6H, m); pyridyl, 8.74 (2H2,6, d, J=5.9 Hz) and 7.36
(2H3,5, d, J=6.2 Hz); NH, 7.56 (1H, br, m) and 6.24
(1H, br, m). LRMS (FAB: positive mode) m/z: 515 (M)
and 403 (M−4CO) for 98Mo.
1
132.0–131.3 (m) and 124.5 (s); N(SiMe3)2, 3.2 (s). H,
pyridyl and phenyl, l 8.27 (2H, br, s), 7.44 (6H, br, s)
and 6.91 (20H, m); N(SiMe3)2, 0.17 (36H, s). LRMS
m/z: 616 [(1+1)−Br] and 583 [(1+1)−4CO] for
55Mn and 79Br.
3.12. Preparation of fac-[cis-Cr(CO)4{(NC5H4)-
[(Ph2PNH)C(ꢁNSiMe3)]-4}]2Mn(CO)3Br (11)
A solution of Mn(CO)5Br (0.10 g, 0.34 mmol) in
THF (10 cm3) was added to a stirring solution of 8
(0.19 g, 0.34 mmol) in THF (10 cm3) at 0°C. The
mixture was then allowed to warm to r.t. Upon stirring
overnight, the resulting red solution was pumped to
dryness and washed with diethyl ether (3×2 cm3) to
give a yellow residue, which was redissolved in
dichloromethane (5 cm3) and filtered. A layer of diethyl
ether was then laid over the filtrate. Yellow crystals
were obtained after standing for 2 days. The crystals
were filtered and dried in vacuo. Yield: 0.18 g, 81%,
m.p. 145–147°C (dec.) (Anal. Found: C, 47.9; H, 3.6;
Br, 6.4; N, 6.3. Calc. for C53H48BrCr2MnN6O11-
P2Si2·0.5CH2Cl2: C, 47.8; H, 3.7; Br, 6.0; N, 6.3%). IR
(cm−1, in KBr): 3347w w(NH), 2032s, 2013s, 1951s,
1904vs, 1882vs, 1836vs w(CO). NMR (CD2Cl2):
31P{1H}, l 114.5 (s). 1H, pyridyl, l 8.89 (4H2,6, br,
s) and 7.27 (4H3,5, br, s); phenyl, 7.58–7.51 (20H,
m); NH, 6.75 (2H, br, s); N(SiMe3), 0.12 (18H, br, s).
LRMS m/z: 992 (M−11CO) and 911 (M−11CO−
Br) for 52Cr, 55Mn and 79Br.
3.11. Preparation of cis-
Mo(CO)4{(NC5H4)[(Ph2PNH)C(ꢁNH)]-4} (10)
Compound 7 (0.24 g, 0.4 mmol) and CdCl2 (36 mg,
0.20 mmol) in THF (20 cm3) were stirred at ambient
temperature for 1 day. The resulting brown yellow
solution was filtered and pumped to dryness to give a
yellow residue. The residue was washed with diethyl
ether (2×6 cm3), dissolved in dichloromethane and
filtered. The filtrate was then covered with a layer of
hexane. A yellow precipitate was obtained after stand-
ing for 3 days. After filtering off the yellow residue, the
yellow filtrate was cooled at −5°C for 2 days to give
yellow crystals, which were filtered and dried in vacuo.
Yield: 0.19 g, 50%, m.p. 180–182°C (dec.) (Anal.
