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Crystal Structure of the 1-Allyl-Grignard Compound Bis(allylmagnesium chloride-TMEDA).

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(the adduct possesses a center of symmetry) P'.,,~= 1.45 g cm ', p = 4 1
cm I , 3620 independent observed reflections [IFJ 23o(lFJ), H 5 0 " ] ,
R =0.03 I. R,. =0.032. All hydrogen atoms were obtained from a A F m a p
and these groups refined as rigid bodies. The P e ions in
[Pt(NH,),-(Z),][PF,.j, are disordered and were relined as two distinct
orientations of occupancies 0.65 and 0.35. Data were measured on a Nicolet R3m diffractometer using the o-scan routine with graphite monochromated CuKicradiation. In both cases, the structures were solved by
the heavy atom method and empirical absorption corrections were applied. Both rtructures were refined anisotropically. Further details of the
crystal structure investigation can be obtained from the Cambridge
Crystallographic Data Centre, University Chemical Laboratory, Lensfield Road, Cambridge CB2 IEW (England). Any request should be accompanied by the full literature citation for this communication.
E.xperimenta1: [Pt(NH,),. I][PF&: A solution of I (7.3 mg, 0.013 mmol)
and [Pt(NH,)JPF& (7.2 mg, 0.013 mmol) in MelCO/EtOH ( I ml) was
filtered and Et,O was layered o n top until a faint permanent precipitate
was observed After 24 h, colorless crystals, suitable for X-ray investigation. were obtained of the I : I adduct 16. I mg. 42%, m.p. 238-242°C with
decomposition, m / r (positive-ion FABMS), 970 for [M - P e l o . IPt(NH,),.(Z),][PF,,I,. A solution of 2 (6.2 mg, 0.01 mmol) and
[Pt(NH3),][PF,,], (5.6 mg, 0.01 mmol) in CHlC12/Me2C0 ( I ml) was filtered and E t 2 0 was layered on top until a faint permanent precipitate
was observed. After 24 h, colorless crystals, suitable for X-ray investigation, were obtained of the 2 : I adduct [m.p. 238-242'C with decomposition].
I n both independent complexes, the polyether components of the macrorings display the a a g - a ag+ a a conformation from CI to C9 and
from C15 to C23 observed (21 in [Rh(cod)(NH&. l]? The only major
differences in the receptor conformations of the two independent complexes are in the torsional geometries of the central polyether chains
from C32 to 039. In [Pt(NH>),. I]", there is an a g + a ago-a ag'a conformation from 0 3 0 t o 0 3 9 whereas the analogous polyether chain in
[Rh(cod)(NH.,)?. 1lQ reads o g ~ a a g ' a a g - a .
R. 0. Could, A. M. Gray, P. Taylor, M. D. Walkinshaw, J Am. Chem.
Soc. 107 (1985) 5921.
S. K. Burley, C. A. Petsko, Science 229 (1985) 23: J . Am. Chem. Soc. I08
(1986) 7995.
A. M Z. Slawin, N. Spencer, J. F. Stoddart, D. J. Williams, J. Chem. Suc.
Chem. Commun. 1987. in press.
Recalling the fact that 2,2,3,3,1I.I 1,12,12-octamethyl-1,4,7,10,13,16-hexaoxacyclooctadecane adopts an all-gauche conformation when it forms
a I :2 adduct with 2 equivalents of BH,NH, (D. R. Alston, J . F. Stoddart. J. B. Wolstenholme, B. L. Allwood, D. J. Williams, Tetrahedron 41
(1985) 2923), there is no apparent reason why the central polyether
chain in the [Pt(NH,),.(2)l]'o dication (Fig. 3) should exist in a different conformation from that observed (Fig. I ) for the [Pt(NH,),. I]" dication. Interestingly, in C D K O C D , solution at low temperatures
(T'= -70°C). the singlet observed in the 'H-NMR spectrum for the methyl protons in (Pt(NH3)4.Z][PF,]l separates ( A v = 3 0 Hr) into two equal
intensity signals. T h e rate constant of 67 s - ' calculated at the coalescence temperature (T,) corresponds to a ACT value of 10.0 kcal mol- '.
We have ascribed this temperature-dependent behavior tentatively to
hindered rotation about the C34-C35 bond of the pinacol unit in an
otherwise conformationally-symmetrical polyether chain.
