Manganese-gold and -silver mixed-metal clusters derived from the unsaturated binuclear complex [Mn2(CO)6 (μ-Ph2PCH2PPh2)]2-(Mn=Mn) and related anions

Article abstract of DOI:10.1021/om0304614

Reaction of the unsaturated dihydride [Mn₂(μ-H)₂(CO)₆(μ-dppm)] with Li[BHEt₃] proceeds stepwise, giving first the anionic hydride [Mn₂(μ-H)(CO)₆(μ-dppm)]^- and then the dianion [Mn₂(CO)₆(μ-dppm)]^2-, both having a formally double metal-metal bond. In contrast, reaction with Na[BH₄] gives cleanly the fluxional anionic trihydride [Mn₂(μ-H)H₂(CO)₆(μ-dppm)]^-, which is electron precise. A related electron-precise dianion, [Mn₂(CO)₈(μ-dppm)]^2-, is readily prepared by reducing [Mn₂(CO)₈(μ-dppm)] with Na amalgam and is protonated by [NH₄]PF₆ to give the corresponding dihydride [Mn₂H₂(CO)₈(μ-dppm)]. The unsaturated anions react cleanly with silver or gold complexes of the type [MCl(PR₃)] (M = Ag, R = Cy; M = Au, R = Ph, p-tol) to give the corresponding trinuclear hydride clusters [Mn₂M(μ-H)(CO)₆(μ-dppm)(PR₃)] or the tetranuclear clusters [Mn₂M₂(CO)₆(μ-dppm) (PR₃)₂] (X-ray study for M = Au, R = p-tol). The trinuclear manganese-gold cluster adds CO easily to give the electron-precise [Mn₂Au(μ-H)(CO)₇(μ-dppm){P(p-tol)₃}], but the tetranuclear clusters react with simple donors in a more complex way. For example, reaction with (EtO)₂POP(OEt)₂ (tedip) gives a mixture of the corresponding tetranuclear derivatives [Mn₂Au₂(CO)₅(μ-dppm)(PR₃)(μ-te dip)], arising from substitution of peripheral CO and PR₃ ligands, and the trinuclear alkoxyphosphido clusters [Mn₂Au{μ-P(OEt)₂}(CO)₆(μ-dppm) (PR₃)], derived from the cleavage of a P-O bond in the backbone of the diphosphite ligand. The acid-base behavior of the tetranuclear digold clusters has been further explored through the reaction with HBF₄·OEt₂, which gives the cationic hydride cluster [Mn₂Au₂(μ₃-H)(CO)₆(μ-dppm){P(p - tol)₃}₂]BF₄, and the reaction with SnCl₂, which gives the raft-type pentanuclear manganese-gold-tin cluster [Mn₂Au₂SnCl₂(CO)₆(μ-dppm) {P(p-tol)₃}₂], characterized through an X-ray study.

Full text of DOI:10.1021/om0304614

4500
Organometallics 2003, 22, 4500-4510
Ma n ga n ese-Gold a n d -Silver Mixed -Meta l Clu ster s
Der ived fr om th e Un sa tu r a ted Bin u clea r Com p lex
[Mn 2(CO)6(µ-P h 2P CH2P P h 2)]2-(Mn dMn ) a n d Rela ted
An ion s
Xiang-Yang Liu, V´ıctor Riera, and Miguel A. Ruiz*
Departamento de Qu´ımica Orga´nica e Inorga´nica, I.U.Q.O.E.M., Universidad de Oviedo,
E-33071 Oviedo, Spain
Maurizio Lanfranchi and Antonio Tiripicchio
Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica,
Universita` di Parma, Parco Area delle Science 17/ A, I-43100 Parma, Italy
Received J une 16, 2003
Reaction of the unsaturated dihydride [Mn2(µ-H)2(CO)6(µ-dppm)] with Li[BHEt3] proceeds
stepwise, giving first the anionic hydride [Mn2(µ-H)(CO)6(µ-dppm)]- and then the dianion
[Mn2(CO)6(µ-dppm)]2-, both having a formally double metal-metal bond. In contrast, reaction
with Na[BH4] gives cleanly the fluxional anionic trihydride [Mn2(µ-H)H2(CO)6(µ-dppm)]-,
which is electron precise. A related electron-precise dianion, [Mn2(CO)8(µ-dppm)]2-, is readily
prepared by reducing [Mn2(CO)8(µ-dppm)] with Na amalgam and is protonated by [NH4]PF6
to give the corresponding dihydride [Mn2H2(CO)8(µ-dppm)]. The unsaturated anions react
cleanly with silver or gold complexes of the type [MCl(PR3)] (M ) Ag, R ) Cy; M ) Au, R )
Ph, p-tol) to give the corresponding trinuclear hydride clusters [Mn2M(µ-H)(CO)6(µ-dppm)-
(PR3)] or the tetranuclear clusters [Mn2M2(CO)6(µ-dppm)(PR3)2] (X-ray study for M ) Au, R
) p-tol). The trinuclear manganese-gold cluster adds CO easily to give the electron-precise
[Mn2Au(µ-H)(CO)7(µ-dppm){P(p-tol)3}], but the tetranuclear clusters react with simple donors
in a more complex way. For example, reaction with (EtO)2POP(OEt)2 (tedip) gives a mixture
of the corresponding tetranuclear derivatives [Mn2Au2(CO)5(µ-dppm)(PR3)(µ-tedip)], arising
from substitution of peripheral CO and PR3 ligands, and the trinuclear alkoxyphosphido
clusters [Mn2Au{µ-P(OEt)2}(CO)6(µ-dppm)(PR3)], derived from the cleavage of a P-O bond
in the backbone of the diphosphite ligand. The acid-base behavior of the tetranuclear digold
clusters has been further explored through the reaction with HBF4‚OEt2, which gives the
cationic hydride cluster [Mn2Au2(µ3-H)(CO)6(µ-dppm){P(p-tol)3}2]BF4, and the reaction with
SnCl2, which gives the raft-type pentanuclear manganese-gold-tin cluster [Mn2Au2SnCl2-
(CO)6(µ-dppm){P(p-tol)3}2], characterized through an X-ray study.
In tr od u ction
and other related anions (Chart 1). Both 1 and 2 are
32-electron complexes; therefore, a double Mn-Mn bond
can be formulated for these anions. The combination of
multiple metal-metal bonds and negative charges is
rare among the binuclear transition-metal carbonyl
anions. In fact, there are only a few examples of those
anions, such as the paramagnetic [Fe2(µ-PtBu2)2(CO)5]-,3
the dihydrides [M2(µ-H)2(CO)8]2- (M ) Cr, Mo, W),4 and
the phosphide complexes [Fe2(µ-PPh2)(CO)6]- 5 and
[Mo2Cp2(µ-PR2)(µ-CO)2]- (R ) Cy, Ph, OEt; Cp ) C5H5).6
Therefore, exploring the chemistry of these unsaturated
anions was a matter of added interest. In this paper we
report the reactions of anions 1 and 2 toward gold and
Some time ago we reported the reduction reaction
of the dihydride [Mn2(µ-H)2(CO)6(µ-dppm)] (dppm )
Ph2PCH2PPh2) to give alkali-metal salts of [Mn2(CO)6-
(µ-dppm)]2- (1), an anionic complex displaying quite a
nucleophilic behavior despite the formal unsaturation
of the molecule.1 Subsequent work established that the
dppm bridge acts as a very efficient and robust ligand
in this anion, preserving the dimetal substrate from
disruption even under oxidation conditions.2 Because of
this, we decided to study in more detail the reactions of
[Mn2(µ-H)2(CO)6(µ-dppm)] with different reducing agents
in order to get anionic derivatives closely related to 1.
As will be shown, we have thus been able to prepare
the unsaturated hydride [Mn2(µ-H)(CO)6(µ-dppm)]- (2)
(3) Van der Linden, J . G. M.; Heck, J .; Walter, B.; Bottcher, H.-C.
Inorg. Chim. Acta 1995, 217, 29.
(4) Lin, J . T.; Hagen, G. P.; Ellis, J . E. J . Am. Chem. Soc. 1983,
105, 2296 and references therein.
(5) Seyferth, D.; Brewer, K. S.; Wood, T. G.; Cowie, M.; Hilts, R. W.
Organometallics 1992, 11, 2570.
(6) Garc´ıa, M. E.; Melo´n, S.; Ramos, A.; Riera, V.; Ruiz, M. A.;
Belletti, D.; Graiff, C.; Tiripicchio, A. Organometallics 2003, 22, 1983.
* To whom correspondence should be addressed. E-mail: mara@
sauron.quimica.uniovi.es.
(1) Liu, X. Y.; Riera, V.; Ruiz, M. A. Organometallics 1994, 13, 2925.
(2) Liu, X. Y.; Riera, V.; Ruiz, M. A.; Bois, C. Organometallics 2001,
20, 3007.
10.1021/om0304614 CCC: $25.00 © 2003 American Chemical Society
Publication on Web 09/25/2003

Manganese-Gold and -Silver Mixed-Metal Clusters
Organometallics, Vol. 22, No. 22, 2003 4501
Ch a r t 1
cies as expected (average ν(CO) values are 1833, 1894,
and 1975 cm-1 for 1, 2 and the parent dihydride,
respectively). Moreover, anion 2 exhibits a triplet 1H
NMR resonance at - 11.2 ppm, which is indicative of
the presence of a bridging hydride symmetrically placed
cis with respect to the diphosphine bridge (J PH ) 28 Hz,
to be compared to J PH ) 21 Hz for the starting
dihydride).13 All attempts to isolate this unstable anion
resulted in its rapid decomposition.
As expected, anion 2 reacts with another 1 equiv of
Li[BHEt3] to yield 1, and it also gives the starting
dihydride upon reaction with [NH4]PF6. Surprisingly,
protonation of 1 cannot be controlled so as to give 2.
Thus, when 1 is reacted with 1 equiv of [NH4]PF6, only
the neutral dihydride and unreacted 1 are present in
the reaction mixture.