Found: C, 51.5; H, 3.1; N, 8.1. Calc. for
C22H16MoN3O4P: C, 51.5; H, 3.1; N, 8.2%). IR (cm−1
in KBr): 3368s w(NH), 2016vs, 1918vs, 1911vs, 1891vs,
1838vs, 1816vs w(CO). NMR (CD2Cl2): 31P{1H}, l 98.8
(s). 1H, phenyl, l 7.57–7.48 (4H, m) and 7.44–7.41
,
Table 2
Summary of crystal data for compounds 1, 3, 6, 9 and 10
1
3
6
9
10
Empirical formula
Formula weight
Crystal system
Space group
C29H33BrMnN2O4PSi2 C22H17BrN2O4PRe C42H48N4O14P2Re2 C59H64Br3Mn3N6O11P2Si4 C22H16MoN3O4P
695.58
670.47
1267.22
1612.00
513.30
Monoclinic
P21/n (no. 4)
10.632(1)
21.139(1)
15.342(1)
Triclinic
Monoclinic
P21/c (no. 14)
12.216(2)
12.167(7)
17.342(5)
Monoclinic
P21/c (no. 14)
16.865(1)
22.989(1)
25.158(1)
Monoclinic
P21/a (no. 14)
11.866(1)
13.902(1)
13.376(1)
(
P1 (no. 2)
,
a (A)
9.976(1)
11.519(1)
12.823(1)
88.20(2)
68.06(2)
81.83(2)
1352.5(3)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
101.3(2)
108.19(2)
98.76(1)
98.41(1)
3
,
U (A )
3378.2(9)
4
2448 (1)
2
9640.2(8)
4
2182.8(3)
4
Z
v (Mo–Ka) (cm−1
Temperature (K)
)
17.29
298
60.61
298
50.71
298
17.59
298
7.07
298
Reflections collected
13 319
11 413
4659 (0.065)
2691
2545 (0.026)
19 026
9662 (0.071)
18 136
4158 (0.042)
Independent reflections 4351 (0.053)
(Rint
)
Observed reflections
2904 [I\1.50|(I)]
0.054
0.052
4147 [I\1.50|(I)]
0.052
0.098
1931 [I\1.50|(I)]
0.041
0.049
5073 [I\1.50|(I)]
0.117
0.136
2534 [I\3.00|(I)]
0.039
0.045
a
R
b
Rw
a R=ꢀꢁꢁFoꢁ−ꢁFcꢁꢁ/ꢀꢁFoꢁ.
b Rw=[ꢀw(ꢁFoꢁ−ꢁFcꢁ)2/ꢀw(Fo)2]1/2
.

W.-Y. Wong et al. / Journal of Organometallic Chemistry 612 (2000) 160–171
171
deposited with the Cambridge Crystallographic Centre
(deposition nos. 143059–143063). Copies of this infor-
mation may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge,
CB2 1EZ, UK (fax: +44-1223-336033; e-mail:
deposit@ccdc.cam.ac.uk or www: http://www.ccdc.cam.
ac.uk).
4. Crystallography
Selected bond lengths and angles of compounds 1, 3,
6, 9 and 10 are given in Table 1. All pertinent crystallo-
graphic data and other experimental details are summa-
rized in Table 2. Intensity data of 1, 3, 9 and 10 were
collected on a MAR research image plate scanner, and
6 on a Rigaku AFC7R diffractometer using graphite-
,
monochromated Mo–Ka radiation (u=0.71073 A). In-
Acknowledgements
tensity data were corrected for Lorentz and
polarization effects. For 1, 3, 9 and 10, absorption
corrections were applied by inter-image scaling whereas
semi-empirical „-scan method was used for 6. The
structures were solved by a combination of direct meth-
ods (SIR-92) [11] and Fourier difference techniques. The
structure solutions were refined by full-matrix least-
squares analysis on F until convergence was reached.
Except for 9, all non-hydrogen atoms were refined
anisotropically. Because of the poorly diffracting nature
of the crystal sample of 9, only the Mn, Br, P and Si
atoms were assigned with anisotropic displacement
parameters to maintain a reasonable data-to-parameter
ratio. Hydrogen atoms on the nitrogen were located
from difference Fourier synthesis using low angle data
(2qB30°) while other hydrogen atoms on the organic
moieties were generated at their ideal positions (CꢀH
W.-K. Wong and W.-Y. Wong thank the Hong
Kong Baptist University and the Hong Kong Research
Grants Council for financial support. W.-T. Wong
thanks the Hong Kong Research Grants Council and
the University of Hong Kong for financial support.
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.