Crystal Structure of the
q'-Allyl-Grignard Compound
Bis(al1ylmagnesiurn chloride-TMEDA)**
By Michael Marsch, Klaus Harms, Werner Massa, and
Gernoi Boche*
Although allyl-transition-metal complexes['' and, more
recently, also allyllithium compound^^^-^^ have been studied in the solid state, the determination of the crystal structure of an allyl-Grignard compound has thus far not been
reported. Herein we report on the crystal structure of
bis(al1ylmagnesium chloride-TMEDA) 1 (TMEDA = tetramethyleth ylenediamine).
[*] Prof. Dr. G. Boche, M. Marsch, Dr. K. Harms,
Priv.-Doz. Dr. W. Massa
Fachbereich Chemie der Universitat
Hans-Meerwein-Strasse, D-3550 Marburg (FRC)
I**]This work was supported by the Fonds der Chemischen lndustrie and
the Deutsche Forschungsgerneinschaft (SFB 260).
696
0 VCH V e r l a g i g c . ~ e l l . ~ ~mhH.
lia~
0-6940 Weinheim. 1987
The allylmagnesium chloride-TMEDA complex formed
on treatment of allylmagnesium chloride in tetrahydrofu-
ran (THF) with TMEDA crystallizes as the dimer l.['."]
The two allylmagnesium chloride-TMEDA units are coupled via a Mg-CI-Mg-CI four-membered ring in which the
Mg-CI and Mg-CI' distances are markedly different
(240.0( 1) pm and 269.4( 1) pm, respectively).
R
d
Fig. I . Crystal structure of 1 . I he atoms are represented by spheres with
arbitrary radii. Selected bond lengths [pm] and angles ["I: Mg-CI 240.0(1),
Mg-CI' 269.4(1), C9-Mg 217.9(3), CIO-Mg 300.5(3), Mg-NI 228.5(2), Mg-N4
221.1(2), C9-CIO 144.2(4), CIO-CI I 133.5(4); Mg-C9-C10 I10.5(2), C9-CIOC I I 130.2(3), H9A-C9-H9B I09(2), HI IA-CI I-HI I 6 I19(2), C9-CIO-HIOA
I l4( I),CI I-CIO-H IOA I I 5 5( 1.3, C 10-CI I-H I IA l23.6( l.6), CIO-CI I-H I I B
117.3( L6), CI-Mg-CI' 84.69(3), Mg-CI-Mg' 95.32(3), CI-Mg-CY 125.29(7), N1Mg-C9 99.26(8), N I - M g ~ N 4 80.28(7). C I - M g ~ N 4 107.18(6), CI'-Mg~N4
87.84(5); torsion angle ["I: C I I-CIO-C9-Mg - 109.2(3), C1 I-CIO-C9-H9A
14(1), Cll-CIO-C9-H9B 138(1).
The characteristic feature of 1 is the q'-allyl-magnesium
bond. The C9-Mg distance is 217.9(3) pm and thus lies in
the range of C-Mg distances in alkyl-Grignard comp o u n d ~ . " There
~
should be no bonding between C 10 and
Mg (300.5(3) pm). From the size of the CIO-C9-Mg angle
( I lOS(2)") and of the torsional angle C1 I-ClO-C9-Mg
( - 109.2(3)") it follows that the Mg atom juts out significantly from the allyl-CCC moiety. As a consequence H9A
and H9B are twisted "inwards".
In contrast to the Grignard compound 1, in many allyltransition-metal
and in (1,3-diphenylallyllithium-diethyl ether), 2,[31one finds $-structures; allyllithium-pentamethyldiethylenetriamine3 contains at least a
markedly unsymmetric $-(if not an q'-)allyl-lithiurn
bond.I4' Comensurate with the ql-structure of 1 the C-C
distances in the allyl moiety are different: CIO-Cll
133.5(4) pm and C9-C10 144.2(4) pm. The C9-ClO-Cll angle is noticeably widened (130.2(3)") and reaches almost
the size of the CCC angles in the allyllithium compounds 2
(131(1)")[31and3 (131.5(3)0).f4JThe bond angles at C9 correspond to tetrahedral geometry and those at C1 1 to trigonal geometry (see caption to Fig. 1). The hydrogen atoms
HlOA, H l l A , and H l l B lie in the C9-CIO-ClI plane.