Reaction of [Mn2(µ-H)2(CO)6(µ-dppm)] with Na[BH4]
also takes place easily in tetrahydrofuran solution but
leads to a completely different result, as it gives cleanly
the yellow-orange trihydride anion [Mn2(µ-H)H2(CO)6-
(µ-dppm)]- (3, Na+ salt, Chart 1). The IR spectrum for
this electron-precise anion exhibits ν(CO) bands in a
region similar to those of 2, and its 31P NMR spectrum
is also indicative of the chemical equivalence of both
metal centers. However, the 1H NMR spectrum of 3
exhibits a single and broad resonance at -13.98 ppm,
with a relative intensity corresponding to 3 H atoms.
All the above data are analogous to those found for
Na[Mn2(µ-H)H2(CO)6(µ-tedip)] (tedip ) (EtO)2POP-
(OEt)2), a fluxional trihydride anion prepared analo-
gously from [Mn2(µ-H)2(CO)6(µ-tedip)] and Na[BH4].10
We thus assume that anion 3 also experiences dynamic
exchange between bridging and terminal hydride posi-
tions. Although we have not explored the reactivity of
this anion in detail, initial experiments suggest that it
behaves as the aforementioned tedip-bridged trihydride.
For example, reaction of 3 with [CuCl(PPh3)]4 gives a
trihydride Mn2Cu cluster similar to [Mn2Cu(µ-H)3(CO)6-
(µ-tedip)(PPh3)].10
P r ep a r a tion a n d Str u ctu r a l Ch a r a cter iza tion of
[Mn 2(CO)8(µ-d p p m )]2- (4). Although formally unsat-
urated, anions 1 and 2 do not react with CO to give an
electron-precise anion. With the aim of finding a syn-
thetic connection between electron-precise precursors
and unsaturated anions, we attempted the synthesis of
[Mn2(CO)8(µ-dppm)]2- using conventional synthetic
routes. This was easily accomplished by reacting the
singly bonded [Mn2(CO)8(µ-dppm)] with Na amalgam in
tetrahydrofuran, thus paralleling the metal-metal bond
cleavage of unbridged [Mn2(CO)10] and [Mn2(CO)8L2]
complexes (L ) phosphine or phosphite ligand).14,15
The IR spectrum of anion 4 (Na+ salt) in tetrahydro-
furan solution exhibits five partially split CO stretching
bands, while its 31P NMR spectrum exhibits a single
NMR resonance. The high number of IR bands (a total
of eight) for 4 is indicative of substantial Na+-anion
silver phosphine complexes of the type [MCl(PR3)].
Although this is a classical synthetic route to hetero-
metallic group 11-transition-metal compounds,7 the
electron deficiency present in anions 1 and 2 makes
these compounds rational synthetic precursors for un-
saturated clusters having Mn-Au or Mn-Ag bonds,
only a limited number of which are known,8-12 thus
allowing the study of their chemical behavior. We have
done this by investigating the reactions of the new
unsaturated clusters with some simple acids and bases.
Resu lts a n d Discu ssion
An ion ic Hyd r id es Der ived fr om [Mn 2(µ-H)2(CO)6-
(µ-d p p m )]. As we have reported previously, reactions
of the title dihydride with Na amalgam, potassium, or
an excess of Li[BHEt3] gives the corresponding alkali-
metal salt of anion 1.2 Under normal conditions, no
intermediate species can be detected in these reactions.
However, when using just 1 equiv of the lithium
reagent, a dark brown solution is obtained, shown by
IR and NMR to contain the unsaturated anion [Mn2(µ-
H)(CO)6(µ-dppm)]- (2, Li+ salt) as the major species. We
should stress that no other reagent was found to allow
for a convenient synthesis of this intermediate anion.
Anion 2 is characterized by a single 31P NMR reso-
nance at 72.0 ppm (close to that for 1) and CO stretching
bands (Table 1) with a pattern similar to those of 1 or
the parent dihydride, but having intermediate frequen-
(7) Reviews: (a) Robert, D. A.; Geoffroy, G. L. In Comprehensive
Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E. W.,
Eds.; Pergamon: Oxford, U.K., 1982; Vol. 6, Chapter 40. (b) Salter, I.
D. Adv. Organomet. Chem. 1989, 29, 249. (c) Mingos, D. M. P.; Watson,
M. J . Adv. Inorg. Chem. 1992, 39, 327. (d) Salter, I. D. In Comprehen-
sive Organometallic Chemistry, 2nd ed.; Abel, E. W., Stone, F. G. A.,
Wilkinson, G., Eds.; Pergamon: Oxford, U.K., 1995; Vol. 10, Chapter
5.
(8) Liu, X. Y.; Riera, V.; Ruiz, M. A.; Tiripicchio, A.; Tiripicchio-
Camellini, M. Organometallics 1996, 15, 974.
(9) Carren˜o, R.; Riera, V.; Ruiz, M. A.; Tiripicchio, A.; Tiripicchio-
Camellini, M. Organometallics 1994, 13, 993.
(10) (a) Riera, V.; Ruiz, M. A.; Tiripicchio, A.; Tiripicchio-Camellini,
M. Organometallics 1993, 12, 2962. (b) Riera, V.; Ruiz, M. A.;
Tiripicchio, A.; Tiripicchio-Camellini, M. J . Chem. Soc., Chem. Com-
mun. 1985, 1505.
(13) (a) Garc´ıa-Alonso, F. J .; Riera, V.; Ruiz, M. A.; Tiripicchio, A.;
Tiripicchio-Camellini, M. Organometallics 1992, 11, 370. (b) Garc´ıa-
Alonso, F. J .; Garc´ıa-Sanz, M.; Riera, V.; Ruiz, M. A.; Tiripicchio, A.;
Tiripicchio-Camellini, M. Angew. Chem., Int. Ed. Engl. 1988, 27, 1167.
(14) (a) King, R. B. Adv. Organomet. Chem. 1964, 2, 157. (b) Treichel,
P. M. In Comprehensive Organometallic Chemistry; Wilkinson, G.,
Stone, F. G. A., Abel, E. W., Eds.; Pergamon: Oxford, U.K., 1982; Vol.
4, Chapter 29.
(11) Carren˜o, R.; Riera, V.; Ruiz, M. A.; Bois, C.; J eannin, Y.
Organometallics 1992, 11, 2923.
(12) Haupt, H. J .; Heinekamp, C.; Flo¨rke, U.; J uptner, U. Z. Anorg.
Allg. Chem. 1992, 608, 100.
(15) Darensbourg, M. Y.; Darensbourg, D. J .; Burns, D.; Drew, D.
A. J . Am. Chem. Soc. 1976, 98, 3127.

4502 Organometallics, Vol. 22, No. 22, 2003
Ta ble 1. IR a n d 31P {1H} NMR Da ta for New Com p ou n d s
Liu et al.
compd
νst(CO)a/cm-1
δ(P)b/ppm
Na2[Mn2(CO)6(µ-dppm)] (1)
1888 (s), 1841 (vs), 1817 (s), 1787 (s)c
1967 (s), 1901 (vs), 1866 (s), 1840 (m)c
67.0d
72.0e
Li[Mn2(µ-H)(CO)6(µ-dppm)] (2)
Na[Mn2(µ-H)H2(CO)6(µ-dppm)] (3)
Na2[Mn2(CO)8(µ-dppm)] (4)
1983 (s), 1919 (vs), 1900 (m, sh), 1866 (m), 1843 (w)c 63.5
1940 (s, sh), 1935 (s), 1850 (s), 1825 (s, sh),e
1816 (vs), 1803 (s, sh), 1755 (m, sh)c
2060 (m), 1992 (m), 1988 (m), 1966 (vs),
1947 (m, sh), 1928 (w)f
88.9d
[Mn2H2(CO)8(µ-dppm)] (5)
59.6g
[Mn2Ag(µ-H)(CO)6(µ-dppm)(PCy3)] (6)
1994 (vs), 1951 (vs), 1912 (m), 1881 (s)
2002 (vs), 1966 (vs), 1922 (m), 1893 (s)
2021 (s), 1950 (vs), 1931(s), 1909 (m, sh), 1869 (m)
1954 (m), 1910 (vs), 1876 (w), 1850 (s)
1972 (s), 1935(vs), 1896 (w), 1870 (s)
1972 (s), 1936 (vs), 1899 (w), 1871 (s)
1981 (m), 1928 (vs), 1912 (m, sh), 1893 (m), 1851 (w) Table 3
1980 (m), 1928 (vs), 1910 (m, sh), 1893 (m), 1852 (w) Table 3
1994 (s), 1962 (vs), 1919 (m), 1902 (sh, s), 1894 (s)
66.5 (d, br), 30.8 (2 × dt)h
70.0 (t),i 65.2 (s, br)g
64.0 (s, br), 46.4 (s)
73.1 (tt), 29.2 (2 × dt)j
66.9 (br), 64.9 (t)k
[Mn2Au(µ-H)(CO)6(µ-dppm){P(p-tol)3}] (7)
[Mn2Au(µ-H)(CO)7(µ-dppm){P(p-tol)3}] (8)
[Mn2Ag2(CO)6(µ-dppm)(PCy3)2] (9)
[Mn2Au2(CO)6(µ-dppm)(PPh3)2] (10a )
[Mn2Au2(CO)6(µ-dppm){P(p-tol)3}2] (10b)
[Mn2Au2(CO)5(µ-dppm)(PPh3)(µ-tedip)] (11a )
[Mn2Au2(CO)5(µ-dppm){P(p-tol)3}(µ-tedip)] (11b)
[Mn2Au{µ-P(OEt)2}(CO)6(µ-dppm)(PPh3)] (12a )
69.2 (br), 65.7 (t)k
Table 3
Table 3
[Mn2Au{µ-P(OEt)2}(CO)6(µ-dppm) {P(p-tol)3}2] (12b) 1993 (s), 1962 (vs), 1919 (m), 1902 (sh, s), 1893 (s)
[Mn2Au2(µ-H)(CO)6(µ-dppm){P(p-tol)3}2]BF4 (13)
[Mn2Au2SnCl2(CO)6(µ-dppm){P(p-tol)3}2] (14)
2015 (s), 1986 (vs), 1949 (m), 1924 (s)
1991 (vs), 1943 (s), 1927 (s), 1890 (m), 1860 (m)
63.7 (br), 62.7 (s, br)
51.5 (false t), 49.9 (s, br)l
a
b
In dichloromethane solution, unless otherwise stated. Measured at 121.5 MHz, in CD2Cl2 solution at room temperature, unless
otherwise stated; coupling constants (J ) in Hz. c In tetrahydrofuran (THF) solution. In THF/C6D6 (9/1) solution. e In THF/D2O solution.
d
f In petroleum ether solution. In C6D6 solution. Recorded at 233 K, J (Ag-PPh) ) 12, J (109Ag-PCy) ) 358, J (107Ag-PCy) ) 310, J (PP)
g
h
) 7. Au-P; J (PP) ) 14. Recorded at 218 K; J (Ag-PPh) ) 16, J (109Ag-PCy) ) 358, J (107Ag-PCy) ) 311, J (PP) ) 6. J (PP) ) 14.
i
j
k
l
|J (PP)+J (PP′)| ) 16; when recorded at 188 K δ 52.4 (s, br, J (PSn) ) 243), 46.9 (s, br, J (PSn) ) 175).
