Organometallic building blocks with amino-substituted cyclopentadienyl and boratabenzene ligands for the synthesis of heterometallic complexes and clusters

Article abstract of DOI:10.1039/b602106a

A comparative study of the reactivity of isolobal rhenium and molybdenum carbonylmetallates containing a borole, in [Re(η⁵-C ₄H₄BPh)(CO)₃]^- (2), a boratanaphthalene, in [Mo(η⁵-2,4-MeC₉H ₆BMe)(CO)₃]^- (4a) and [Mo(η⁵-2, 4-MeC₉H₆BNi-Pr₂)(CO)₃]^- (4b), a boratabenzene, in [Mo(η⁵-3,5-Me₂C ₅H₃BNi-Pr₂)(CO)₃]^- (6) or a dimethylaminocyclopentadienyl ligand, in [Mo(η⁵-C ₅H₄NMe₂)(CO)₃]^- (7), toward palladium(ii), gold(i), mercury(ii) and platinum(ii) complexes has allowed an evaluation of the role of these π-bonded ligands on the structures and unprecedented coordination modes observed in the resulting metal-metal bonded, heterometallic complexes. The new metallate 6 was reacted with [AuCl(PPh₃)], and with 1 or 2 equiv. HgCl₂, which afforded the new heterodinuclear complexes [Au{Mo(η⁵-3,5-Me ₂C₅H₃BNi-Pr₂)(CO) ₃}(PPh₃)] (Mo-Au) (10) and [Hg{Mo(η⁵-3,5- Me₂C₅H₃BNi-Pr₂)(CO)₃}Cl] (Hg-Mo) (11) and the heterometallic chain complex [Hg{Mo(η⁵-3,5- Me₂C₅H₃BNi-Pr₂)(CO) ₃}₂] (Mo-Hg-Mo) (12), respectively. Reactions of the new metallate 7 with HgCl₂, trans-[PtCl₂(CNt-Bu)₂] and trans-[PtCl₂(NCPh)₂] yielded the heterodinuclear complex [Hg{Mo(η⁵-C₅H₄NMe ₂)(CO)₃}Cl] (Mo-Hg) (15), the heterotrinuclear chain complexes trans-[Pt{Mo(η⁵-C₅H₄NMe ₂)(CO)₃}₂(CNt-Bu)₂] (Mo-Pt-Mo) (16) and trans-[Pt{Mo(η⁵-C₅H₄NMe ₂)(CO)₃}₂(NCPh)₂] (Mo-Pt-Mo) (17), the mononuclear complex [Mo(η⁵-C₅H₄NMe ₂)(CO)₃Cl] (18), the lozenge-type cluster [Mo ₂Pt₂(η⁵-C₅H₄NMe ₂)₂(CO)₈] (19) and the heterodinuclear complex [Pt{Mo(η⁵-C₅H₄NMe₂)(CO) ₃}(NCPh)Cl](Mo-Pt) (20), respectively. The complexes 11, 16, 17·2THF, 18 and 20 have been structurally characterized by X-ray diffraction and 20 differs from all other compounds in that the dimethylaminocyclopentadienyl ligand forms a bridge between the metals. The Royal Society of Chemistry 2006.

Full text of DOI:10.1039/b602106a

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PAPER
www.rsc.org/dalton | Dalton Transactions
Organometallic building blocks with amino-substituted cyclopentadienyl and
boratabenzene ligands for the synthesis of heterometallic complexes and
clusters†‡§
b
Nicolas Auvray,a Tushar S. Basu Baul,¶ Pierre Braunstein,*a Pierre Croizat,a Ulli Englert,b
Gerhard E. Herberichb and Richard Welterc
Received 13th February 2006, Accepted 6th April 2006
First published as an Advance Article on the web 28th April 2006
DOI: 10.1039/b602106a
A comparative study of the reactivity of isolobal rhenium and molybdenum carbonylmetallates
5
5
containing a borole, in [Re(g -C4H4BPh)(CO)3]− (2), a boratanaphthalene, in [Mo(g -2,4-MeC9H6BMe)-
(CO)3]− (4a) and [Mo(g -2,4-MeC9H6BNi-Pr2)(CO)3]− (4b), a boratabenzene, in [Mo(g -3,5-Me2C5H3-
BNi-Pr2)(CO)3]− (6) or a dimethylaminocyclopentadienyl ligand, in [Mo(g -C5H4NMe2)(CO)3]− (7),
5
5
5
toward palladium(II), gold(I), mercury(II) and platinum(II) complexes has allowed an evaluation of the
role of these p-bonded ligands on the structures and unprecedented coordination modes observed in
the resulting metal–metal bonded, heterometallic complexes. The new metallate 6 was reacted with
[AuCl(PPh3)], and with 1 or 2 equiv. HgCl2, which afforded the new heterodinuclear complexes
5
5
[Au{Mo(g -3,5-Me2C5H3BNi-Pr2)(CO)3}(PPh3)] (Mo–Au) (10) and [Hg{Mo(g -3,5-Me2C5H3-
5
BNi-Pr2)(CO)3}Cl] (Hg–Mo) (11) and the heterometallic chain complex [Hg{Mo(g -3,5-Me2C5H3-
BNi-Pr2)(CO)3}2] (Mo–Hg–Mo) (12), respectively. Reactions of the new metallate 7 with HgCl2,
trans-[PtCl2(CNt-Bu)2] and trans-[PtCl2(NCPh)2] yielded the heterodinuclear complex
5
[Hg{Mo(g -C5H4NMe2)(CO)3}Cl] (Mo–Hg) (15), the heterotrinuclear chain complexes
5
5
trans-[Pt{Mo(g -C5H4NMe2)(CO)3}2(CNt-Bu)2] (Mo–Pt–Mo) (16) and trans-[Pt{Mo(g -C5H4NMe2)-
5
(CO)3}2(NCPh)2] (Mo–Pt–Mo) (17), the mononuclear complex [Mo(g -C5H4NMe2)(CO)3Cl] (18), the
5
lozenge-type cluster [Mo2Pt2(g -C5H4NMe2)2(CO)8] (19) and the heterodinuclear complex
5
[Pt{Mo(g -C5H4NMe2)(CO)3}(NCPh)Cl](Mo–Pt) (20), respectively. The complexes 11, 16, 17·2THF,
18 and 20 have been structurally characterized by X-ray diffraction and 20 differs from all other
compounds in that the dimethylaminocyclopentadienyl ligand forms a bridge between the metals.