An q'-structure in allyl-Grignard compounds in solution
had been concluded earlier by Roberts et al. from their
classical NMR investigations.'x' The proof for such a structure was furnished by Schlosser and Stahle by means of the
isotope-perturbation method.'"' Benn and Rujinska et al.
confirmed the q'-structure with "Mg-NMR data'"] and
0570-0833/87/0707-0696 $ 02.50/0
Angew Chem. Int. Ed. Engl. 26 11987) No. 7
'J("C,"C) coupling constants.["'] Ab initio calculations on
("gasmus") allylrnagnesium hydride also favor a n q I-
structure.'"] Marked deviations from the solid-state structure of 1 are found in the C9-CIO bond length, which is
149.9 instead of 144.2(4) pm, and in the location of the Mg
atom, which according to the calculations assumes a position representing "a compromise between a "classical"
geometry and a bridged structure."["l
Summary: The structure of 1 in the solid state should
serve as a good model for the structure of allyl-Grignard
compounds in solution and as a criterion for further calculations.
Received: April 13, 1987 [ Z 2203 IE]
German version: Angew. Chem. 99 (1987) 706
CAS Registry numbers:
1 , 109013-41-4: TMEDA, 110-18-9; allylmagnesium chloride, 2622-05-1.
[I] Important works: a) G. Wilke, 8 . Bogdanovic, P. Hardt, P. Heimbach,
W. Keim, M. Kroner, W. Oberkirch, K. Tanaka, E. Steinriicke, D. Walter, H. Zimmermann, Angew. Chem. 78 (1966) 157; Angew. Chem. Inr.
Ed. Engl. 5 (1966) 151; b) R. Uttech, H. Dietrich, 2. Krista(1ogr. 122
(1965) 60; c) U. Franke, E. Weiss, J . Organomel. Chem. 139 (1977) 305;
d ) J. A. Kaduk, A. T. Poulos, J. A. Ibers, ibid. 127 (1977) 245 (in this
work the structures of many allyl-transition metal complexes are discussed); e ) T. H. Tulip, J. A. Ibers, J. Am. Chem. SOC. 101 (1979) 4201; f)
D. M. P. Mingos in G. Wilkinson, F. G. A. Stone, E. W. Abel (Eds.):
Comprehensive Orgonometallic Chemistry. Val. 3, Pergamon, Oxford
1982, p. 1 ; g) T. H. Cymbaluk, R. D. Ernst, V. W. Day, Organomerallies 2
(1983) 963; h) R. Benn, A. Rufihska, ibid. 4 (1985) 209, and references
cited therein; i) R. Goddard, C. Kriiger, F. Mark, R. Stansfield, X.
Zhang, 'hid. 4 (1985) 285, and references cited therein; j) P. W. Jolly,
Angeu. Chem. 97 (1985) 279: Angew. Chem. Inr. Ed. Engl. 24 (1985)
283.
[2] H. Koster, E. Weiss, Chem. Eer. 115 (1982) 3422.
[ 3 ] G. Boche. H. Etzrodt, M. Marsch, W. Massa, G. Baum, H. Dietrich, W.
Mahdi. Angew. Chem. 98 (1986) 84; Angew. Chem. Inr. Ed. Engl. 25
(1986) 104
[4] U. Schumann, E. Weiss, H. Dietrich, W. Mahdi, J. Organomer. Chem.
322 (1987) 299.
151 Preparation: 2 mL of a 2.0 M solution of allylmagnesium chloride in
T H F (Aldrich) was treated with 2 m L of TMEDA (13.3 mmol) at 20°C.
The colorless crystals of 1 can be isolated after 12 h (yield 100%).
161 X-ray structure analysis: 150 K, colorless crystals ca. 0.5 x 0.4 x 0.6 mm',
P2,/n, a=844.5(1), b= 1102.0(1), c=1350.4(1) pm, @=92.58(1)", 2 = 4 ,
p',,,cc,
= I . 148 g cm -.'. 3254 reflections measured (Enraf-Nonius CAD4
four-circle diffractometer, MoKCcradiation), 1353 of which, with
F,,> 3o(F,,)after Lp correction and averaging of equivalent reflections,
were used for the calculations. Solution by direct methods, anisotropic
refinement of all non-hydrogen atoms. The H-atoms on TMEDA were
refined to calculated positions (C-H 96 pm) according to a riding model
with common temperature factors for the CH2- and CH,-hydrogen
atom$. the H-atoms at C9, CIO, and C1 I calculated first, then isotropically refined with fixed C-H distances (96 pm). R=0.035, R,, =0.037
=02(F)+0.0005F', 152 parameters. Further details of the
with
crystal structure investigation are available o n request from the Fachinformationszentrum Energie, Physik, Mathematik GmbH, D-7514 Eggenstein-Leopoldshafen 2 (FRG), o n quoting the depository number CSD52424, the names of the authors, and the journal citation.