Ch a r t 2
Ch a r t 3
interactions, this being common in mononuclear car-
bonylates.16 In fact, the IR spectrum of 4 is very similar
to that reported for Na[Mn(CO)4(PMe2Ph)] in tetrahy-
drofuran (1940.8 (m)*, 1934.7 (w), 1847.6 (m), 1817.1
(s), 1802.5 (m), 1767 (m)* cm-1, with the asterisks
labeling the bands attributed to the Na+-anion pairs].15
In the latter anion, the phosphine ligand occupies an
axial position (C3v symmetry). However, the high-
frequency bands for 4 are of high intensity, which is
indicative of a lower symmetry. Therefore, we propose
that the P atoms in 4 occupy equatorial positions (local
C2v symmetry), which perhaps could be explained on
steric grounds.
As expected, anion 4 is easily protonated to give the
corresponding dihydride [Mn2H2(CO)8(µ-dppm)] (5) in
high yield. The IR spectrum for 5 in the CO stretching
region is very similar to those for the halide complexes
[Mn2X2(CO)8(µ-tedip)],17 and thus a similar structure is
assumed for 5, with two cis-Mn(CO)4H fragments joined
by the dppm bridge (Chart 2). In agreement with this
proposal, the 1H NMR spectrum of 5 displays a rela-
tively poorly shielded resonance (δ -7.26 ppm), indica-
tive of terminal coordination, and an H-P coupling
around 40 Hz (for comparison, the hydride ligand in fac-
[MnH(CO)3(Ph2PCH2CH2PPh2)] gives rise to a triplet
resonance at δ -7.8 ppm with J PH ) 45 Hz).18
the latter currently requiring the completion of some
tedious synthetic steps.13 Unfortunately, those expecta-
tions have not been fulfilled. Although we have found
that irradiation with UV-visible light of toluene or
tetrahydrofuran solutions of 5 at -40 °C gives indeed
some of the targeted dihydride, this reaction has a poor
selectivity and also gives considerable amounts of the
known complexes [Mn2(µ-η1:η2-CO)(CO)4(µ-dppm)2]19
and [Mn2(µ-H)2(CO)4(µ-dppm)2];20 therefore, the reaction
has no synthetic utility. Noticeably, the reverse reaction
does not occur either. In fact, carbonylation of the
unsaturated [Mn2(µ-H)2(CO)6(µ-dppm)] gives the metal-
metal-bonded [Mn2(CO)8(µ-dppm)] rather than dihy-
dride 5.
Silver a n d Gold Der iva tives of Hyd r id e An ion
2. The Li+ salt of anion 2, prepared in situ as described
above, reacts rapidly with equivalent amounts of the
halide complexes [AgCl(PCy3)]4 and [AuCl{P(p-tol)3}] to
give the corresponding mixed-metal hydride clusters
[Mn2M(µ-H)(CO)6(µ-dppm)(PR3)] (6, M ) Ag, R ) Cy;
7, M ) Au, R ) p-tol) (Chart 3). As concluded from the
analysis of the corresponding spectroscopic data (Table
1 and Experimental Section), these blue-violet com-
pounds are completely analogous to the Au-Mn clusters
[Mn2Au(µ-H)(CO)6(µ-L2)(PPh3)], prepared from the cor-
responding dihydride [Mn2(µ-H)2(CO)6(µ-L2)] and [AuMe-
(PPh3)] (L2 ) tedip,10 dppm11). We recall here that the
Compound 5 might be considered as a convenient
precursor for the unsaturated [Mn2(µ-H)2(CO)6(µ-dppm)],
(16) Darensbourg, M. Y. Prog. Inorg. Chem. 1985, 33, 221.
(17) Riera, V.; Ruiz, M. A. J . Chem. Soc., Dalton Trans. 1986, 2617.
(18) Booth, B. L.; Haszeldine, R. N. J . Chem. Soc. A 1966, 157.
(19) Colton, R.; Commons, C. J . Aust. J . Chem. 1975, 28, 1673.
(20) Aspinall, H. C.; Deeming, A. J . J . Chem. Soc., Chem. Commun.
1983, 838.

Manganese-Gold and -Silver Mixed-Metal Clusters
Organometallics, Vol. 22, No. 22, 2003 4503
Ch a r t 4
tedip-bridged compound exhibits a very short value of
2.739(3) Å for the Mn-Mn distance, in agreement with
the electronic unsaturation of all these clusters, which
retain a formally double Mn-Mn bond. From a syn-
thetic point of view, anion 2 thus represents an alterna-
tive preparative route to Mn-Au compounds but is still
a unique entry to unsaturated Mn-Ag clusters. As we
will see below, the same applies to anion 1.
The presence of the hydride ligand in complexes 6 and
7 is clearly denoted by the appearance of a quite
shielded resonance at ca. -21 ppm in their 1H NMR
spectra. In addition, the silver nuclei in 6 exhibit a small
two-bond coupling to the bridging diphosphine (12 Hz)
and large one-bond coupling to the PCy3 phosphorus
atom, as expected. The absence of two-bond H-Ag
coupling in 6 is somewhat unexpected, as values of 12-
24 Hz have been measured for the electron-precise
clusters [Mn4Ag2(µ-H)6(CO)12(µ-tedip)2]9 and [Mn2Ag(µ-
H)3(CO)6(µ-tedip)(PPh3)].10 This difference might be
related to the unsaturated nature of 6, expected to
display a Mn-Mn separation ca. 0.5 Å shorter than the
saturated clusters, whereby substantial changes in the
H-Mn-Ag angles are to be expected. It is well-known
that two-bond coupling is quite sensitive to the bond
angle involved and that the coupling constant might
even change from negative to positive values upon an
increase in the bond angle.21
equiv of [AgCl(PCy3)]4 or [AuCl(PR3)] to give the corre-
sponding tetranuclear clusters [Mn2M2(CO)6(µ-dppm)-
(PR3)2] (9, M ) Ag, R ) Cy; 10a , M ) Au, R ) Ph; 10b,
M ) Au, R ) p-tol) in good yields (Chart 4). No
intermediate trinuclear clusters were detected when
using just 1 equiv of the silver or gold complexes, thus
paralleling our inability to stop the protonation reaction
so as to yield anion 2 from 1.
The structure of 10b has been determined through
an X-ray study and is depicted in Figure 1, while Table
2 collects some relevant bond lengths and angles. The
cluster can be viewed as two Mn(CO)3 moieties bridged
by the diphosphine and by two Au-P(p-tol)3 fragments;
thus, a distorted-octahedral environment around each
Mn atom can be envisaged. The Mn2Au2 core is in a
flattened-butterfly arrangement, with the two AuMn2
wings forming a dihedral angle of 17.51(9)°. The octa-
hedral geometry for the Mn atoms and the digonal
geometry for the Au atoms can be better explained by
considering three-center-two-electron (3c-2e) bonds
involving orbitals pointing toward the centers of the two
Mn2Au triangles. The short Mn-Mn separation of
2.865(4) Å is in agreement with the two 3c-2e bonds
and is also consistent with the formal double Mn-Mn
bond expected for this molecule on the basis of the EAN
rule. Indeed, this value is significantly shorter than
those found in the related electron-precise cluster
[Mn2Au(µ-Br)(CO)6(µ-tedip)(PR3)] (3.090(2) Å],24 while
it is identical within experimental error to that found
in [Mn2Au2(µ3-H)(CO)6(µ-dppm)(PR3)]PF6 (2.864(5) Å),11
a cationic cluster isoelectronic with clusters 9 and 10
(see below). However, these figures are significantly
higher than those measured in the isolobal-related
compounds [Mn2(µ-H)2(CO)6(µ-dppm)] (2.699(2) Å)13b
and [Mn2Au(µ-H)(CO)6(µ-tedip)(PR3)] (2.739(3) Å).10 We
interpret this as a steric effect derived from the close
proximity of the relatively bulky dppm and P(p-tol)3
ligands, and this effect also would give a rationale for
the significant bending of one of the Au-P(p-tol)3 groups
away from the dppm bridge. As can be appreciated
through the projection of the molecule along the Mn-
Mn bond, the Au(1)-P(3) atoms lie in a plane almost
perpendicular to the average Mn(1)Mn(2)P(1)P(2) plane,
as expected. In contrast, the Au(2)-P(4) atoms are
significantly displaced away from that plane. This can
be attributed to the close proximity between one of the
phenyl groups bonded to P(1) and a p-tolyl ring on P(4),
these having C-H‚‚‚C separations in the range 3.1-
3.2 Å, which are close to the sum of the van der Waals
radii for H and C atoms (ca. 3.0 Å). This means that
the Au(2)P(p-tol)3 bridging group cannot get any closer
Compounds 6 and 7 are electron deficient and there-
fore expected to add simple ligands easily. Indeed, the
Mn-Au cluster adds carbon monoxide easily, to give the
electron-precise [Mn2Au(µ-H)(CO)7(µ-dppm){P(p-tol)3}]
