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Complexes with an 2-2-SiO Bridge. Structure of the Bimetallic Complex

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these investigations to compounds of type 11 whose R group
is suitable for affinity labeling of the ATPase.
Received: June 2. 1989 [Z 3372 IE]
German version: AngeK. Clirm. 101 (1989) 1417
2x10-3 N
5 min
Fig. 1 . Positive inotropic effect of I t a (two concentrations) o n a guinea-pig
papillary muscle. The bracketed regions represent times during which the muscle was bathed in solution containing l l a (bathing fluid, Tyrode solution
mol L - ' KCI and 1.8 x 1W'mol L - ' CaCI,; pH 7.4,
containing 2.7 x
35 C ) . The contractions were induced by square-wave electrical pulses (stimulus potential. twice the threshold potential; pulse duration 4 ms; frequency,
1 .2 H r ) and recorded with a mechano-electrical transducer (Endevco. model
8107-20) on a recorder (Schwarzer Physiopolygraph Varioscript; units in Newton).
[I] E. M. Price, J. B. Lingrel. Biochemisrri. 2 7 (198X) 8400- 8408. and references cited therein.
[2] a) Review: D. G . Allen. D. A. Eisner, S. C. Wray, Nururc iLondunl 316
(1985) 674-675; b) recent pharmacological studies: 1. Yamahara. S.
Tanaka. H. Matsuda, T. Sawada, H. Fujimura, Nippon Yukirriyrrkrr Z f d t f
88 (1986) 413-423.
[3] Earlier investigations of photoaffinity labeling: a) B. M. Anner, B~oc~hcrit.
J.227(1985)l-ll.andreferencescitedtherein: b)T. Deffo. D . S . Fullerton, M. Kihara, R. H. McParland. R. R. Becker, B. M . Simat. A. H.
From. K . Ahmed. M. 1. Schimerlik. Bioc/zcmr.stry 22 (1983) 6303- 6309. c )
K. Ahmed, R. McParland. R. Becker, A. From. D. S Fullerton, Fed.
Proc., Fed. Am. Soc. E.vp. Bid. 46 (purr 31 (19x7) 19x3.
141 H. W. Hoppe, M. Kaiser. D. Miitlei-. P. Welrel. Tetruhethon 43 (1987)
2045- 2057.
151 D . Seebach. M. Kolb, B.-T. Grobel, Clwni. Ber. 106 (1973) 2277 2290.
[6] M. Bednarski, S. Danishefsky. J. Am. Chem. Soc. 105 (19x3) 3716- 3717;
S. J. Danishefsky, W. H. Pearson, J. Orx. Chcm. 48 (1983) 3865 3866: S.
Castellino, J. J. Sims. Teiruh(&on L<.rt.25 (1984) 2307 2310. M . M . Midland, R. S. Graham. J. Am. C h ( m So<. i06 (1Y84) 4294-4296.
[7] Alternative preparation of IOa. H.-W. Hoppe. B. Stammen. U . Wcrner. H.
Stein. P. Welrcl, Trctruhrdron 45 (1989) 3695 3710.
IS] Related investigations of the synthesis of enol lactones: S. E. Denmark.
J. A. Sternbcrg. J1 Am. Clieni. Soc. 108 (1986) 8271~-8279:K. Vogt. R . R.
Schmidt, Tetrohrdron 44 (1988) 3271 3280.
[9] ' H , I3C N M R , ' H I ' H COSY. 'H/13C COSY. NOE difference spectra,
' H I ' H decoupling experiments
[to] H:W. Hoppe, P. Welzel. 7ttruhedron Lerr. 27 (1986) 2459 2462. and references cited therein.
[ l l ] E . A . Braude. Annn. Rep. Prog. Chem. 42 (1945) 105-130: J. D. Willel.
J. R. Grunwell, G. A. Berchtold, J. Org. Chent. 33 (196X) 2297- 2302.
[121 Detailed discussion of this problem: U . Werner. H.-W. Hoppe. P.W e l d .
G . Snatzke, R. Boese, Tetruhrdron 45 (1989) 1703 -1710.