Introduction
5
The first borole-containing mixed-metal cluster, [Re2Pd2(g -
C4H4BPh)2(CO)6] (1), has been obtained by reaction of
[PdCl2(COD)], trans-[PdCl2(NCPh)2] or [Pd4(OAc)4(CO)4] with
5
[Re(g -C4H4BPh)(CO)3]− (2).1 It has a planar, triangulated metal
core and its cluster valence electron count (CVE) of only 54
5
contrasts with that of the planar, triangulated clusters [M2Pd2(g -
C5H5)2(CO)6(PEt3)2] (3a–c, M = Cr, Mo, W) which contain 58
CVE.2
This unusual Re2Pd2 cluster displayed a unique bonding mode
of the borole ligand which not only binds to rhenium in the
usual g manner but also to the adjacent palladium via a 2e–
aLaboratoire de Chimie de Coordination, UMR 7177 CNRS, Universite´
Louis Pasteur, 67070, Strasbourg Ce´dex, France. E-mail: braunst@chimie.u-
strasbg.fr
5
3c B–Cipso–Pd system. This led us to extend our studies on
borole-containing carbonylmetallates to the 2-boratanaphthalene
systems 4a,b.3 Their boron-containing six-membered aromatic
ring should behave as a neutral five-electron donor, like the five-
membered Cp ligand and the anionic, five-membered, borole
ligand.
bInstitut fu¨r Anorganische Chemie der Rheinisch-Westfa¨lischen Technischen
Hochschule Aachen, Landoltweg 1, 52074, Aachen, Germany
cLaboratoire DECOMET, UMR 7177 CNRS, Universite´ Louis Pasteur,
67070, Strasbourg Ce´dex, France
† Electronic supplementary information (ESI) available: ORTEP views of
a pair of molecules of 11 (Fig. S1) and views of the packing of molecules
of 11 (Fig. S2). See DOI: 10.1039/b602106a
Consistently, the first metal cluster with a boratanaphthalene
‡ Part of the PhD Thesis of P. C.
5
ligand, [Mo2Pd2(g -2,4-MeC9H6BMe)2(CO)6(PEt3)2] (5), was pre-
§ Dedicated to Prof. P. Zanello on the occasion of his 65th birthday, with
pared from 4a and showed a planar, triangulated metal core with
a centre of symmetry in the middle of the Pd–Pd bond, similar to
that in the Cp derivatives 3.3
our warmest wishes.
¶ Present address: Department of Chemistry, North-Eastern Hill Univer-
sity, NEHU Permanent Campus, Umshing, Shillong 793 022, India.
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The first boratabenzene complex was obtained in 1970
from a cobaltocene8 while Li(TMPA)(C5H5BNMe2) (TMPA =
Me2N(CH2)3NMe2) was, in 1993, the first boratabenzene salt
structurally characterized.6 The presence of a lone pair on the
nitrogen of the dialkyl amino group results in a partial double
bond between the boron and nitrogen atoms.6,7,9,10
Results and discussion
1
Boratabenzene complexes
The 1,2-dimethoxyethane (DME)-solvated lithium salt of the 1-
diisopropylamino-3,5-dimethylboratabenzene tricarbonylmolyb-
5
date [Mo(g -3,5-Me2C5H3BNi-Pr2)(CO)3]− (6) was prepared by
reaction between Li(3,5-Me2C5H3BNi-Pr2)11 and [Mo(CO)6] (see
Experimental section). It was reacted with [AuCl(PPh3)] to
afford the heterodinuclear complex 10, which is analogous to
the known Cp12,13 or substituted Cp derivative C5H4CHO14 and
boratanaphthalene Au–Mo complexes.3
Intrigued by the 2e–3c B–Cipso–Pd bonding in cluster 1, we
wondered whether a stronger donor substituent than the ipso
carbon of the phenyl group of 2, such as an amino group, would be
able to interact with the adjacent metal and confer more stability
to the product. In heterodinuclear Ag–Mo, Au–Mo and Hg–
Mo complexes prepared from the boratanaphthalene tricarbonyl-
molybdate 4b, no interaction was found between the amino group
and the metal adjacent to the molybdenum centre.3 We decided to
compare the reactivity and bonding in heterometallic complexes of
three related tricarbonylmolybdates: the new diisopropylamino-
When Li·6·2DME was reacted with HgCl2 in a 1 : 1 ratio, the
heterodinuclear complex 11 was obtained, of which the structure
was determined by X-ray diffraction. One of the two independent
5
boron-substituted 3,5-dimethylboratabenzene derivative [Mo(g -
3,5-Me2C5H3BNi-Pr2)(CO)3]− (6), the 2-diisopropylamino-4-
5
methyl-2-boratanaphthalene analogue [Mo(g -2,4-Me2C9H6BN-
i-Pr2)(CO)3]− (4b)3 and the new amino-substituted cyclopentadi-
5
enyltricarbonylmolybdate [Mo(g -C5H4NMe2)(CO)3]− (7).
molecules of similar conformation is represented in Fig. 1(a); the
caption provides a comparison of relevant interatomic distances
and angles in both molecules. An ORTEP view of the complete
asymmetric unit is available in Fig. S1 (ESI†). The four-legged
piano stool-type geometry around the molybdenum atom, de-
fined by the three carbonyl groups and the mercury atom, is
Borabenzene 8 does not exist due to a low-lying in plane r*-
type LUMO which is essentially localized at the boron atom.4,5
Therefore stabilization by a Lewis base is necessary and is achieved
in the amino-substituted boratabenzene 9.6,7
5
similar to that observed in [Hg{Mo(g -C5H5)(CO)3}Cl]15,16 and
5
[Mo(g -C5H5)(CO)3Cl].16 The Hg–Mo distance of 2.6904(16) A
˚
˚
[2.6852(15) A in the second molecule] is very similar to that
observed in [Hg{Mo(g -C5H5)(CO)3}Cl] (2.683(1) A).16 The boron
5
˚
˚
˚
atom is situated 0.3244(2) A [0.3322(2) A] out of the mean
plane defined by the carbon atoms of the boratabenzene ring.
Thus, the bonding mode of the heterocycle to the molybdenum
5
6
atom is closer to g than g . The B–N double-bond character is
17
˚
reflected in the distance of 1.406(18) [1.453(17)] A and the sum
of the angles around N is 359.6(12) [360.0(11)]◦. These features
are similar to those encountered in a related Au–Mo complex.3
A torsional orientation of the ring brings the amino group
˚
connected to the boron atom at a N · · · Hg distance of 3.561(10) A
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˚
analog 14, which contains one protonated amino group (i.e. one
B-amino and one B-ammonio substituent), showed a different,
endo-type orientation of the 2-boratanaphthalene ligands, how-
[3.584(10) A], which is too long to represent a significant bonding
interaction. The Cl–Hg–Mo angle is 177.82(11)◦ [173.69(12)◦] and
intermolecular interactions between the mercury and the chlorine
atoms of two proximate molecules in the unit cell result in Hg · · · Cl
ever with no significant interaction between the amino-N and Ag
3
˚
˚
atoms (4.617(2) A).
separations of 3.483(5) and 3.430(5) A (Fig. 1(b)). A view of the
solid-state packing is shown in Fig. S2 (ESI†).
With the amino-substituted boratabenzene or boratanaphtha-
lene systems described so far, no bonding interaction between the
nitrogen atom and a metal centre was observed. We have then
turned our attention to amino-substituted Cp derivatives, related
to the phenylborole ligand present in cluster 1.