(8). Spectroscopic data for this complex (Table 1 and
Experimental Section) indicate that the uptake of a CO
ligand causes a dramatic structural rearrangement in
the molecule, whereby the hydride ligand moves from
a Mn2(µ-H) position into a Mn(µ-H)Au one, as deduced
from its considerably low shielding (δ -5.43 ppm) and
large coupling to the P atom on gold (J HP ) 92 Hz), well
inside the range found for H atoms bridging M-AuPR3
bonds (80-110 Hz).22,23 The presence of a single reso-
nance in the 31P NMR spectrum and the grouping of
the carbonyl 13C resonances into a 1:2:4 pattern might
suggest the presence of a plane of symmetry relating
both manganese moieties in 8. This would imply the
presence of a bridging carbonyl. However, the latter is
inconsistent with the absence of the characteristic
spectroscopic features for this coordination mode of CO
(high 13C chemical shift and low CO stretching fre-
quency). The situation is thus analogous to that en-
countered for the related tedip-bridged cluster [Mn2Au-
(µ-H)(CO)7(µ-tedip)(PPh3)], which was found to have an
asymmetric fluxional structure.10 We then propose for
8 a similar structure (Chart 3), although we have found
no direct experimental evidence for this fluxional be-
havior. In fact, the P atoms of the diphosphine ligand
in 8 remained equivalent in the 31P spectrum down to
188 K.
Silver a n d Gold Der iva tives of An ion 1. The Na+
salt of anion 1 reacts rapidly in tetrahydrofuran with 2
(21) J ameson, C. J . In Phosphorus-31 NMR Spectroscopy in Stereo-
chemical Analysis; Verkade, J . G., Quin, L. D., Eds.; VCH: Deerfield
Beach, FL, 1987; Chapter 6.
(22) Green, M.; Orpen, A. G.; Salter, I. D.; Stone, F. G. A. J . Chem.
Soc., Dalton Trans. 1984, 2497.
(23) Albinati, A.; Auklin, C.; J anser, P.; Lehner, H.; Matt, D.;
Pregosin, P. S.; Venanzi, L. M. Inorg. Chem. 1989, 28, 1105.
(24) Riera, V.; Ruiz, M. A.; Tiripicchio, A.; Tiripicchio-Camellini, M.
J . Chem. Soc., Dalton Trans. 1987, 1551.

4504 Organometallics, Vol. 22, No. 22, 2003
Liu et al.
F igu r e 1. Molecular structure of compound 10b (left) and its projection along the Mn-Mn bond (right; CO ligands omitted
for clarity). Ellipsoids represent 30% probability.
electronegative AuPPh3 fragment.10 Moreover, spectro-
scopic data are similar for 9 and 10a ,b, therefore
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Com p ou n d s 10b a n d 14
indicating that all these tetranuclear clusters have the
same structure. For the silver cluster 9 the average CO
stretching frequency is some 22 cm-1 lower than that
value for the gold clusters 10, almost doubling the
difference calculated between 6 and 7, thus revealing
the presence of additive effects. Other spectroscopic
features for the Ag-PCy3 fragments are very similar
to those found in 6, thus indicating a very similar
binding of the µ-AgPCy3 groups.
Compound 10b
Mn(1)-Mn(2)
Mn(1)-Au(1)
Mn(1)-Au(2)
P(1)-Mn(1)
P(3)-Au(1)
2.865(4)
Mn(2)-Au(1)
Mn(2)-Au(2)
P(2)-Mn(2)
P(4)-Au(2)
2.672(3)
2.669(3)
2.320(5)
2.342(4)
2.696(3)
2.690(3)
2.308(5)
2.339(4)
Au(2)-Mn(1)-Au(1) 112.60(10) Au(2)-Mn(2)-Au(1) 114.09(10)
Mn(2)-Au(1)-Mn(1)
P(1)-Mn(1)-Au(2)
P(1)-Mn(1)-Au(1)
P(1)-Mn(1)-Mn(2)
64.51(8)
Mn(2)-Au(2)-Mn(1)
64.64(8)
106.03(14)
89.10(13)
90.34(15)
99.63(14) P(2)-Mn(2)-Au(2)
96.72(14) P(2)-Mn(2)-Au(1)
91.51(15) P(2)-Mn(2)-Mn(1)
The presence of the basic PCy3 phosphine gives
substantial stability to the disilver cluster 9. In fact, a
similar Mn2Ag2 cluster can be prepared by reacting 1
and [AgCl{P(p-tol)3}]4, but this product experiences
progressive decomposition during all attempts at puri-
fication (crystallization, chromatography, etc.). We trust
that this is a genuine electronic effect, so that AgPR3
fragments would become overly strong oxidants when
they have electron-withdrawing R groups. In agree-
ment with this, all attempted reactions between 1 and
[CuCl(PR3)]4 complexes lead to electron transfer rather
than formation of heterometallic Mn2Cu2 clusters.
Compound 14
Mn(1)-Mn(2)
Au(1)-Mn(1)
Sn-Mn(1)
Au(1)-Sn
Au(1)-P(3)
Au(1)-C(1)
Sn-Cl(1)
3.171(9)
2.651(7)
2.602(7)
2.813(4)
2.303(11)
2.63(6)
Au(2)-Mn(2)
Sn-Mn(2)
Au(2)-Sn
Au(2)-P(4)
Au(2)-C(4)
Sn-Cl(2)
2.654(6)
2.600(7)
2.815(4)
2.296(11)
2.53(4)
2.428(11)
2.335(13)
2.401(10)
2.345(14)
Mn(2)-P(2)
Mn(1)-P(1)
Sn-Mn(1)-Mn(2)
Sn-Mn(1)-Au(1)
52.43(17) Sn-Mn(2)-Mn(1)
64.75(16) Sn-Mn(2)-Au(2)
52.47(17)
64.79(16)
Au(1)-Mn(1)-Mn(2) 116.9(2)
Au(2)-Mn(2)-Mn(1) 117.2(2)
P(2)-Mn(2)-Mn(1)
P(1)-Mn(1)-Mn(2)
Mn(1)-Au(1)-Sn
Cl(1)-Sn-Cl(2)
Mn(1)-Sn-Au(1)
Au(1)-Sn-Au(2)
88.1(4)
56.77(15) Mn(2)-Au(2)-Sn
98.7(4) Mn(2)-Sn-Mn(1)
91.0(4)
56.68(14)
75.1(2)
The synthetic value of anion 1 can be grasped from
the fact that the tetranuclear clusters 9 and 10 are
among the first examples of unsaturated Mn2M2 clusters
to be reported. We have previously described a moder-
ate-yield synthesis for a closely related Mn2Au2 cluster,
prepared through the photochemical reaction between
[Mn2Au(µ-H)(CO)6(µ-tedip)(PR3)] and [AuMe(PPh3)].
However, this synthetic method does not work with the
dppm-bridged compounds nor can it be obviously used
in the preparation of silver derivatives.
58.47(15) Mn(2)-Sn-Au(2)
167.82(13)
58.53(15)
to the dppm bridge without experiencing severe repul-
sion with the phenyl rings. An indirect evidence for the
steric origin of the lengthening of the Mn-Mn vector
in 10b comes from comparison with the closely related
series of clusters of formula [Os3(µ-X)2(CO)10] (X ) H,
AuPPh3), where the double Os-Os bonds display values
almost independent of X, these being 2.681(1),25a
2.699(1),25b and 2.684(1) Å,25c for the Os3, Os3Au, and
Os3Au2 clusters, respectively.
Spectroscopic data for 10b in solution (Table 1 and
Experimental Section) are consistent with its solid-state
structure. Its IR spectrum exhibits four strong CO
stretching bands, in agreement with a C2v symmetry,
with frequencies some 30 cm-1 lower than those for 7,
as expected when a bridging H is replaced by the less
Acid -Ba se Ch em istr y of th e Un sa tu r a ted Clu s-
ter s 10. Compounds 10 are related to dihydrides
[Mn2(µ-H)2(CO)6(µ-L2)] through the isolobal analogy
H/AuPPh3.26 Thus, a similar chemical behavior between
all these species is to be expected. However, the lower
electronegativity of the gold fragment relative to hy-
drogen, clearly denoted by the values of the CO stretch-
ing frequencies already mentioned, expectedly should
make compounds 10 to be better donors and poorer
acceptors than the parent dihydrides. Besides, we have
recognized the presence of some steric pressure in the
(25) (a) Churchill, M. R.; Hollander, F. J .; Hutchinson, P. Inorg.
Chem. 1977, 16, 2697. (b) Burgess, K.; J ohnson, B. F. G.; Kaner, D.
A.; Lewis, J .; Raithby, P. R.; Azman, S. N.; Syed-Mustaffa, B. J . Chem.
Soc., Chem. Commun. 1983, 455. (c) J ohnson, B. F. G.; Kaner, D. A.;
Lewis, J .; Raithby, P. R. J . Organomet. Chem. 1981, 215, C33.
(26) Evans, D. G.; Mingos, D. M. P. J . Organomet. Chem. 1982, 232,
171.

Manganese-Gold and -Silver Mixed-Metal Clusters
Organometallics, Vol. 22, No. 22, 2003 4505
Ta ble 3. 31P {1H} NMR Da ta for Com p ou n d s 11 a n d 12a
δ/ppm
P(3)
J (PP)/Hz
compd
P(1)
P(2)
P(4)
P(5)
12
14
24
25
35
45
11a (isomer A)b
11b (isomer A)c
11a (isomer B)b
11b (isomer B)c
12a d
68.3 (dd)
70.3 (dd)
70.1 (dd)
71.8 (dd)
56.3 (dd)
56.4 (dd)
48.6 (d)
48.3 (d)
60.3 (ddd)
59.6 (ddd)
65.9 (t)
53.4 (s)
52.7 (s)
57.4 (d)
56.5 (d)
181.5 (m)
182.4 (dd)
184.4 (m)
185.7 (br, td)
420.6 (t)
186.3 (br, d)
187.6 (d)
179.8 (m)
145
150
152
152
50
51
58
58
11
11
65
65
60
60
15
14
33
33
52
53
20
22
181.9 (br, td)
12b
64.7 (t)
420.8 (t)
a
Measured at 162.0 MHz, in CD2Cl2 solution at room temperature, unless otherwise stated; coupling constants (J ) in Hz. Labeling is
given according to the figure below. A:B ) 1:2. c In C6D6 solution. Recorded at 243 K.
b
d
Ch a r t 5
structure of 10b, a fact that could also have a significant
effect on the reactivity of these clusters.