1131 P. E. Hammann. G. G . Habermehl, Z. Nurur/or.dI. 8 4 2 (1987) 781 -782.
114) E. J. Corey. 1. Szekely, C. S. Shiner, TEtrultethn Lett. iY77. 3529 -3532;
E.J. Corey, K . Narasaka, M . Shibasaki, J. .4m. C h r / ~ iSo<.
98 (1976)
641 7 - 6418.
[15] B.-T. Grobel, D. Seebach. Svnrhesis 1977. 357-402.
[16] H. G. Glitsch, H . Pusch, T. Schumacher, F. Verdonck. PfTiigcr.! A d z . 3Y4
(1982) 256 -263.
[17] I. S. Cohen. N. B. Datyner, G. A . Gintant, N. K. Mulrine, P. Pennefather.
J1 Pliy.c.iol. (London) 383 (1987) 251-267.
to that during the preceding control period; the abscissa
gives the logarithmic concentrations of 11a and 12. The linear parts of the curves reveal that I 1 a i s less active than 12
by a factor of 10. Spontaneous activity of 12 (toxic effect) is
mol L-', whereas
observed at a concentration of 5 x
l l a shows no toxic effect at a concentration of
mol L-'. Increasing the extracellular K O concentration leads to a rightward shift of the two doseeresponse
curves (not shown). Similar results were obtained with two
other papillary muscles.
c [ m o l L-'I
Fig. 2. Dose response curves of the positive inotropic effect of steroids 11 a
and 12 ( 0 )o n a guinea-pig papillary muscle. Ordinate: contractile force ( T )
relative to the contractile force of muscle during the preceding control period
( T J . Abscissa: concentrations (logarithmic). Note that the numbers 5 on the
5 x lo-', and 5 x
abscissa stand for 5 x
) .1
Compound I l a also inhibits the NaO pump current of
sheep Purkinje fibers (measured as described previously["])
in a dose-dependent fashion: At I l a concentrations of
5 x lo-*. 1 x lo-', and 5 x TO-' mol L - ' , the transient outward (pump) current decreased by 27.5, 38.6, and 62%, respectively. Apparently, 11 a is active on sheep Purkinje fibers
at lower concentrations than those required for guinea-pig
papillary muscle, in agreement with similar results obtained
for three cardiac glycosides.['
The results described here show that 22,23-dihydrobufalin
11 a exhibits the characteristic pharmacological properties of
cardioactive steroids: it displays positive inotropic activity
and inhibits active Na@/K@transport. We plan to extend
Atigmr. Ch(~m.Inr.
Ed. EngI. 28 (i98Y) N o . 1 0
Complexes with an q2-p2-Si0 Bridge.
Structure of the Bimetallic Complex
1 0 - ~ IFe(CO), (p-Si(OMe),OMe)(p-dppm)PdCl](Fe-Pd)**
By Pierre Braunstein,* Michael Knorr, Antonio Tiripicchio.
and Murisa Tiripicchio CameNini
Interest in the synthesis and study of molecular clusters
having iron-palladium bonds largely stems from their still
relatively small number"] and their successful use as precursors of Si0,-supported heterogeneous catalysts, in particular
Dr. P. Braunstein, Dr. M. Knorr
Laboratoire d e Chimie de Coordination UA 416 C N R S
Universiti Louis Pasteur
4 rue Blaise Pascal, F-67070 Strashourg Cedex (France)
Prof. A. Tiripicchio, Prof. M. Tiripicchio Camellini
Istituto di Chimica Generale ed Inorganica
Universiti di Parma, Centro di Studio per la Strutturistica
Diffrdttometrica del C N R
Wale delle Scienze. 1-43100 Parma (Italy)
Financial support from the C N R S (Paris). CNR (Rome), the "Commission of the European Communities" (Contract No. S T 2 J - 0 3 4 7 - 0 and
the Deutsche Forschungsgemeinschaft (to M.K.) are gratefully acknowledged.