2
Amino-Cp complexes
5
We first prepared the new metallate Li[Mo(g -C5H4NMe2)(CO)3]·
2DME (Li·7·2DME) by reaction of Li(C5H4NMe2)18 with
[Mo(CO)6] in refluxing DME, by analogy with the synthesis of
Na(C5H5)·DME (see Experimental section).19 Its reaction with
HgCl2 in a 1 : 1 ratio was carried out with the objective to struc-
5
turally characterize the expected Mo–Hg–Cl product [Hg{Mo(g -
C5H4NMe2)(CO)3}Cl] (15). However, the crystals obtained were
not of good enough quality to allow a complete structural resolu-
Fig. 1 (a) ORTEP view of one of two independent molecules in the
structure 11 with the atom-numbering scheme. Displacement ellipsoids
enclose 50% of the electron density. Selected bond distances (A) and angles
˚
tion but the N · · · Hg separation found of ca. 3.5 A is analogous
to that observed in 11 (see Experimental section).
˚
The synthesis of linear Mo–Pt–Mo complexes was envisaged
in order to answer the question of a possible coordination of
the Cp-bound amino group to platinum. The reaction between
Li·7·2DME and trans-[PtCl2(CNt-Bu)2] in a 2 : 1 ratio was
performed in THF at −40 ◦C. It afforded the expected trinuclear
(◦) [values for the second molecule in square brackets]: Hg(1)–Mo(1)
2.6904(16) [2.6852(15)], Hg(1)–Cl(1) 2.404(4) [2.397(4)], Mo(1)–C(1)
1.995(14) [2.032(15)], Mo(1)–C(2) 2.013(15) [1.989(15)], Mo(1)–C(3)
1.944(14) [1.972(14)], C(1)–O(1) 1.141(14) [1.121(15)], C(2)–O(2)
1.130(15) [1.150(15)], C(3)–O(3) 1.169(15) [1.154(15)], B(1)–N(1) 1.406(18)
[1.453(17)]; Mo(1)–Hg(1)–Cl(1) 177.84(11) [173.72(11)], Mo(1)–C(1)–O(1)
175.9(13) [178.1(14)], Mo(1)–C(2)–O(2) 171.8(14) [174.5(14)], Mo(1)–
C(3)–O(3) 179.4(14) [176.3(14)], C(1)–Mo(1)–Hg(1) 79.9(4) [75.0(4)],
Hg(1)–Mo(1)–C(2) 72.0(4) [74.5(4)], C(2)–Mo(1)–C(3) 77.9(6) [77.8(6)],
C(3)–Mo(1)–C(1) 79.2(6) [77.9(6)], C(1)–Mo–C(2) 104.3(6) [109.2(6)],
B(1)–N(1)–C(9) 125.1(11) [123.2(11)], B(1)–N(1)–C(10) 119.8(11)
[123.4(11)], C(9)–N(1)–C(10) 114.7(10) [113.4(10)]. (b) View of the inter-
molecular interactions between molecules of 11. Hg · · · Cl = 3.483(5) and
5
complex trans-[Pt{Mo(g -C5H4NMe2)(CO)3}2(CNt-Bu)2] (16) as
an orange compound, analogous to the parent Cp derivative.20 Its
˚
3.430(5) A.
When Li·6·2DME and HgCl2 were reacted in a 2 : 1 ratio, the
expected heterotrinuclear complex 12 was obtained. In the re-
lated centrosymmetric N-diisopropylamino-2-boratanaphthalene
derivative 13 an exo-type orientation of the amino groups was
established by X-ray diffraction.3 In contrast, the neutral silver
structure determination by X-ray diffraction showed that the Pt
atom lies on an inversion centre. An ORTEP view is shown in Fig. 2
with the main distances and angles. The four-legged piano stool
type geometry around the molybdenum atoms, defined by the three
2952 | Dalton Trans., 2006, 2950–2958
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With the hope of generating a 2e–3c CipsoCp–N–Pt inter-
action or a 2e–2c N–Pt bond, we reacted Li·7·2DME with
trans-[PtCl2(NCPh)2], which contains labile PhCN ligands, in
a manner similar to that described for trans-[PtCl2(CNt-Bu)2].
The major compound obtained in this reaction was trans-
5
[Pt{Mo(g -C5H4NMe2)(CO)3}2(NCPh)2] (Mo–Pt–Mo) (17). The
X-ray diffraction analysis of 17·2THF established that the Pt atom
lies on an inversion centre and the resulting linear arrangement of
the metals is also found in related Cp complexes.22,23 There is no
CipsoCp–N–Pt interaction. An ORTEP view is shown in Fig. 3 with
the main distances and angles. Despite its much higher lability
compared to t-BuNC, the benzonitrile ligand is obviously not
displaced by the NMe2 donor group.
Fig. 2 ORTEP view of the structure 16 with the atom-numbering scheme.
Operators for generating equivalent, primed atoms (−x, −y, −z). Displace-
ment ellipsoids enclose 50% of the electron density. Selected bond distances
◦
˚
(A) and angles ( ): Pt–Mo 2.868(1), Pt–C(11) 1.958(6), Mo–C(1) 1.976(6),
Mo–C(2) 1.983(6), Mo–C(3) 1.953(6), C(1)–O(1) 1.156(7), C(2)–O(2)
1.156(7), C(3)–O(3) 1.150(7), C(8)–N(2) 1.376(6); Mo–C(1)–O(1) 173.4(5),
Mo–C(2)–O(2) 172.4(5), Mo–C(3)–O(3) 179.7(6), Mo–Pt–C(11)’ 87.6(1),
Mo–Pt–C(11) 92.4 (2), Pt–Mo–C(1) 65.5(2), C(1)–Mo–C(3) 81.0(3),
C(3)–Mo–C(2) 82.2(3), C(2)–Mo–Pt 61.8(2), C(2)–Mo–C(1) 108.8(2),
C(8)–N(2)–C(9) 115.6(5), C(8)–N(2)–C(10) 116.1(5), C(9)–N(2)–C(10)
115.8(5).
carbonyl groups and the platinum atom, is similar to that observed
5
in 11 and [Mo(g -C5H5)(CO)3Cl].16 However, in contrast to 11, the
crystal structure of 16 reveals an exo-type orientation of the amino
groups, most probably because of the presence of the bulky t-
BuNC ligands coordinated to the platinum. The carbonyl groups
5
on each Mo(g -C5H4NMe2)(CO)3 fragment are quasi terminal,
the Mo–C(1)–O(1), Mo–C(2)–O(2) and Mo–C(3)–O(3) angles
being of 173.4(5), 172.4(5) and 179.7(6)◦, respectively. The C(1)–Pt
Fig.