We have checked the general acid-base behavior of
these tetranuclear clusters by studying some reactions
of 10 with simple donors (CO, phosphines), with pure
acceptors (H+), and with some fragments related to the
methylene fragment, which then involve both donor and
acceptor interactions with the metal substrate.
In contrast with the behavior observed for the tri-
nuclear cluster 7, the digold clusters 10 do not react
with CO under ordinary conditions of temperature and
pressure. We view this as an effect of the increased
electron density at the dimanganese center when re-
placing H by AuPR3 moieties, thus reducing the over-
all acidity. As expected, reaction occurs when using
stronger donors as phosphines, although results are
strongly dependent on the added ligand. For example,
PMe3 reacts instantaneously with compounds 10 by
completely destroying the clusters, thus giving products
of the type [Mn2(CO)4(µ-dppm)(PMe3)2(PR3)2], which
were not fully characterized. In contrast, the less basic
and bidentate ligands dppm and tedip react rapidly with
10 without breakdown of the metal core.
NMR spectra also confirm that a dppm ligand bridges
equivalent manganese centers and that just a gold-
bonded phosphine remains in these complexes. Finally,
the IR spectrum of complexes 12 exhibits the five-band
pattern characteristic of hexacarbonyl [Mn2(µ-X)(µ-Y)-
(CO)6(µ-L2)] complexes having fac-Mn(CO)3 oscillators
(X, Y ) one- or three-electron-donor ligands). In fact,
CO stretching frequencies are quite similar to those for
7 (Table 1). All these data unambiguously define for
complexes 12 the structure depicted in Chart 5. This
structure is completely analogous to that determined
crystallographically for [Mn2Au(µ-Br)(CO)6(µ-tedip)-
(PPh3)].24
We have studied in detail the reactions of clusters 10
with tedip. These take place within a few minutes at 0
°C to give in both cases a black-blue intermediate which
could not be fully characterized. The latter intermedi-
ates rearrange at room temperature to give the corre-
sponding blue-violet pentacarbonyl clusters [Mn2Au2-
(CO)5(µ-dppm)(PR3)(µ-tedip)] (11a ,b) and the orange,
electron-precise clusters [Mn2Au{µ-P(OEt)2}(CO)6(µ-
dppm)(PR3)] (12a ,b). Clusters 11 and 12 were obtained
in all cases in a ca. 3:1 ratio. This product distribution
was found to be rather insensitive to experimental
conditions such as reaction time and solvent.
Structural characterization for the violet clusters 11
is less straightforward. Although we were not able to
grow good-quality crystals of those compounds, the
available spectroscopic data allow us to establish both
the composition and the main structural features of
these compounds (Tables 1 and 3 and Experimental
Section). In the first place, the IR spectra of compounds
11 differ from those recorded for the hexacarbonyl
compounds described above. The absence of one of the
two characteristic high-frequency CO bands suggests
the presence of a pentacarbonyl (CO)3MnMn(CO)2 oscil-
lator in the molecule. On the other hand, the 31P and
1H NMR spectra indicate that clusters 11 exist in
solution as a mixture of two isomers in each case,
labeled A and B (Chart 6 and Table 3). Each isomer
contains one tedip bridge, one dppm bridge, and just
one gold-bonded phosphine ligand. The ratio of isomers
does not change significantly with temperature but is
somewhat solvent-dependent. All the above data suggest
that isomers 11 are just the result of replacing a
Spectroscopic data for 12 (Tables 1 and 3 and Experi-
mental Section) allow for a complete characterization
of these clusters. The presence of an unexpected di-
ethoxyphosphide group is readily apparent from the 31P
NMR spectra, which exhibit in both cases a strongly
deshielded resonance at ca. 420 ppm, a value very close
to those measured for all clusters derived from the anion
1
[Mn2{µ-P(OEt)2}{µ-OP(OEt)2}(CO)6]2-.8 The 31P and H

4506 Organometallics, Vol. 22, No. 22, 2003
Liu et al.
Ch a r t 6
Ch a r t 7
phosphine and a carbonyl group in clusters 10 by a tedip
bridge. There are precedents of these substitution
reactions in heterometallic carbonyl clusters containing
group 11 element MPR3 fragments.7d
(OP(OEt)2) groups, followed by extrusion of a gold
phosphonate moiety and capture of some CO present
in the solution. A close precedent for this rare process
can be found in the electron-precise manganese-gold
clusters [Mn2Au2{µ-P(OEt)2}{µ-OP(OEt)2](CO)6(PR3)2],
which experience loss of the phosphonate group under
various conditions to give the unsaturated pentanuclear
clusters [Mn2Au3{µ-P(OEt)2}(CO)6(PR3)3].8
The assignment of 31P NMR resonances for clusters
11 (Table 3) is based on the assumption that the shift
for P(1) should be very similar to those in clusters 10
and should not change much from one isomer to other,
because of the similarity in the relevant chemical
environments. From this, assignment of P(2) follows
through its large PP coupling. This leads in turn to
identify the gold-bonded P(3) as a weakly (isomer B) or
not coupled (isomer A) resonance, as expected.
Isomers A and B strongly differ (by ca. 11 ppm) in
the chemical shift of the diphosphine P(2) resonance,
which we attribute to a change in the ligand trans to
that phosphorus atom. We then assign the lowest shift
to the isomer having P(2) trans to the better π-acceptor
ligand (CO). The inequivalent phosphorus atoms of the
tedip ligand in these isomers give rise to broad, ill-
resolved multiplets at ca. 180 ppm. Despite this, the
coupling constants between these P atoms and the dppm
or phosphine ligands are consistent with the proposed
structures.
Electr on -Don or P r op er ties of th e Un sa tu r a ted
Clu ster s 10. Compound 10b reacts instantaneously
with HBF4‚OEt2 in dichloromethane solution to give the
blue cationic cluster [Mn2Au2(µ3-H)(CO)6(µ-dppm){P(p-
tol)3}2]BF4 (13). Spectroscopic data for 13 are almost
identical with those for [Mn2Au2(µ3-H)(CO)6(µ-dppm)-
(PPh3)2]PF6, an unsaturated cluster prepared upon
addition of [AuPPh3]+ to the trinuclear hydride cluster
[Mn2Au(µ-H)(CO)6(µ-dppm)(PPh3)] and characterized
through an X-ray study mentioned above.11 This struc-
ture is derived from that of clusters 10 by formally
adding a proton to one of the Mn2Au faces, on the side
closer to the bridging dppm (Chart 7). Of course, it is
reasonable to assume that initial attack of H+ occurs
first on the side opposite the dppm bridge, and then the
hydride rearranges upward, which implies the bending
of one of the Mn2Au triangles away from dppm. This
possibly removes some of the steric congestion imposed
by a flat Mn2Au2 skeleton. In addition, we recall that
this metal skeleton is fluxional, as previously found for
the PPh3 analogue of 13,11 thus indicating that both the
H ligand and the Au-PR3 groups have substantial
mobility in these clusters.
The IR spectrum of 13 exhibits four CO stretching
bands that are 48 cm-1 higher on average than those
in the parent cluster 10b. This is expected and is
indicative of a substantial electron density flow away
from the dimanganese center, thus justifying our view
of this reaction as an acid (H+)-base (Mn2Au center)
interaction.
Rea ction of Com p ou n d 10b w ith Sn Cl2. Having
examined the reactions of clusters 10 with simple bases
(phosphines) and acids (HBF4‚OEt2), we then considered
the reactions with methylene and related metal frag-
ments. Taking into account the general isolobal rela-
tionships,28,29 reaction of a doubly metal-metal bonded
compound with such a fragment can be considered a
cyclopropanation-like reaction, which makes use of both
donor and acceptor properties of the multiple metal-
metal bond.
From a geometric point of view, the structure pro-
posed for isomers A is strongly related to those recently
determined for three electron-precise Mn-Au clusters
of general formula [Mn2Au(µ-PPh2)(CO)7(µ-L2)],27 in
which a diphosphine ligand (L2) bridges one of the Mn-
Au edges of the Mn2Au triangle, so that it occupies an
equatorial position in the coordination sphere around
manganese.
As stated above, reaction of compounds 10 with tedip
give first a blue intermediate which could not be
isolated. Its IR and low-temperature 31P NMR spectra,
however, are similar to those of compounds 11; there-
fore, we trust that this intermediate is just an unstable
isomer of the final clusters isolated. This unstable
intermediate then evolves in two different ways, one
leading to the tetranuclear clusters 11 and a second one
leading to the trinuclear clusters 12. The latter reaction
can be represented through eq 1.
[Mn2Au2(CO)5(µ-dppm)(PR3){µ-(EtO)2POP(OEt)2}] +
CO f “Au{µ-OP(OEt)2}” + 12 (1)
The formation of 12 would perhaps be initiated by an
intramolecular P-O bond oxidative addition of tedip to
yield bridging phosphide (P(OEt)2) and phosphonate
(28) (a) Hoffmann, R. Angew. Chem., Int. Ed. Engl. 1982, 21, 711.
(b) Stone, F. G. A. Angew. Chem., Int. Ed. Engl. 1984, 23, 89.
(29) Adams, R. D. In Comprehensive Organometallic Chemistry, 2nd
ed.; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.; Pergamon:
Oxford, U.K., 1995; Vol. 10, Chapter 1.
(27) Lee, K. H.; Low, P. M. N.; Hor, T. S. A.; Wen, Y.-S.; Liu, L. K.
Organometallics 2001, 20, 3250.