V C H Vcr/ugsxcellsthaft mhH. D-6Y40 Weinhctm,i989
for highly selective reductive carbonylation reactions.f2I
Moreover, there is a renewed interest in the chemistry of
silicon-containing transition-metal compounds.[31 In attempts to combine these two facets, we have sought to prepare Pd-Fe-Si systems and report here the first complexes in
which a siloxy ligand acts as an q2-p2-Si0 bridge between
two metal centers, thus forming novel MM'SiO four-membered ring structures.
Reaction of the mer hydrido complex 1I4] with
[PdCI,(PhCN),] in toluene was expected to afford a bimetallic complex resulting from HCI elimination and dppm-assisted metal-metal bond formation [Eq. (a)] (dppm = bis(dipheny1phosphino)methane). In addition, the structure of the
P -P
trans-[ PdCI,(PhCN),]
1Si(\ c o
The Fe atom in 2 has an octahedral environment which
retains the trans-P-Fe-Si arrangement found in the precursor. The square-planar geometry about the Pd atom is
achieved by oxygen coordination of one of the Si-OMe
groups (the O(4) atom deviates by 0.1 14(5) A from the mean
plane passing through the Pd, Fe, P(2), C1, and O(4) atoms).
The PdFeSiO(4) four-membered ring is almost planar (the
Pd-Fe-Si-0(4) torsion angle is 1.5(2)") and nearly coplanar
with the P(l)FeP(2)Pd moiety, the dihedral angle between
the two mean planes being 3.8(1)").
Reaction of the trigonal-bipyramidal anion 3 with
[PdCI,(PhCN),], [PdCI,(PPh,),J, or [PdCl,(dppm)] also
leads to 2. In the latter case, it is noteworthy that no bisdppm complex was formed.[51 The entropically favored
intramolecular qz-p2-Si0bridge formation wins over intermolecular nucleophilic displacement by a donor ligand such
as C O (acetone, 20 min) or PPh, at room temperature. The
Fe-Pt complex 4, analogous to 2, was prepared according to
Equation (b).
trons-[PtClz(PhCN)2 1
M e/ O PP
P np
product 2, fully elucidated by X-ray diffraction methods,
shows an unprecedented q2-pz-siloxy bridging ligand
(Fig. 1).
In solution, Pd-0 dissociation readily occurs in 2, as
shown by the presence of only one signal for all nine OMe
protons in the ' H N M R spectrum. The Pt-0 bond in 4 is less
labile and two signals are observed for the methoxy protons
in a 2:1 ratio, the latter resonance showing coupling with
phosphorus (4JpH
= 2.5 Hz).
The oxidative addition reaction of the Fe-H bond of 1 to
PtO, shown in Equation (c), affords the hydrido bimetallic
complex 5, in which there is no evidence for a Pt-0 interaction. Spectroscopic data support the structure drawn.
The new q2-p2-Si0 bonding mode presented here opens
the possibility of using the "hemilabile" behavior of the
%(OR), ligand in solution for the stabilization of unsaturated, catalytically active polynuclear systems. It also provides
Fig. I . Perspective view of the molecular structure or2. Selected bond lengths
angles [ I : Fe-Pd 2.582(1), Fe-P(1) 2.241(2). Fe-Si 2.275(2), Fe-C(1)
1.758(5). Fe-C(2) 1.776(7). Fe-C(3) 1.782(6). Pd-P(2) 2.185(1). Pd-C1 2.303(2).
Pd-0(4) 2.100(4). Si-0(4) 1.659(4). Si-015) 1.630(6), Si-0(6) 1.627(5): Pd-FeP(1) 100.4(1), Pd-Fe-C(l) 162.1(2). Pd-Fe-C(2) 77.8(2), Pd-Fe-C(3) 71.5(2),
Pd-Fe-Si 76.2(2), CI-Pd-P(Z) 94.0(1), P(Z)-Pd-Fe 90.6(1). 0(4)-Pd-Fe 79.7(1),
CI-Pd-0(4) 95.3(1). Pd-O(4)-Si 103.2(2), 0(4)-Si-Fe 100.8(2).