3
ORTEP view of the structure 17 in 17·2THF with the
atom-numbering scheme. Operators for generating equivalent, primed
atoms (−x, −y, 1 − z). Displacement ellipsoids enclose 50% of the electron
˚
˚
(2.725(5) A) and C(2)–Pt (2.604(7) A) separations appear to be too
long to represent a significant bonding interaction. However, when
considering the structural asymmetry parameter a = (d2 − d1)/d2
(Scheme 1) often used to characterize the bonding situation of
carbonyl ligands,21 its value for the ligands C(1)O(1) and C(2)O(2)
of 0.38 and 0.31, respectively, could qualify them for being semi-
bridging.
◦
˚
density. Selected bond distances (A) and angles ( ): Pt–Mo 2.854(3),
Pt–N(1) 1.942(7), Mo–C(1) 1.98 (1), Mo–C(2) 1.97(1), Mo–C(3) 1.93(1),
C(1)–O(1) 1.16(1), C(2)–O(2) 1.16(1), C(3)–O(3) 1.18(1), C(8)–N(2)
1.36(1); Mo–C(1)–O(1) 172.0(9), Mo–C(2)–O(2) 170.1(8), Mo–C(3)–O(3)
177(1), Mo–Pt–N(1) 92.9(2), Mo–Pt–N(1)’ 87.1(2), Pt–Mo–C(1) 62.3(3),
C(1)–Mo–C(3) 85.3(4), C(3)–Mo–C(2) 82.0(4), C(2)–Mo–Pt 59.4(3),
C(2)–Mo–C(1) 113.4(3), C(8)–N(2)–C(9) 119.9(9), C(8)–N(2)–C(10)
116.7(9), C(9)–N(2)–C(10) 111.9(9).
The crystal structure of 17 is very similar to that of 16 and
˚
the Mo–Pt distances are almost the same (2.854(3) A for 17,
˚
2.868(1) A for 16). The orientation of the amino-Cp ring with
respect to the platinum coordination plane is 85.8(4)◦. The sum
of the angles around the nitrogen atom of the NMe2 groups N(2)
Scheme 1 a = (d2 − d1)/d1; 0.1 ≤ a ≤ 0.6: semi bridging carbonyl; a ≤
0.1: bridging carbonyl; a ≥ 0.6: terminal carbonyl.
◦
5
is 349(3) . The carbonyl groups of the Mo(g -C5H4NMe2)(CO)3
fragment are almost terminal, with Mo–C(1)–O(1), Mo–C(2)–
O(2) and Mo–C(3)–O(3) angles very similar to their analogues
The platinum coordination plane and the C5 ring are orthogonal
to each other (90.0(2)◦). In contrast to the situation in 11, the
nitrogen atoms connected to the Cp rings are in a pyramidal
environment (sum of the angles around N of 348(2)◦), and this
is consistent with a pure r-bond between the nitrogen and the Cp
ring.
˚
in 16. The Pt–C(1) and Pt–C(2) distances in 17 (2.61(1) A and
˚
2.509(9) A) are slightly shorter than in 16 (2.725(5) and 2.604(7)
˚
A, respectively). Considering the values of the parameter a = (d2 −
d1)/d2 (Scheme 1) for the ligands C(1)O(1) and C(2)O(2) of 0.32
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and 0.27, respectively, these ligands may also be considered as
semi-bridging.21,24–26
Fig. 5 with the main distances and angles. The Pt–Mo distance
˚
˚
of 2.748(1) A is slighly shorter than in 16 (2.868(1) A) and 17
˚
˚
Three other compounds which are soluble in diethyl ether
were also obtained in low yields from the reaction leading to
17. The most soluble of them, even in pentane, was character-
(2.854(3) A). The Pt–N(2) distance is 2.079(5) A and the non-
planar environment of this nitrogen atom (sum of the angles
around N(2) of 332(2)◦), confirms its coordination to platinum.
This results in a lengthening of the N(2)–C(8) bond (1.455(9)
5
ized by X-ray diffraction as the mononuclear complex [Mo(g -
˚
˚
C5H4NMe2)(CO)3Cl] (18).An ORTEP view is shown in Fig. 4 with
the main distances and angles. This four legged piano stool struc-
ture and the bond distances and angles are very similar to those
A) compared to its value in 17 (1.36(1) A). Although only a
unique crystal of this complex was obtained, despite attempts to
prepare or isolate it in larger quantities, which precluded recording
of spectroscopic data, we believe that its interesting structure
warrants a mention since this appears to be the first example
of such an intramolecular bridging coordination mode for an
amino-cyclopentadienyl ligand. It is however related to that in
phosphino-cyclopentadienyl heterometallic systems.27,28
5
in [Mo(g -C5H5)(CO)3Cl].16 The nitrogen atom is in an almost
perfectly planar environment (the sum of the angles around N is
359.0(9)◦). This complex obviously results from a redox reaction.
5
The red–brown, 58 CVE cluster [Mo2Pt2(g -C5H4NMe2)2(CO)8]
(19) was also isolated by fractional crystallization, and its crystal
structure showing a metal core similar to that in the clusters 3b and
5
in [Mo2Pt2(g -C5H5)2(CO)6(PEt3)2]22 will be detailed elsewhere.
Fig. 5 ORTEP view of the structure 20 with the atom-numbering scheme.
Displacement ellipsoids enclose 5◦0% of the electron density. Selected
˚
bond distances (A) and angles ( ): Pt–Mo 2.748(1), Pt–Cl 2.401(2),
Pt–N(1) 1.956(6), Pt–N(2) 2.079(5), Mo–C(1) 1.967(8), Mo–C(2) 1.983(7),
Mo–C(3) 1.995(8), C(1)–O(1) 1.159(9), C(2)–O(2) 1.157(8), C(3)–O(3)
1.155(8), C(8)–N(2) 1.455(9); Mo–Pt–N(1) 96.9(2), Mo–Pt–N(2) 79.8(2),
N(2)–Pt–Cl 93.4(2), N(1)–Pt–Cl 89.8(2), Mo–C(1)–O(1) 176.2(7),
Mo–C(2)–O(2) 175.1(6), Mo–C(3)–O(3) 178.6(7), Pt–N(2)–C(9) 109.9(4),
Pt–N(2)–C(10) 112.1(4), Pt–N(2)–C(8) 102.6(4), Pt–Mo–C(2) 70.3(2),
C(2)–Mo–C(3) 81.2(3), C(3)–Mo–C(1) 83.1(3), C(1)–Mo–Pt 72.8(2),
C(1)–Mo–C(2) 101.4(3), C(8)–N(2)–C(9) 112.3(5), C(8)–N(2)–C(10)
112.8(5), C(9)–N(2)–C(10) 107.3(6).
Fig. 4 ORTEP view of the structure 18 with the atom-numbering scheme.