[7] Examples: a) ethylmagnesium bromide. 2diethyl ether, C-Mg 2 15(2)
pm; L J. Guggenberger, R. E. Rundle, J . Am. Chem. Soc. 90 (1968)
5375; b ) bis(ethy1magnesium bromide-triethylamine)2, C-Mg 218 pm; J.
Toney. G. D. Stucky, Chem. Commun 1967. 1168.
[XI a) J. E. Nordlander, J. D. Roberts, J . Am. Chem. Soc. 8/ (1959) 1769; b)
G. M. Whitesides, J. E. Nordlander, J. D. Roberts, Discuss Faroday Soc.
34 (1962) 185; c) J Am. Chem. Soc. 84 (1962) 2010; d) diallylmagnesium: H. E. Zieger, J. D. Roberts, J. Org. Chem. 34 (1969) 1976; e) D.
Leibfritz, R. 0. Wagner, J. D. Roberts, Justus Liebrgs Ann. Chem. 763
( 1972) I73 191.
[91 See also: D. A. Hutchison, K. R. Beck, R. A. Benkeser, 1. B. Grutzner,
J. Am. Chem. Soc. 95 (1973) 7075.
[ 101 a ) M. Schlosser, M. Stahle, Angew. Chem. 92 (1980) 497; Angew. Chem.
I n / Ed Enyl. 19 (1980) 487: b) M. StPhle, M. Schlosser, 1. Orgonomet.
Cliem. 220 (198 I ) 277.
[ I I ] R. Benn, H. Lehmkuhl, K. Mehler, A. Rufihska, Angew Chem. 96 (1984)
52 I ; Angen. Chem. I n / . Ed. Engl. 23 (1984) 534.
1121 T. Clark. C. Rohde, P. von R. Schleyer, Organometallics 2 (1983) 1344.
Anger.. Chmnz. In!. Ed Engl. 26 11987) No. 7
Dinuclear Fulvalene Complexes of Tri- and
Tetravalent Zirconium**
By Wolfgang A . Herrmann,* Tomas Cuenca,
Babil Menjon, and Eberhardt Herdtweck
The high reactivity of organozirconium(r1i) compounds,
which also includes extreme sensitivity to air, has hitherto
precluded a systematic development of this class of compounds comparable to that of organotitanium(ir1) compounds, whose chemistry is very well documented.['.*' In
view of the importance of low-valent organozirconium
species in catalytic processes".'] we have directed our attention to the synthesis of polynuclear systems of this type
exploiting the fulvalene bracketing effect and have recently reported on the zirconium(l1r) derivative 1, a complex which is readily accessible by reductive CC-coupling
of zirconocene dichloride with ~ o d i u r n . ' ~We
' have now
also succeeded in carrying out the directed methylation
and oxidation of this derivative, thus opening up the possibility of further functionalization.
Reaction of 2.1 molar equivalents of methyllithium with
1 in the complete absence of air, moisture and light leads
to formation of the chlorine-free methylation product 2 , a
red solid, in 65% yield; N M R spectroscopic data ( ' H , "C)
show that 2 is formed as a cidtrans-mixture 2a + 2b."'
2 is one of the few unequivocally characterized alkyl
compounds of trivalent zirconium;".*] it can be stored
without decomposition for prolonged periods of time only
in the absence of light and oxygen at temperatures below
-20°C. The directed solid-state thermolysis of pure 2
(2OO0C/15 minlvacuum) yields chiefly methane as gaseous cleavage product (94%) together with small amounts
of ethane, propane, propene and cis-2-butene. This finding
can be explained in terms of initial formation of an unstable ZrCHzZr species, which continuously decomposes like
other p-methylene complexes.'"]
Moreover, owing to its ready oxidizability, 1 can for example be converted in good yields (80-90%) into the CC[*] Prof. Dr. W. A. Herrmann, Dr. T. Cuenca, Dr. B. Menjon,
Dr. E. Herdtweck
Anorgdnisch-chemisches lnstitut der Technischen Universitat M unchen
Lichtenbergstrasse 4, D-8046 Garching (FRG)
[**I Chemistry of Oxophilic Transition Metals, Part 3. This work was supported by the Alexander-von-Humboldt-Stiftung (T. C. and B . M.)and
by Hoechst Aktiengesel1schaft.-Part 2: [4c].
0 V C H Verlagsgesell.~chajim b H . 0-6940 Weinheim. 1987
OS70-0833/87/0707-0697 $ 02.50/0
697
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crystals, ally, structure, compounds, tmeda, grignard, bis, allylmagnesium, chloride
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