[A] and
(Ph3P) P-t
Si (OMe),
Angew. Clzem. Inr. Ed. Engl. 28 itY89) No. I0
a new structural model for the bonding of small metal clusters OK aggregates onto silica, a dominant theme in heterogeneous catalysis.'2". 2b. 61 The additional bonus in dealing with
heterometallic systems is further exemplified here by their
ability to display selective metal-hgand interactions.
E.uprrimental Procedure
Satisfactory elemental analyses were ohtained for all new compounds. ' H
N M R signals of phenyl protons not given. 2: Method A : A mixture of
[PdCI,(PhCN),] (384 mg, 1 mmol) and 1 (646 mg, 1 mmol) in 40 mL of toluene
was atirred a t - 20 C for I h. The solution became dark red at room temperature. After solvent evaporation to ca. 10 mL under reduced pressure. 2 precipitated as a red-orange powder. Addition of ca. 40 mL of hexane completed the
precipitation. Filtration and recrystallization from CH,Cl,/hexane gave
378 mg ( 4 8 % ) of 2 as red crystals. IR (nujol) t(CO)[cm-']: 1988 m, 1928 s.
1905 \. FT IR (polyethylene): i.(PdCl)[cm-'] = 270. 'H N M R (200 MHr,
[D,,]acclone. TMS, 20 C): 6 = 3.74 (s. YH, OMe), 4.36 (I. 2 H . CH,,
'./(PHI = 11 Hz). " P ( ' H j NMR(81.02 MHz,C,D,/CH,C1,.20 C):AXspin
system. O A = 34.9 (d. P(Pd). J(PP) = 58 Hz); 6, = 48.0 (d. P(Fe)).
2: Method B: .4 solution of K . 3 (688 mg. 1 mmol) in 20 mL of T H F was added
dropwise a t - 40 C t o a suspension of [PdCI,(PPh,)J (701 mg, I mmol) in
25 m L ofTHF. Upon slowly warming to room temperature. the solution turned
dark red. After 10 h agitation, the solution was filtered (to remove KCI) and
concentrated to ca. 5 mL under reduced pressure. Complete precipitation of 2
was achieved by addition of hexane. PPh, was eliminated by extraction with
Et,O hexane Yield: 810 mg (68%).
4: A solution of K . 3 (685 mg, 1 mmol), prepared by the reaction of 1 with K H
in T H F (for the PPh, analogue. see Ref. 171). in 20 mL of T H F was added
dropwise ( I h) at room temperature to a suspension of[PtCI,(PhCN),] (472 mg,
1 mmol) in 30 m L of T H E After stirring for 12 h, the dark red solution was
filtered (to remove KCI) and concentrated to ca. 10 mL under reduced pressure.
Addition of 40 mL of hcxane induced precipitation of 4 as a yellow-brown
powder. Subscquent recrystallizations from CH,Cl,/pentane afforded yellow
microcrystals 01' 4. Yield: 210 mg (24%). IR(THF) a(CO) [cm-'1
= I995 m. 1938 s. 1910 m, sh. ' H NMR (200 MHz. [D,]acetone, TMS, 20 C):
h = 3.74 (s, 6H. Si(OMe),), 3.80 (d, 3H. PI-OMe, ,J(PH) = 2.8 Hz). 4.04 (t
with Iq5Pl satellites. 2 H . CH,, 'J(PH) = 11. ,J(PtH)= 66Hz). ' H N M R
(200 MH7. C,D,. TMS, 20"C): 6 = 3.25 (t. 2 H . CH,, 'J(PH) = 11 Hz). 3.74
(s. 6 H . Si(OMe),). 3.90 (d, 3 H , Pt-OMe, ,J(PH) = 2.8 Hz). " P ( ' H J N M R
(81.02 MHL, [D,]acetone. 20°C). 6 = 7.7 (d with '"Pt satellites, P(Pt),
J(PP) = 47 Hz. 'J(PPt) = 4756 Hz). 82.9 (d, P(Fe)).
5 : A solution of (Pt(C,H,)(PPh,),] (751 mg, 1 mmol) in 20 m L of toluene was
allowed to react at room temperature with successive fractions of 1 (total
646 mg. I mmol). Each time, gas evolution was noted. At the end of the reaction
(ca. 0.5 h, I R monitoring). the yellow solution was concentrated to ca. 5 mL.