The fact that this dinuclear complex could be isolated indicates
Displacement ellipsoids enclose◦50% of the electron density. Selected
that substitution of the second chloride leading to 17 is slow
˚
bond distances (A) and angles ( ): Mo–Cl 2.518(1), Mo–C(1) 1.995(3),
5
enough to allow the g -C5H4-bound NMe2 group to irreversibly
Mo–C(3) 1.987(3), Mo–C(2) 2.030(3), C(1)–O(1) 1.142(4), C(3)–O(3)
1.138(4), C(2)–O(2) 1.138(3), C(8)–N 1.327(4); Mo–C(1)–O(1) 174.5(2),
Mo–C(3)–O(3) 177.4(3), Mo–C(2)–O(2) 176.1(3), Cl–Mo–C(1) 80.6(1),
C(1)–Mo–C(3) 79.3(1), C(2)–Mo–C(3) 79.4(1), C(2)–Mo–Cl 77.83(9),
C(1)–Mo–C(2) 111.1(1), C(8)–N–C(9) 120.4(3), C(8)–N–C(10) 120.5(3),
C(9)–N–C(10) 118.1(3).
displace one of the Pt-bound benzonitrile ligands (Scheme 2).
Because of the too small quantity of complex 20 isolated, we
could not yet verify that it would react with another equivalent of
7 to give, logically, a Mo–Pt–Mo chain complex with two bridging
amino-cyclopentadienyl ligands, similar to a Mo–Pd–Mo complex
containing two bridging phosphino-cyclopentadienyl ligands.28
From a structural view point, it appeared interesting to compare
the coordination geometry about the Mo centre in the different
complexes structurally analyzed in this work by using as param-
eters the angles between the mean plane formed by the carbon
atoms of the p-ligand and the plane defined by the carbon atoms
A more unexpected molecule was the pale orange heterodimetal-
5
lic complex [Pt{Mo(g -C5H4NMe2)(CO)3}(NCPh)Cl] (Mo–Pt)
(20) which was shown by X-ray diffraction to display a bonding
interaction between the amino donor function of the cyclopenta-
dienyl ring and the platinum centre. An ORTEP view is shown in
2954 | Dalton Trans., 2006, 2950–2958
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a four-legged piano stool structure. A typical, regular three-legged
piano-stool structure is characte◦rized by a very small b angle, as
5
in [Mo(g -C5H5)(CO)3]− (1.95(1) ).30
In complex 20, the angle c is 11.56(2)◦ and the geometry about
the Mo atom becomes better described as a three-legged piano-
stool with the X ligand (here Pt) capping a face of the MoC3
tetrahedron. In this case, it is the b angle which becomes very small
(1.19(2)◦). Consistently, the Mo–X distance increases compared to
that in 18.
However, since the orientation of the mean plane defined by
C(1), C(2), C(3) and the fourth leg X of the piano stool with
respect to the p-bonded ring also depends on the difference
between the Mo–X and Mo–CO distances, the parameter c may
not always be ideal for making valid comparisons. Therefore, we
also provide in Table 1 a comparison of the angles between the
trans ligands C(1)–Mo–C(2) and C(3)–Mo–X. We also compare
the angles between the Mo–CO or Mo–X bonds and the axis
passing through the molybdenum and the p-bonded ring centroid.
These values confirm that the most regular four-legged piano
stool structure is that of 16. In the case of 20 the three centroid–
Mo–C angles are almost equal, whereas the centroid–Mo–X (Pt
in this case) is much smaller, consistent with the description
of a three-legged piano stool structure with one MoC3 face
capped by X. For 11, 17 and 18, these parameters indicate
an intermediate situation and irregular four-legged piano stool
structures.16
Conclusion
Scheme 2 Suggested mechanism for the formation of complexes 17 and
20.
In this work, we have examined the reactivity of a set of isolobal
organometallic building blocks toward metal complexes with a
d8 (Pd(II), Pt(II)) or d10 (Au(I), Hg(II)) electronic configuration
with the aim to synthesize metal–metal bonded heterometallic
complexes. We have shown that the tricarbonylmolybdates 4a,b,
6 and 7, which contain boratanaphthalene, boratabenzene and
cyclopentadienyl p-bonded ligands, respectively, all have a metal-
centred nucleophilicity which explains the formation of the metal–
metal bonded products. The amino function bonded to the boron
atom in 4b and 6 did not participate in direct bonding to a
metal adjacent to the Mo atom. In contrast, the amino-substituted
cyclopentadienyl ligand in 7 can support a metal–metal bond, as
observed in the Mo–Pt complex 20.
of the three carbonyl ligands (angle b) and that between the
mean plane formed by the carbon atoms of the p-ligand and the
mean plane defined by these three carbon atoms and the fourth
substituent X (angle c ) (Table 1).
A typical four-legged piano-stool structure is characterized by
very small values of the c angle. As an example, this is the case
5
in the very regular four-legged piano-stool structure of [Ta(g -
C5H5)(CO)4], with a c angle of 1.32(1)◦.29 In the case of 18, in
which the Mo–X and Mo–CO distances are much closer than in
the other complexes studied, the low value of c is consistent with
5
Table 1 Comparison of the structural parameters in complexes of the type [Mo(g -C5H5)(CO)3X]
Angle/◦
[TaCp(CO)4]
[MoCp(CO)3]−
11 (mol. 1)
11 (mol. 2)
16
17·2THF
18
19.89(1)
7.74(1)
111.1(1)
141.6(1)
122.07(8)
126.76(9)
111.1(1)
107.3(2)
20
ba
—
1.95(1)
—
—
12.5(8)
1.1(7)
6.2(8)
1.2(7)
1.17(2)
6.20(2)
4.34(2)
9.41(2)
1.19(2)
c b
1.32(1)
117.4(3)
117.4(3)
122.0(2)
122.0(2)
120.6(2)
120.6(2)
11.56(2)
101.4(3)
137.5(2)
126.8(2)
124.8(2)
125.1(2)
97.19(3)
C(1)–Mo–C(2)
C(3)–Mo–X
Centroid–Mo–C(1)
Centroid–Mo–C(2)
Centroid–Mo–C(3)
Centroid–Mo–X
104.2(6)
137.5(5)
126.3(5)
128.5(5)
117.3(5)
104.95(3)
109.2(6)
131.7(4)
125.3(5)
124.6(5)
120.0(5)
108.26(4)
108.8(2)
115.8(2)
124.0(2)
124.5(2)
119.5(2)
124.74(2)
113.4(3)
105.7(3)
120.1(3)
121.4(3)
122.9(3)
131.43(4)
—
127.24(1)
127.63(1)
125.01(1)
—
a b: angle between the mean plane defined by the carbon atoms of the p-bonded ring (Cp or boratabenzene) and the plane defined by the C(1), C(2), C(3)
atoms. b c : angle between the mean plane defined by the carbon atoms of the p-bonded ring (Cp or boratabenzene) and the mean plane defined by C(1),
C(2), C(3) and the fourth leg X of the piano stool (X = Hg, Pt or Cl).