Manganese-Gold and -Silver Mixed-Metal Clusters
Organometallics, Vol. 22, No. 22, 2003 4507
F igu r e 2. Molecular structure of compound 14 (left) and its projection along the Mn-Mn bond (right; CO ligands omitted
and only C-P atoms of phosphine ligands shown for clarity). Ellipsoids represent 30% probability.
Diazomethane indeed reacts rapidly with 10b, but
this gives a mixture of complexes, which could not be
separated or characterized. On the other extreme, no
reaction was observed between 10b and [Fe2(CO)9], the
latter being a common source for the 16-electron frag-
ment Fe(CO)4. This possibly has an steric origin, as the
iron fragment might be too large for an already crowded
dimanganese center. We then examined the reaction of
10b with SnCl2, a much smaller metal analogue of
methylene.
Compound 10b reacts slowly with SnCl2 in tetrahy-
drofuran to give the pentanuclear cluster [Mn2Au2SnCl2-
(CO)6(µ-dppm){P(p-tol)3}2] (14) in good yield. No inter-
mediate species could be detected during this slow
reaction. The IR spectrum of 14 (Table 1) exhibits five
strong CO stretching bands with a frequency average
similar to that of 10b. This suggests that the incoming
SnCl2 fragment is not behaving as a pure donor or
acceptor but possibly in both ways, as expected for a
methylene-like metal fragment. However, the pattern
of the CO bands in 14 is quite different from those for
common [Mn2(µ-X)(µ-Y)(CO)6(µ-L2)] hexacarbonyl com-
plexes, thus suggesting a considerable structural re-
organization upon reaction, as confirmed through an
X-ray study (Figure 2 and Table 2).
The structure of 14 exhibits a nearly planar raft-like
pentanuclear Mn2Au2Sn array with the tin atom as the
common vertex of the three (Mn2Sn or MnAuSn) metal
triangles (maximum deviations from the mean plane are
0.101(7) Å for Mn(1) and 0.106(6) Å for Mn(2), on
opposite sides). The diphosphine ligand bridges the Mn-
Mn edge almost perpendicularly to this plane, and three
carbonyls complete a distorted-octahedral environment
around each Mn atom. The chloride ligands are bound
to the tin atom and lie in a plane perpendicular to the
Mn2Au2Sn array. As for 10b, consideration of 3c-2e
bonds in the two MnSnAu triangles, with the corre-
sponding orbitals pointing to the center of these tri-
angles, leads to a regular description of the coordination
geometry around the metal atoms, it being octahedral
(Mn), tetrahedral (Sn), or linear (Au).
clusters [Mn2Au(µ-Br)(CO)6(µ-tedip)(PPh3)] (3.090(3)
Å)24 and [Mn2Au(µ-PPh2)(CO)8(PPh3)] (3.066(8) Å)30 but
similar to the Mn-Mn length in the also saturated
[Mn2(µ-SnPh2)2(CO)6(µ-tedip)] (3.1045(5) Å).31 The Mn-
Au (2.651(7) and 2.654(6) Å) and Mn-Sn (2.602(7) and
2.600(7) Å) distances for 14 are similar to those in the
aforementioned clusters. On the other hand, the Sn-
Au lengths in 14, 2.813(4) and 2.815(4) Å, are compa-
rable to that of 2.881(1) Å found in [(PMe2Ph)2AuSnCl3]32
and are thus possibly indicative of a rather weak Sn-
Au bonding interaction. Finally, we should note the
presence of a weak interaction of the Au atoms with the
carbonyls lying on the metal plane, as revealed by the
relatively short Au-C separations of 2.53(4) and 2.63(6)
Å (Table 2).
The metal skeleton in 14 is rather unusual. Hetero-
metallic clusters with planar skeletons are rare, and
most of the known examples involve transition metals
and group 11 elements.7,9 In fact, to the best of our
knowledge, compound 14 represents the first example
of a pentanuclear raft-type heterometallic cluster having
tin in the metal skeleton. The closest analogue of 14
would possibly be represented by the tetranuclear
cluster [Os3(µ-SnCl2)(µ-CH2)(CO)11], a compound formed
by insertion of SnCl2 into one of the Os-Os bonds in
[Os3(µ-CH2)(µ-CO)(CO)10].33 Indeed, the formation of 14
can be understood as an insertion of SnCl2 into an Mn-
Au bond in 10b, followed by rearrangement of the
second AuPR3 unit in order to bridge a Mn-Sn bond.
Recalling the isolobal relationships in the pairs H/
AuPR3 and CH2/SnCl2, the first step is completely
analogous to the methylene insertion into the unsatu-
rated Os2(µ-H)2 moiety of [Os3(µ-H)2(CO)10] (Scheme
1).34 The second step, which would lead to a coordinated
methane molecule at the dimetal center, is not spon-
taneous in the triosmium system. We have previously
shown, however, that these rearrangements conform to
(30) Iggo, J . A.; Mays, M. J .; Raithby, P. R.; Henrick, K. J . Chem.
Soc., Dalton Trans. 1984, 633.
(31) Carren˜o, R.; Riera, V.; Ruiz, M. A.; J eannin, Y.; Philoche-
Levisalles, M. J . Chem. Soc., Chem. Commun. 1990, 15.
(32) Clegg, W. Acta Crystallogr. 1978, B34, 278.
(33) Viswanathan, N.; Morrison, E. D.; Geoffroy, G. L.; Geib, S. J .;
Rheingold, A. L. Inorg. Chem. 1986, 25, 3100.
(34) (a) Calvert, R. B.; Shapley, J . R. J . Am. Chem. Soc. 1977, 99,
5225. (b) Calvert, R. B.; Shapley, J . R. J . Am. Chem. Soc. 1978, 100,
7726.
The Mn-Mn length (3.171(9) Å) is ca. 0.3 Å longer
than that in 10b, as expected upon changing the formal
bond order from 2 to 1. This value is somewhat greater
than those for the related electron-precise trinuclear

4508 Organometallics, Vol. 22, No. 22, 2003
Liu et al.
material (Aldrich, neutral, activity I). Low-temperature chro-
matographic separations were carried out using jacketed
columns refrigerated by a closed 2-propanol circuit kept at the
desired temperature with a cryostat. NMR spectra were
recorded at 300.13 MHz (1H), 121.50 MHz (31P{1H}), and 75.47
MHz (13C{1H}), at room temperature unless otherwise stated.
Chemical shifts (δ) are given in ppm, relative to internal TMS
(1H, 13C) or external 85% H3PO4 aqueous solution (31P), with
positive values for frequencies higher than that of the refer-
ence. Coupling constants (J ) are given in Hertz. 13C{1H} NMR
spectra were routinely recorded on solutions containing a small
amount of tris(acetylacetonato)chromium(III) as a relaxation
reagent. Occasionally, non-deuterated solvents were used, in
which case a coaxial capillary containing D2O was immersed
into the solution, to adjust and maintain the homogeneity of
the magnetic field. This is indicated as (solvent/D2O).
Sch em e 1. F or m a tion of Clu ster 14 in
Com p a r ison w ith Oth er In ser tion Rea ction s of
Un sa tu r a ted Dim eta l Cen ter sa
P r ep a r a t ion of Tet r a h yd r ofu r a n Solu t ion s of Li-
[Mn 2(µ-H)(CO)6(µ-d p p m )] (2). In a typical experiment, a THF
solution (10 mL) of the dihydride [Mn2(µ-H)2(CO)6(µ-dppm)]
(0.033 g, 0.05 mmol) was treated with Li[BHEt3] (50 µL of a 1
M solution in THF, 0.05 mmol), and the mixture was stirred
for 30 min, yielding a dark brown solution which was then
ready for further use. 31P and 1H NMR spectra indicate the
a
Only the reactive centers are shown for clarity (see text).
presence of compound 2 as the major species in this air-
1
sensitive solution. H NMR (THF/D2O): δ -11.2 (t, br, J PH
28, µ-H).
)
a rather subtle balance of factors. Thus, the zinc
derivatives of [Mn2(µ-H)2(CO)6(µ-tedip)] adopt a methyl-
like geometry for L ) tetrahydrofuran but a methane-
like arrangement for L′ ) Me2N(CH2)2NMe2 (Scheme
1).10a
P r ep a r a tion of Tetr a h yd r ofu r a n Solu tion s of Na [Mn 2-
(µ-H)H2(CO)6(µ-d p p m )] (2). In a typical experiment, a THF
solution (10 mL) of the dihydride [Mn2(µ-H)2(CO)6(µ-dppm)]
(0.035 g, 0.053 mmol) was stirred with an excess of Na[BH4]
(ca. 0.02 g) for 30 min to give a yellow solution, which was
filtered using a cannula and was then ready for further use.
Alternatively, the solvent can be removed from the yellow
solution, the residue extracted with dichloromethane, and the
extract filtered through diatomaceous earth. Removal of
solvent under vacuum from this filtrate gave a yellow powder
that was washed with petroleum ether. This air-sensitive solid
was shown by 1H NMR to retain a considerable amount of
THF. 1H NMR (CD2Cl2): δ 7.50-6.50 (m, 20H, Ph), 3.54 (t,
J PH ) 14, 2H, CH2), -13.98 (s, br, 3H, Mn-H).
P r ep a r a tion of Tetr a h yd r ofu r a n Solu tion s of Na 2[Mn 2-
(CO)8(µ-d p p m )] (4). In a typical experiment, a THF solution
(10 mL) of [Mn2(CO)8(µ-dppm)] (0.072 g, 0.1 mmol) was stirred
at room temperature with an excess of a 0.6% Na amalgam
(ca. 0.5 mL) to give an air-sensitive orange-brown solution,
which was filtered using a cannula and was then ready for
further use.
Con clu d in g Rem a r k s. Anions 1 and 2 are valuable,
and in some cases unique, synthetic precursors for
electron-deficient manganese-silver and -gold clusters
having Mn2M or Mn2M2 skeletons. These are formally
derived through replacement of bridging H by MPR3
units in the parent unsaturated dihydride [Mn2(µ-H)2-
(CO)6(µ-dppm)]. This substitution increases considerably
the electron-donor ability of the dimanganese center
while retaining some of the reactivity derived from its
electron deficiency, best shown through the reaction
with the carbene-like fragment SnCl2. However, con-
siderable crowding is apparent in these tetranuclear
Mn2M2 clusters; therefore, their reaction with simple
P-donor ligands results in substitution of peripheral
ligands or more complex transformations, rather than
leading to simple addition processes.