20 m L of hcxane was added. and the colorless precipitate of 5 was washed with
Et,O.'hexane to remove free PPh,. Yield: 905 mg (82%). Compound 5 may he
recrystallired from CH,Cl,/hexane IR(KBr): f(PtH)[cm-l] = 2149 w.
IR(CH,CI,): C(CO)[cm-'] = 1968 m, 1900 s, 1870 s. ' H N M R (200 MHz,
CD,CIZ. TMS, 20 C): 6 = 4.51 (dt with '"Pt satellites, 1 H. PtH. 2J(P,ro.,H)
= 197.6. 'J(PH) = 13.9 'J(PtH) = 686Hz). 3.56 ( s , YH, OMe), ca. 3.8 (2H.
CH,, overlapping with O M e signal). 3 i P { ' H i N M R (81.02 MHz. C,D,/
toluene. 20 C ) : ABX spin system: 6 = 29.4 (d with ly5Pt satellites, P(Pt),
J[PP(Fc)] = 130. './(PIP) = 2074 Hz). 32.0 (t with Iy5Pt satellites, PPh,,
'J(PP) = 10. 'J(PtP) = 3478 Hz). 72.2 (dd with Iq5Pt satellites P(Fe),
J(pp) = 130.10. 'J(PtP) = 88 Hz).
C r w u l struc/uri' rkterininution .f2: monoclinic, CZic, Z = 8. u = 24.644(8),
h = lS.X39(8), c = 17.798(5) A, 3! = 112.95(2)' ; V = 6396(4) A'; M, = 787.32;
Q ' ~ , ~ ,=
, 1.635 gem-,; F(000) = 3184, p(MaK,) = 12.69cm-'. Siemens A E D
diffractometer. 0 20 scan technique and Nh-filtered Mo,, radiation
(L = 0.71073 A). 3 < 0 < 28 ', 6075 unique reflections. 3722 observed with
I > 20(0. The structure was solved by Patterson and Fourier methods and
refined by the full-matrix least-squares method with anisotropic thermal
parameters for all non-hydrogen atoms. The SHELX system ofcomputer programs was uscd ( G .M. Sheldrick, Progruin.for C r w u l Slrucrure Derwmmurioii,
Cambridge 1976). Some hydrogen atoms were clearly located and refined
isotropically. the others were placed at their geometrically calculated positions
and introduced i n the final structure-factor calculation with fixed isotropic
thermal parameters. R = 0.0285, R , = 0.0354. Further details of the crystal
structure ;inalysis may be obtained from the Fachinformationszentrum Karlsruhe, Geseilschaft Eur wissenschaftlich-technische Information mhH. D-7814
Eggenstein-Leopoldshafen2 (FRG) o n quoting the depository number CSD54012, the names of the authors, and the journal citation.
Received: May 30, 1989 [Z 3363 IE]
German version: Anyex.. Chem. I01 (1989) 1414
[ l ] a) M. I . Bruce, J. Orpnomrt. Chem. Lihr. 17(1988) 399: b) P. Braunstein.
C. de Meric de Bellefon, M. Ries, J. Fischer. Orgunnmetuflics 7 (1988) 332:
G. B. Jacobsen. B. L. Shaw. J1 Chrm. Snc.. Dalton Truns. 1987, 2005.
[2] a) P. Braunstein, J. Rose in I. Bernal (Ed.): Strrrochi,~ni.s/r~,
( I / OrgununictulIic und lnorgunii, Cuiiipoiind.s, Vol. 3. Elsevier. Amsterdam 1989. in press: b)
B. C Gates. L. Guczi. H. Knozinger (Eds.): Mrrul Clusro..\ in ('ural~.s/s.
Elsevier. New York 1986: c) P. Braunstein. J. Kervennal. J:L. Richert.
.4ngeiv. C h m i i . 97 (1988) 762; Angciv. Chem. Int. EN'. Engl. 34 (1985) 768: d )
P. Braunstein, R. Devenish. P. Gallezot, B. T. Hcaton. C. J. Humphreys. J.
Kervennal. S. Mulley, M. Ries. M. ihiil. 100 (1988) 972 and 27 (19x8) 927.