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Synthesis of Li[Mo(g5-C5H4NMe2)(CO)3]·2DME (Li·7·2D-
ME). Solid [Mo(CO)6] (2.87 g, 10.86 mmol) was added to a
solution of Li(C5H4NMe2) (1.25 g, 10.86 mmol) in 100 mL
dimethoxyethane (DME). The mixture was refluxed for 4 h with
constant stirring. The disappearance of [Mo(CO)6] was followed
by IR spectroscopy. After concentration of the solution and
precipitation with pentane (200 mL), the compound Li·7·2DME
was isolated, washed with pentane (3 × 50 mL) and dried in vacuo
to give a brown oil. The o◦il is very sensitive toward oxidation
and should be kept at −30 C. There are two moles of DME of
Experimental
General procedures
Reactions were carried out under an atmosphere of nitrogen by
means of conventional Schlenk techniques. Hexane was distilled
from sodium/potassium alloy, toluene from sodium, diethyl ether
from sodium/benzophenone, and dichloromethane from calcium
dihydride. When indicated, melting points were determined in
sealed capillaries on a Bu¨chi 510 melting point apparatus and are
uncorrected. Elemental analyses were performed by Analystische
Laboratorien, Prof. Dr. H. Malissa and G. Reuter GmbH, D-
51789 Lindlar, Germany and by the “Service de Microanalyses”,
Universite´ Louis Pasteur, Strasbourg.
NMR spectra were recorded on a Varian Unity 500 (1H,
500 MHz; 13C, 125.7 MHz; 11B, 160.4 MHz; 31P, 202.4 MHz),
a Varian VXR 300 or Bruker Avance 300 (1H, 300 MHz;
13C, 75.47 MHz; 31P, 121.49 MHz) or a Varian Mercury 200
(1H, 200 MHz) spectrometer. Chemical shifts (in ppm) were
measured at ambient temperature and are referenced to internal
TMS for 1H and 13C and to external BF3·OEt2 for 11B, and
external H3PO4 (84%) for 31P, with downfield shifts reported
as positive. The spectra were measured at 298 K. Deuterated
solvents for NMR spectroscopy were degassed, dried and stored
1
solvation per mole of anion, this was determined by H NMR
spectroscopy. Yield 4.45 g, 86%.
Data for Li·7·2DME. 1H NMR ((CD3)2CO): AAꢀXXꢀ system
d 4.76 and 4.45 (2 pseudo-t, 8H, Cp), 3.48 (s, 8H, CH2, DME), 3.30
(s, 12H, CH3, DME), 2.34 (s, 6H, N(CH3)2). IR (THF): m(CO):
1898s, 1799vs, 1773sh, 1709s cm−1.
Synthesis of [Au{Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3}(PPh3)]
(Mo–Au) (10). A mixture of [AuCl(PPh3)] (0.60 g, 1.21 mmol)
and Li·6·2DME (0.70 g, 1.23 mmol) in toluene (30 mL) was stirred
for 2 h. The reaction mixture was then filtered through a frit
covered with silica (9 cm layer). Concentration of the filtrate gave a
viscous residue which was triturated with pentane to form a yellow
suspension. The yellow solid was collected on a frit, washed with
pentane (2 × 5 mL) and recrystallized from toluene to afford 10
(0.89 g, 87%); mp 171–172 ◦C.
˚
over molecular sieves (4 A Merck). Assignments are based
on APT and DEPT spectra and 1H, 1H-COSY and 1H, 13C-
HMQC experiments. IR spectra were recorded in the region
4000–400 cm−1 on a Nicolet Avatar 360 FT IR spectrometer or a
IFS66 Bruker spectrometer. The following compounds were syn-
thesized according to literature procedures: Li(3,5-Me2C5H3BNi-
Pr2),11 Li(C5H4NMe2),18 [AuCl(PPh3)],31 trans-[PtCl2(CNt-Bu)2]20
and trans-[PtCl2(NCPh)2].19,32 The compound C5H5NMe2 was
obtained by reaction of TsONMe233 with Na(C5H5)·DME,34 which
is a slight modification of the literature procedure in which
methylsulfonyl chloride was reacted with Li(C5H5).18
Data for 10. Anal. Calc. for C34H38AuBMoNO3P: C, 48.42;
1
H, 4.54; N, 1.66. Found: C, 48.76; H, 4.25; N, 1.98%. H NMR
(C6D6): d 5.08 (br s, couplings not resolved, 1H, H-4), 4.58 (br s,
coupling not resolved, 2H, H-2/6), 2.02 (s, 6H, Me-3/5); Ni-Pr2:
3.57 (sept, 2H, NCH), 1.25 (d, 12H, Me, 3J = 6.8 Hz); PPh3: 7.5
1
(m, 6 Ho), 7.0 (m, 6 Hm + 3 Hp). 13C{ H} NMR (C6D6): d 228.4
(CO), 127.1 (C-3/5), 86.4 (br, C-2/6), 84.2 (C-4), 25.7 (Me-3/5);
Ni-Pr2: 46.2 (NCH), 22.7 (Me); PPh3: 134.3 (d, JPC = 15 Hz, Co),
131.3 (d, JPC = 11 Hz, Cm), 131.1 (d, JPC = 51 Hz, Ci), 129.0 (d,
JPC = 2 Hz, Cp). 11B NMR (C6D6): d 24.7. IR (KBr): m(CO): 1952s,
1862s, 1828s cm−1.
Synthesis of Li[Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3]·2 DME
(Li·6·2DME). Solid [Mo(CO)6] (3.98 g, 15.1 mmol) was added to
a warm solution of Li(3,5-Me2C5H3BNi-Pr2) (3.18 g, 15.1 mmol)
in DME (100 mL). The reaction mixture was stirred and heated
to reflux temperature. It slowly turned yellow. After 24 h it was
filtered through a frit covered with silica (4.5 cm layer) and further
eluted with DME (3 × 10 mL). The volatiles were removed from
the filtrate in vacuum. Pentane (50 mL) was then added to the
residue. After stirring the mixture for 1 h the solid product was
collected by filtration, washed with pentane (3 × 50 mL), and dried
under vacuum to give Li·6·2DME (6.70 g, 78%) as a pale yellow
solid; mp 102–103 ◦C, insoluble in pentane, soluble in toluene,
DME and THF.
Synthesis of [Hg{Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3}Cl] (Hg–
Mo) (11). Solid HgCl2 (0.50 g, 1.84 mmol) was added to a
suspension of Li·6·2DME (0.95 g, 1.66 mmol) in toluene (40 mL).
After the mixture was stirred for 2 h, the resulting dark yellow
suspension was filtered through a frit covered with silica (4 cm
layer) and further eluted with toluene (2 × 20 mL) in order to
achieve complete extraction. After removal of the volatiles the
yellow residue was triturated and washed with pentane (5 × 3 mL).
It was then recrystallized from a small amount of toluene at
−30 ◦C to give, after drying under vacuum, 11 (0.88 g, 85%) as a
bright yellow crystalline solid; mp 167–168 ◦C (decomp.), soluble
in toluene and insoluble in pentane.