P r ep a r a tion of [Mn 2H2(CO)8(µ-d p p m )] (5). An excess of
H3PO4 (0.05 mL of an aqueous 85% solution) was added to a
THF solution of anion 4 prepared as described above from 0.1
mmol of starting material, and the mixture was stirred for 5
min to give a yellow solution. Solvent was then removed under
vacuum, the residue was extracted with the minimum amount
of dichloromethane, and the extract was chromatographed on
alumina (activity III). Elution with dichloromethane/petroleum
ether (1/6) gave a yellow fraction which yielded, after removal
of solvents under vacuum, compound 5 as a yellow microcrys-
talline powder (0.059 g, 82%). Anal. Calcd for C33H24Mn2O8P2:
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All manipulations and reactions
were carried out using standard Schlenk techniques under an
atmosphere of dry, oxygen-free nitrogen. Solvents were puri-
fied according to standard literature procedures35 and distilled
under nitrogen prior to use. Petroleum ether refers to that
fraction distilling in the range 60-65 °C. The compounds
[Mn2(µ-H)2(CO)6(µ-dppm)],13a [Mn2(CO)8(µ-dppm)],19 [AgCl-
(PCy3)]4,36 and [AuCl(PR3)] (R ) Ph, p-tol)37 were prepared
according to literature procedures. Tetrahydrofuran solutions
of Na2[Mn2(CO)6(µ-dppm)] were prepared in situ as described
in ref 2 and used assuming a 100% yield. Other reagents were
obtained from the usual commercial suppliers and used
without further purification. Filtrations were carried out using
a cannula or, more generally, through diatomaceous earth, and
aluminum oxide (alumina) for column chromatography was
deactivated by appropriate addition of water to the commercial
1
C, 55.02; H, 3.36. Found: C, 54.55; H, 3.10. H NMR (C6D6):
δ 7.43 (m, 8H, Ph), 6.85 (m, 12H, Ph), 3.84 (t, J PH ) 8, 2H,
CH2), -7.26 (false d, AA′XX′ multiplet, |J PH + J PH′| ) 40, 2H,
Mn-H).
P r ep a r a tion of [Mn 2Ag(µ-H)(CO)6(µ-d p p m )(P Cy3)] (6).
Solid [AgCl(PCy3)]4 (0.021 g, 0.05 mequiv) was added to a THF
solution containing ca. 0.05 mmol of compound 2, prepared in
situ as described above and cooled to 0 °C, and the mixture
was stirred and allowed to reach room temperature over 20
min to yield a blue-violet solution. Solvent was then removed
under vacuum, the residue was extracted with the minimum
amount of dichloromethane, and the extract was chromato-
graphed at -20 °C on an alumina column (activity IV). Elution
(35) Perrin, D. D.; Armarego, W. L. F. Purification of Laboratory
Chemicals; Pergamon Press: Oxford, U.K., 1988.
(36) Cariati, F.; Naldini, L. Gazz. Chim. Ital. 1965, 95, 201.
(37) Braunstein, P.; Lehner, H.; Matt, D. Inorg. Synth. 1990, 27,
218.

Manganese-Gold and -Silver Mixed-Metal Clusters
Organometallics, Vol. 22, No. 22, 2003 4509
with dichloromethane/petroleum ether (1/3) gave a blue frac-
tion. Removal of solvents from that fraction yielded compound
6 as a blue-violet microcrystalline powder (0.030 g, 57%). Anal.
Calcd for C49H56AgMn2O6P3: C, 55.96; H, 5.37; Found: C,
56.30; H, 5.50. 1H NMR (CD2Cl2, 233 K): δ 7.75-6.65 (m, 20H,
Ph), 4.10, 3.83 (2 × m, 2H, CH2P), 1.80-0.90 (m, 33H, Cy),
-20.6 (t, J PH ) 25, µ-H).
temperature for 1 h. Solvent was then removed under vacuum,
the residue was extracted with the minimum amount of
dichloromethane, and the extract was chromatographed on an
alumina column (activity III) at -30 °C. Elution with dichloro-
methane/petroleum ether (1/3) gave an orange fraction, which
after removal of solvents yielded compound 12a (0.012 g, 24%)
as an orange microcrystalline powder. Elution with a 3/1
solvent mixture gave a blue-violet fraction which gave analo-
gously compound 11a as a blue-violet microcrystalline powder
(0.037 g, 62%). Anal. Calcd for C56H57Au2Mn2O10P5 (11a ): C,
P r ep a r a tion of [Mn 2Au (µ-H)(CO)6(µ-d p p m ){P (p-tol)3}]
(7). The procedure is completely analogous to that described
for 6, except that [AuCl{P(p-tol)3}] (0.027 g, 0.05 mmol) was
used instead. After chromatographic purification, compound
7 was obtained as a blue-violet microcrystalline powder (0.032
g, 55%). Anal. Calcd for C52H44AuMn2O6P3: C, 53.63; H, 3.81;
43.43; H, 3.71; Found: C, 42.95; H, 3.42. Anal. Calcd for C53H47
-
AuMn2O8P4 (12a ): C, 51.21; H, 3.81; Found: C, 50.75; H, 3.48.
1H NMR (11a , CD2Cl2): δ 7.60-6.80 (m, 35H, Ph), 4.30-3.50
(m, 10H, CH2 and OCH2), 1.39, 1.35, 1.34, 1.22, 1.16, 1.06
(complex, 6 × t, 12H, Me); this corresponds to a mixture of
isomers A and B in a 1:2 ratio (by 31P NMR, see discussion
and Table 3). 1H NMR (12a , CD2Cl2): δ 7.80-6.55 (m, 35H,
Ph), 4.22 (q, J HH ) J HP ) 7, 2H, OCH2), 4.02 (cd, J HH ) 7, J HP
) 6, 2H, OCH2), 3.53 (dt, J HH ) 12, J HP ) 10, 1H, CH2), 2.41
(cd, J HH ) J HP ) 12, J HP ) 6, 1H, CH2), 1.46, 1.36 (2 × t, J HH
) 7, 2 × 3H, Me).
1
Found: C, 53.49; H, 4.00. H NMR (CD2Cl2): δ 7.65-6.70 (m,
32H, Ph and p-tol), 3.68, 3.36 (2 × c, J PH ) J HH ) 10, 2 × 1H,
CH2), 1.97 (s, 9H, Me), -20.74 (t, J PH ) 24, 1H, µ-H).
P r ep a r a tion of [Mn 2Au (µ-H)(CO)7(µ-d p p m ){P (p-tol)3}]
(8). Carbon monoxide was gently bubbled through a THF
solution (10 mL) of compound 7 (0.030 g, 0.025 mmol) at room
temperature for 30 s, and the mixture was further stirred for
10 min to give a brown solution. Solvent was then removed
under vacuum and the residue dissolved in toluene and
crystallized from toluene/petroleum ether at -20 °C to give
compound 7 as a brown microcrystalline powder (0.020 g, 60%).
Anal. Calcd for C53H44AuMn2O7P3: C, 53.37; H, 3.72; Found:
C, 53.91; H, 3.38. 1H NMR (CD2Cl2): δ 7.62-7.05 (m, 32H,
Ph and p-tol), 3.87 (t, J PH ) 10, 2H, CH2), 2.43 (s, 9H, Me),
-5.43 (dt, J PH ) 92, 18, 1H, µ-H). 13C{1H} NMR (CD2Cl2, 213
K): δ 231.0 (s, br, 1 × CO), 229.5 (m, br, 2 × CO), 227.0 (m,
Rea ction of Com p ou n d 10b w ith ted ip . The procedure
is completely parallel to that described above, but with
compound 10b (0.060 g, 0.036 mmol) used instead. After a
similar workup, compounds 11b (0.035 g, 72%) and 12b (0.009
g, 20%) were obtained as blue-violet and orange microcrystal-
line powders, respectively. Anal. Calcd for C59H63Au2Mn2O10P5
(11b): C, 44.54; H, 3.99; Found: C, 45.00; H, 4.12. Anal. Calcd
for C56H53AuMn2O8P4 (12b): C, 52.35; H, 4.16; Found: C,
1
br, 4 × CO), 142.7 (C4(p-tol)), 138.0, 137.0 (2 × false t, |J CP
+
52.01; H, 3.85. H NMR (11b, 400.13 MHz, CD2Cl2): δ 7.55-
J CP′| ) 40, 2 × C1(Ph)), 134.3-128.4 (p-tol and Ph), 126.4 (d,
J CP ) 57, C1(p-tol)), 50.2 (t, J CP ) 20, CH2), 22.0 (s, Me).
P r ep a r a tion of [Mn 2Ag2(CO)6(µ-d p p m )(P Cy3)2] (9). Solid
[AgCl(PCy3)]4 (0.045 g, 0.106 mmol) was added to a tetra-
hydrofuran solution (10 mL) containing ca. 0.053 mmol of 1
at -80 °C, and the mixture was stirred and allowed to reach
room temperature for 20 min. Solvent was then removed under
vacuum from the dark blue solution, and the residue was
dissolved in a minimum amount of dichloromethane and
chromatographed on an alumina column (activity III) at -20
°C. A Blue fraction was collected by elution with dichloro-
methane/petroleum ether (1/5). Removal of solvents from the
latter under vacuum gave compound 9 as a blue-violet micro-
crystalline powder (0.052 g, 68%). Anal. Calcd for C67H88Ag2-
Mn2O6P4: C, 55.93; H, 6.16; Found: C, 55.52; H, 5.93. 1H NMR
(CD2Cl2, 218 K): δ 7.70-7.10 (m, 20H, Ph), 5.24 (t, J HP ) 10,
2H, CH2), 1.90-1.15 (m, 66H, Cy).