[3] a) K. M. Mackay, B. K. Nicholson in G. Wilkinson, F. G. A. Stone. E. W.
Ahel (Eds.) . Coinprchensiw Orgunomrrallii~Clieinisrr~,Pergamon. Oxford
1982.chapter43: h)U.Schubert,J.Or~ii~ioiner.
Zybill, Nuchr. Ch~n?.
z ~ hLuh.
. 37(1989) 248: d ) T. D. Tilley i n 8. Pat;ii. Z.
Rappoport (Eds.): The Chmni.s/r). o/ Orgunu SiIicon C o n ~ ~ ~ o r nWiley.
New York 1988. chapter 26; e) J. Powell. J. F. Sawyer. M. Shifiilian.
8 (1989) 877.
[4] P. Braunstein, M. Knorr. U. Schubert. unpublished.
181 P. Braunstein, N. Guxrino. C. de Meric de Bellefon. J.-L. Richert. An,qen..
C h m . 99 (1987) 77; Angaiv. Chem. I n / . Ed. Engl. 26 (1987) 88.
[6] a ) S. J. Tauster. Acc. Chjlnn. Ros. 20 (1987) 389: b) R. T. K. Baker. S. J.
Tauster. J. A. Dumesic, Strong M(,rul-Siippurl Inrerrrr //on.\ / 1986) ACS
Si,inp. So.. 298.
[7] U. Schubert, E. Kunz. M. Knorr. J. Miiller. Chi,in. Bar. 130 (19x7) 1079.
Two Novel Polyoxomolybdates Containing the
(MONO),@Unit: [Mo,N~(NO)O,,(OCH,),]~'
and [MO,(NO)O,,]~~
By Pierre Gouzerh,* Yves Jeannin, Anna Proust,
and Francis Roberr
The chemistry of polyoxometalates is under active investigation because of their use for imaging in metal oxide surface
chemistry. A few organopolyoxomolybdate derivatives
structurally related to [ M O , ~ , , ['I] ~with
~ a terminal 0x0
group replaced by a nitrogen-ligated group such as a diazenido, hydrazido, imido, o r nitrido ligand have been recently reported."] A number of d i n ~ c l e a r , [ tetran~clear,[~'
and o c t a n ~ c I e a r [ diazenidomolybdenum
species are also
known. Despite the obvious analogy between RNF and
NOo161and extensive studies of the reaction of hydroxylamine with oxomolybdenum compounds,~'~ nitrosyl
derivatives of polyoxomolybdates were hitherto unknown.
The reductive nitrosylation of oxomolybdenum complexes
was found to produce either m o n o n ~ c l e a r [ ' or
~ polynuclearrS1molybdenum(i1) complexes containing the MONO)^@
unit. Here we report the first polynuclear species containing
both (Mo"NO)~@and ( M O ~ ' O ) ~units.
,(NC-CH = CH-C(NHZ)NOJz] 1
Treatment of complex 1 191 with hydroxylamine in refluxing methanol and cooling the solution led to the formation
of violet crystals, which were identified as complex 2 by
chemical analysis and X-ray structure determination.fi0]The
crystals readily lose solvent. Their structure (cf. Fig. 1 )
derives from the Lindqvist structure. One MOO group is
missing and is replaced by a sodium cation interacting with
four terminal oxygen atoms of the polyanion and one methanol molecule. The linear MONO)^@ group is opposite to
sodium, and four methoxo ligands asymmetrically bridge
Mo" to its four MoV'neighbors. Formal molybdenum oxida[*] Prof. Dr. Y. Jeannin, Dr. P. Gouzerh, A. Proust, F. Robert
Lahoratoire de Chimie des Metaux de Transition
Universitk Pierre et Marie Curie
4 place Jussieu. 75252 Paris Cedex 05 (France)
This work was supported by the Centre National de la Recherche
Scien tifiq tie under con tract U RA 41 9.
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structure, complex, bimetallic, bridge, complexes, sio
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