Data for Li·6·2DME. Anal. Calc. for C24H43BLiMoNO7: C,
1
50.46; H, 7.59; N, 2.45. Found: C, 50.56; H, 7.10; N, 2.56%. H
Anal. Calc. for C16H23BClHgMoNO3: C, 30.99; H, 3.74; N, 2.26.
Found: C, 30.89; H, 3.71; N, 2.18%. 1H NMR (C6D6): d 4.84 (br s,
NMR (THF-d8): d 4.69 (t, 1H, H-4), 3.81 (d, 2H, H-2/6, 4J24 = 1.5
Hz), 2.02 (s, 6H, Me-3/5); Ni-Pr2: 3.52 (sept, 2H, NCH), 1.17 (d,
12H, Me, 3J = 6.8 Hz; DME: 3.43 (s, 8H, CH2), 3.27 (s, 12H, Me).
4
couplings not resolved, 1H, H-4), 4.18 (d, 2H, H-2/6, J24 = 1.2
Hz), 1.39 (s, 6H, Me-3/5); Ni-Pr2: 3.29 (sept, 2H, NCH), 1.18 and
1
3
1
13C{ H} NMR (THF-d8): d 232.9 (CO), 125.1 (C-3/5), 84.3 (br,
1.11 (2d, 2 × 6 H, J = 6.8 Hz). 13C{ H} NMR (C6D6): d 221.7
(CO), 123.3 (C-3/5), 85.9 (C-4), 84.7 (br, C-2/6), 23.7 (3-/5-Me);
Ni-Pr2: 46.5 (NCH), 22.5 and 21.6 (Me). 11B NMR (C6D6): d 24.3.
IR (KBr): m(CO): 2020s, 1940s, 1922s cm−1.
C-2/6), 81.0 (C-4), 25.7 (Me-3/5); Ni-Pr2: 46.0 (NCH), 22.8 (Me);
DME: 72.6 (OCH2), 58.7 (OMe). 11B NMR (THF-d8): d 24.3. IR
(KBr): m(CO): 1916s, 1793s, 1747s cm−1.
2956 | Dalton Trans., 2006, 2950–2958
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0.56 mmol) in THF (20 mL) at −40 ◦C. Under constant stirring,
the temperature was slowly raised to reach 20 ◦C in 8 h. The
solution was filtered through Celite and most of the solvent was
evaporated under reduced pressure. After addition of pentane and
storing the mixture overnight in a freezer, the product precipitated
as an orange powder. It was washed with water and ethanol and
dried in vacuum. Orange-red crystals of 16 were obtained after
recrystallization from THF–pentane. Yield: 0.18 g, 69%.
Synthesis of [Hg{Mo(g5-3,5-Me2C5H3BNi-Pr2)(CO)3}2] (Mo–
Hg–Mo) (12). A suspension of HgCl2 (0.22 g, 0.83 mmol) and
Li·6·2DME (0.96 g, 1.68 mmol) in toluene (80 mL) was stirred for
2 h. The reaction mixture was then filtered through a frit covered
with silica (9 cm layer), and all volatiles were removed from the
filtrate. The residue was washed with pentane and recrystallized
from toluene to produce 12 (0.70 g, 87%) as a bright yellow solid;
mp 260–262 ◦C.
Data for 16. Anal. Calc. for C30H38Mo2N4O6Pt: C, 38.43; H,
4.09; N, 5.98. Found: C, 37.86; H, 3.92; N, 5.67%. 1H NMR (C6D6):
AAꢀXXꢀ system d 5.01 and 4.57 (2 pseudo-t, 8H, Cp), 2.24 (s, 12H,
Data for 12. Anal. Calc. for C32H46B2HgMo2N2O6: C, 39.67;
H, 4.79; N, 2.89. Found: C, 39.88; H, 4.91; N, 2.98%. H NMR
1
(C6D6): d 5.17 (br s, couplings not resolved), 1H, H-4), 4.31 (d, 2H,
H-2/6, 4J24 = 1.2 Hz), 1.83 (s, 6H, Me-3/5); Ni-Pr2: 3.47 (sept, 2H,
1
NMe2), 1.23 (s, 18H, CH3, t-Bu). 13C{ H} NMR (C6D6): d 242.3
3
1
NCH), 1.19 (d, 12H, Me, J = 6.8 Hz). 13C{ H} NMR (C6D6):
d 226.1 (CO), 126.2 (C-3/5), 87.3 (br, C-2/6), 85. 1 (C-4), 25.3
(Me-3/5); N–iPr2: 46.2 (NCH), 22.5 (br, Me). 11B NMR (C6D6): d
24.7. IR (KBr): m(CO): 1962s, 1899br s cm−1.
(CO), 84.7 and 74.6 (8C, CH from Cp), 40.9 (N(CH3)2), 29.5
(CH3 from t-Bu). IR (KBr): m(NC): 2168s, m(CO): 1907vs, 1850vs
br, 1830vs cm−1.
Synthesis of trans-[Pt{Mo(g5-C5H4NMe2)(CO)3}2(NCPh)2]
(Mo–Pt–Mo) (17). Solid trans-[PtCl2(NCPh)2] (0.069 g,
0.15 mmol) was added to a stirred solution of Li·7·2DME (0.14 g,
0.29 mmol) in toluene (5 mL) at −40 ◦C. The reaction mixture
was slowly brought to 20 ◦C in 8 h with constant stirring.
The solution was filtered and the red–brown solid obtained
was washed with toluene, water to remove the LiCl salt, and
ethanol, affording the red–brown complex 17. Owing to its
poor solubility, no NMR data were obtained. Recrystallization
from THF–pentane afforded orange crystals which readily des-
olvated in air. The crystal structure resolution indeed revealed
the presence of two molecules of THF per mole of 17. Yield:
0.08 g, 55%. The solution obtained after filtration of the toluene
suspension was evaporated under reduced pressure. Extraction
Synthesis of [Hg{Mo(g5-C5H4NMe2)(CO)3}Cl] (15). Solid
HgCl2 (0.05 g, 0.17 mmol) was added to a suspension of
Li·7·2DME (0.082 g, 0.17 mmol) in toluene (20 mL). After the
mixture was stirred for 4 h, the resulting pale yellow suspension
was filtered. After removal of the volatiles under reduced pressure,
the pale yellow residue was washed with pentane (5 × 3 mL). It
was then recrystallized by layering a toluene solution with pentane
and storing at −30 ◦C. Complex 15 was isolated as pale yellow
crystals. Their quality was only sufficient for a preliminary X-ray
diffraction study. Yield: 0.035 g, 39%. IR (THF): m(CO): 2001vs,
1
1967vs, 1915vs cm−1. H NMR (CDCl3): AAꢀXXꢀ system d 5.10
and 4.60 (2 pseudo-t, 8H, Cp), 2.59 (s, 12H, NMe2).