6.65 (m, 32H, Ph and p-tol), 4.20-3.40 (m, 10H, CH2 and
OCH2), 2.20 (s, C6H4Me, isomer A), 2.18 (s, C6H4Me, isomer
B), 1.28, 1.07, 1.00 (3 × t, 2:1:1 relative intensity, J HH ) 7,
OCH2CH3, isomer B), 1.282, 1.27, 1.14 (3 × t, 2:1:1 rel int,
J HH ) 7, OCH2CH3, isomer A). Ratio A:B ) 2:3. 1H NMR (12b,
CD2Cl2): δ 7.60-6.50 (m, 32H, Ph and p-tol), 4.21(q, J HH
)
J HP ) 7, 2H, OCH2), 4.02 (cd, J HH ) 7, J HP ) 6, 2H, OCH2),
3.54 (dt, J HH ) 12, J HP ) 10, 1H, CH2), 2.44 (s, 9H, C6H4Me),
2.37 (m, 1H, CH2), 1.46, 1.35 (2 × t, J HH ) 7, 2 × 3H,
OCH2CH3).
P r ep a r a tion of [Mn 2Au 2(µ-H)(CO)6(µ-d p p m ){P (p-tol)3}2]-
BF 4 (13). A dichloromethane solution (10 mL) of compound
10b (0.045 g, 0.027 mmol) was treated with HBF4‚OEt2 (8 µL
of an 85% solution in Et2O, ca. 0.04 mmol), and the mixture
was stirred for 5 min. Solvent was then removed under
vacuum and the residue washed with toluene (3 × 3 mL) to
give compound 13 as a dark blue microcrystalline solid (30
mg, 63%). Anal. Calcd for C73H65Au2BF4Mn2O6P4: C, 50.02;
H, 3.74; Found: C, 49.65; H, 3.52. 1H NMR (CD2Cl2): δ 7.57-
7.08 (m, 44H, Ph and p-tol), 4.06 (t, J HP ) 12, 2H, CH2), 2.15
(s, 18H, Me), -18.05 (tt, J HP ) 33, 22, 1H, µ-H).
P r ep a r a tion of [Mn 2Au 2(CO)6(µ-d p p m )(P P h 3)2] (10a ).
The procedure is completely analogous to that described for
9, except that [AuCl(PPh3)] (0.052 g, 0.11 mmol) was used
instead. After chromatographic purification (elution with
dichloromethane/petroleum ether (1/3)) compound 10a was
obtained as a blue microcrystalline powder (0.058 g, 70%).
Anal. Calcd for C67H52Au2Mn2O6P4: C, 50.90; H, 3.32; Found:
C, 51.42; H, 3.62. 1H NMR (CD2Cl2): δ 7.70-6.90 (m, 50H,
Ph), 4.87 (t, J HP ) 9, 2H, CH2).
P r epar ation of [Mn 2Au 2(CO)6(µ-dppm ){P (p-tol)3}2] (10b).
The procedure is completely analogous to that described for
10a , except that [AuCl{P(p-tol)3}] (0.060 g, 0.11 mmol) was
used instead. In this way compound 10b was obtained as a
dark blue microcrystalline solid (0.064 g, 72%). Anal. Calcd
for C73H64Au2Mn2O6P4: C, 52.66; H, 3.87; Found: C, 52.17;
H, 3.87. The crystals used in the X-ray study were grown by
slow diffusion of petroleum ether into a toluene solution of the
complex, at room temperature. 1H NMR (CD2Cl2): δ 7.70-
6.90 (m, 44H, Ph and p-tol), 4.88 (t, J HP ) 10, 2H, CH2), 2.40
(s, 18H, Me).
P r epar ation of [Mn 2Au 2Sn Cl2(CO)6(µ-dppm ){P (p-tol)3}2]
(14). Solid SnCl2 (0.006 g, 0.032 mmol) was added to a
tetrahydrofuran solution (10 mL) of compound 10b (0.045 g,
0.027 mmol), and the mixture was stirred at room temperature
for 12 h to give an orange mixture. Solvent was then removed
under vacuum, and the residue was chromatographed on an
alumina column (activity IV) at -30 °C. An orange fraction
was collected by eluting with dichloromethane/petroleum ether
(1/1). Removal of solvents from the latter gave compound 14
as an orange microcrystalline powder (0.038 g, 76%). Anal.
Calcd for C73H64Au2Cl2Mn2O6P4Sn: C, 47.28; H, 3.48; Found:
C, 47.30; H, 3.77. The crystals used in the X-ray study were
grown by slow diffusion of petroleum ether into a tetrahydro-
1
furan solution of the complex at room temperature. H NMR
(CD2Cl2): δ 7.60-6.65 (m, 44H, Ph and p-tol), 3.86 (dt, J HH
)
14, J HP ) 9, 1H, CH2), 3.47 (dt, J HH ) 14, J HP ) 12, 1H, CH2),
2.41 (s, br, 18H, Me).
Rea ction of Com p ou n d 10a w ith ted ip . A tetrahydro-
furan solution of compound 10a (0.065 g, 0.041 mmol) was
stirred with tedip (10 µL, 0.041 mmol) at 0 °C for 5 min to
give a black-blue solution, which was further stirred at room
X-r a y Str u ctu r e Deter m in a tion for Com p ou n d s 10b
a n d 14‚1/2THF . Crystals of compound 10b and of the THF
solvate of 14 were obtained by crystallization from toluene/

4510 Organometallics, Vol. 22, No. 22, 2003
Ta ble 4. Cr ysta llogr a p h ic Da ta for 10b a n d 14‚1/2THF
Liu et al.
10b
14‚1/2THF
C75H68Au2Cl2Mn2O6.5P4Sn
empirical formula
C
73H64Au2Mn2O6P4
fw
1664.94
1890.58
temp (K)
293(2)
293(2)
wavelength (Å)
0.71073
0.71073
cryst syst, space group
a (Å)
triclinic, P1h
12.048(5)
triclinic, P1h
10.839(8)
b (Å)
12.364(5)
16.735(9)
c (Å)
25.136(9)
85.38(2)
78.45(2)
67.29(2)
3384(2)
2, 1.634
4.832
1636
23.697(11)
102.75(2)
97.19(2)
100.27(2)
4064(4)
2, 1.545
4.393
1844
R (deg)
â (deg)
γ (deg)
V (Å3)
Z, calcd density (Mg m-3
)
abs coeff (mm-1
F(000)
)
cryst size (mm)
θ range for data collecn (deg)
index ranges
0.35 × 0.20 × 0.15
3.03-25.01
-13 e h e 14, -14 e k e 14,
0 e l e 29
11 797/11 797
11 797/0/335
1.274
0.0587, 0.1599
0.2702, 0.2620
5.559 and -2.339
0.25 × 0.20 × 0.15
3.03-22.67
0 e h e 9, -15 e k e 17,
-22 e l e 23
2234/2234
2234/20/338
1.052
0.0501, 0.1166
0.0501, 0.1166
0.916 and -1.998
no. of rflns collected/unique
no. of data/restraints/params
goodness of fit on F2
final R indices (I > 2σ(I)) (R1, wR2)a
R indices (all data) (R1, wR2)a
largest diff peak and hole (e Å-3
)
GOF ) [∑[w(Fo - Fc2)2]/(n - p)]1/2. R1 ) ∑||Fo| - |Fc||/∑|Fo|. wR2 ) [∑[w(Fo - Fc2)]/∑[w(Fo2)2]]1/2. w ) 1/[σ2(Fo2) + (aP)2 + bP], where
a
2
2
P ) [max(Fo2,0) + 2Fc2]/3.
petroleum ether and tetrahydrofuran, respectively, and crys-
tals of suitable size were mounted on a Philips PW 1100
diffractometer with graphite-monochromated Mo KR radiation
(λ ) 0.710 73 Å). The data were collected at 293 K for both
compounds. Crystallographic and experimental details are
summarized in Table 4. A semiempirical method of absorption
correction was applied (maximum and minimum values for
the transmission coefficient were 1.000 and 0.907 (10b) and
1.000 and 0.732 (14‚1/2THF)).38 No decay for 10b but a decay
of 18% was observed during the data collection for 14‚1/2THF.
The structures were solved by direct methods (SIR97)39 and
non-hydrogen atoms were refined anisotropically for 10b
whereas for 14‚1/2THF only Au, Mn, Sn, P, and Cl atoms were
refined in this way. In 14‚1/2THF two molecules of tetra-
hydrofuran, with an occupancy factor of 0.25, were found;
moreover, two phenyl rings of the dppm ligand were found
disordered in two positions with an occupancy factor of 0.5.
All the hydrogen atoms were introduced from geometrical
calculations and refined using a riding model.
Ack n ow led gm en t. We thank the Ministerio de
Educacio´n y Ciencia and the Ministerio de Asuntos
Exteriores of Spain for a grant (to X.-Y.L.) and the
MECD and MCYT of Spain (Projects PB96-0317 and
BQU2000-0944) for financial support.
refined by least squares against Fo (10b) and Fo (14‚1/2THF)
2
(SHELXL-97),40 using the WinGX software package.41 All the
(38) (a) Walker, N.; Stuart, D. Acta Crystallogr., Sect. A 1983, 39,
158. (b) Ugozzoli, F. Comput. Chem. 1987, 11, 109.
(39) Altomare, A.; Burla, M. C.; Camalli, M.; Cascarano, G. L.;
Giacovazzo, C.; Guagliardi, A.; Moliterni, A. G. G.; Polidori, G.; Spagna,
R. J . Appl. Crystallogr. 1999, 32, 115.
(40) Sheldrick, G. M. SHELX97: Programs for Crystal Structure
Analysis (release 97-2); University of Gottingen, Gottingen, Germany,
1997.
Su p p or tin g In for m a tion Ava ila ble: Tables of fractional
atomic coordinates, anisotropic thermal parameters, and bond
lengths and angles for compounds 10b and 14. This material
is available free of charge via the Internet at http://pubs.acs.org.
(41) Farrugia, L. J . J . Appl. Crystallogr. 1999, 32, 837.
OM0304614