Synthesis of trans-[Pt{Mo(g5-C5H4NMe2)(CO)3}2(CNt-Bu)2]
(Mo–Pt–Mo) (16). Solid trans-[PtCl2(CNt-Bu)2] (0.12 g,
0.28 mmol) was added to a stirred solution of Li·7·2DME (0.26 g,
of the solid with pentane afforded the soluble complex [Mo(g -
5
C5H4NMe2)(CO)3Cl] (18), which was characterized by X-ray
crystallography. [IR (KBr): m(CO): 2031vs, 1969vs, 1923vs cm−1].
Table 2 Crystallographic data, data collection parameters and refinement results
11
16
17·2THF
18
20
Formula
Mr
C16H23BClHgMoNO3
620.14
Monoclinic
C30H38Mo2N4O6Pt
937.61
Monoclinic
C42H46Mo2N4O8Pt
1121.80
Triclinic
¯
P1
8.518(5)
11.117(5)
12.785(5)
94.91(5)
109.36(5)
107.20(5)
1068.3(9)
1
C10H10ClMoNO3
323.58
Monoclinic
C17H15ClMoN2O3Pt
621.79
Triclinic
¯
P1
9.477(1)
9.637(1)
10.430(1)
82.48(5)
83.48(5)
73.05(5)
900.5(2)
2
Crystal system
Space group
P21/c
P21/c
P21/n
˚
a/A
15.0320(12)
14.026(3)
19.843(2)
90.00
107.908(8)
90.00
8.530(5)
17.111(5)
12.321(5)
90.00
108.30(5)
90.00
8.8250(3)
10.7520(3)
12.8080(4)
90.00
99.38(5)
90.00
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
V/A
Z
3
˚
3981.0(10)
8
1707.3(13)
2
1199.07(6)
4
Crystal size/mm
Colour
0.32 × 0.07 × 0.04
0.10 × 0.10 × 0.10
Orange
1.824
0.10 × 0.10 × 0.10
Orange
1.744
0.10 × 0.10 × 0.10
Orange
1.792
0.10 × 0.10 × 0.10
Orange
2.293
Yellow
Dc/g cm−3
2.069
8.480
l/mm−1
4.855
3.899
1.306
8.622
T/K
213(2)
2352
2.03/26.99
8648
4197
446
0.0790
0.0940
1.038
173(2)
912
2.11/30.04
4964
3556
196
0.0332
0.1098
0.926
173(2)
552
2.33/30.04
6094
3564
259
0.0744
0.1687
0.980
173(2)
640
2.49/30.04
3489
2511
145
0.0383
0.0865
1.070
173(2)
584
2.25/32.20
6234
3771
226
0.0449
0.1059
0.855
F(000)
H Limits/◦
No. independent data
No. data (I > 2r(I))
No. parameters
R1
wR2
GOF
Max./min. Dq/e A
−3
˚
1.198/−1.311
1.130/−1.650
2.060/−1.443
1.033/−1.069
1.854/−1.846
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Extraction of the residue with ether afforded an orange solu-
tion which was evaporated to dryness. Recrystallization from
THF–pentane afforded a mixture containing the brown cluster
3 P. Braunstein, E. Cura and G. E. Herberich, J. Chem. Soc., Dalton
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5
[Mo2Pt2(g -C5H4NMe2)2(CO)8] (19) (IR (KBr): m(CO): 2029w,
1962vs, 1874vs cm−1) and few crystals of the orange dimetallic
5
complex [Pt{Mo(g -C5H4NMe2)(CO)3}(NCPh)Cl] (Mo–Pt) (20).
Data for 17. Anal. Calc. for C34H30Mo2N4O6Pt: C, 41.77; H,
3.09; N, 5.73. Found: C, 42.54; H, 3.16; N, 6.02%. IR (KBr):
m(CO): 1886s, 1846s, 1802s cm−1.
9 G. E. Herberich, B. Schmidt and U. Englert, Organometallics, 1995, 14,
471.
Crystal structure determinations
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Organometallics, 1996, 15, 2707.
The data collections were performed on an ENRAF-Nonius
CAD4 diffractometer equipped with graphite monochromators
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˚
using Mo-Ka radiation (k = 0.71073 A, x–2h scan) for complex
11 and on a Nonius Kappa-CCD area detector diffractometer
13 R. J. Haines, R. S. Nyholm and M. H. B. Stiddard, J. Chem. Soc. A,
˚
(Mo-Ka, k = 0.71070 A, u-scan) for compounds 16, 17·2THF,
1968, 46.
14 B. N. Strunin, K. I. Grandberg, V. G. Andrianov, V. N. Setkina, E. G.
Perevalova, Y. T. Struchkov and D. N. Kursanov, Dokl. Akad. Nauk
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18 and 20. The relevant data are summarized in Table 2. The cell
parameters were determined from reflections taken from one set
of 10 frames (1.0◦ steps in u angle), each at 20 s exposure. The
structures were solved using direct methods (SHELXS97) and
refined against F2 using the SHELXL97 software. The absorption
was corrected empirically (with Sortav) for the area detector data,
whereas a numerical absorption correction was applied to the
intensity data of 11. All non-hydrogen atoms were refined with
anisotropic parameters. The hydrogen atoms were included in
their calculated positions and refined with a riding model in
SHELXL97.
CCDC reference numbers 297952–297956.
For crystallographic data in CIF or other electronic format see
DOI: 10.1039/b602106a
23 P. Braunstein, E. Keller and H. Vahrenkamp, J. Organomet. Chem.,
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24 M. D. Curtis, K. R. Han and W. M. Butler, Inorg. Chem., 1980, 19,
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25 R. J. Klingler, W. M. Butler and M. D. Curtis, J. Am. Chem. Soc., 1978,
100, 5034.
Acknowledgements
26 F. A. Cotton, L. Kruczynski and B. A. Frenz, J. Organomet. Chem.,
1978, 160, 93.
The work in Strasbourg was supported by the Ministry of
Research (PhD grants to N. A. and P. C.), the CNRS and the
Franco-German Research Training Group (GRK 532 of the
DFG). The work in Aachen was generously supported by the
Deutsche Forschungsgemeinschaft and the Fonds der Chemischen
Industrie. One of us (T. S. B. B.) thanks North-Eastern Hill
University, Shillong (India), for the grant of study leave. We are
grateful to A. DeCian (Strasbourg) for the collection of the X-ray
data and Dr R. Pattacini for help.
27 (a) C. P. Casey, R. M. Bullock, W. C. Fultz and A. L. Rheingold,
Organometallics, 1982, 1, 1591; (b) C. P. Casey, R. M. Bullock and F.
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28 F. Angelucci, A. Ricci, C. Lo Sterzo, D. Masi, C. Bianchini and G.
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29 T. E. Bitterwolf, S. Gallagher, J. T. Bays, B. Scallorn, A. L. Rheingold,
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30 D. E. Crotty, E. R. Corey, T. J. Anderson, M. D. Glick and J. P. Oliver,
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2958 | Dalton Trans., 2006, 2950–2958
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The Royal Society of Chemistry 2006
©