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Base-Free Monomeric Organogallium Hydrides.

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purified by column chromatography (silica gel. CH,Cl,iethyl acetate 60: 1) to give
13a (60 mg. 30%) or 13b (120mg. 6 0 % ) .
14: Triketone 13 (16.0 mg, 38.6 pmol) was heated with 5 mL of diethylene glycol,
1 mL of hydrazine hydrate. and 50 mg of K O H at 140 ' C for 3 h and then at 210 -C
for 4 h . The reaction mixture was allowed to cool, 5 mL of water was added, and
the mixture was extracted with CHCI, (2 x 10 mL). Filtration through silica gel
(CHCI,) gave 14 (3.0 mg. 21 %).
Received: January 26. 1994 (Z6645IEI
German version: Angew. Chent. 1994, 106. 1326
[ I ] P Gund. T. M . Gund, J. Am. C h m ~SOC.
.
1981. 103, 4458-4465.
Base-Free Monomeric Organogallium
Hydrides * *
Alan H. Cowley,* Fransois P. Gabbai,
Harold S. Isom, Carl J. Carrano, and Marcus R. Bond
Information on neutral gallium mono- and dihydrides is quite
sparse."] Structurally characterized examples of such species are
confined to the dimers [Me,Ga(p-H)], ,[21 [H,Ga(p-CI)], ,[31
[H,Ga(p-NMe,)], ,[41 and [H,Ga(p-H),BH,]LS1and the novel
monomer [HGa(BH,),] with a pentacoordinate gallium
atom.['. '1 However, the recent detection of the tricoordinate
monomers GaHCI, and GaH,CI in argon matrices[81suggested
that monomeric organogallium hydrides might become isolable
if sufficiently bulky substituents were employed.
Treatment of [Ga(Ar)Cl,]['I
(Ar = 2,4,6-tBu,C,H2) with LiGaH, in Et,O at - 78 "C afforded
[2] Topol~igically nonplanar means nonplanar according to graph theory.
a) D M. Walba. Terruhedron 1985, 41. 3161-3212; b) F. Harary in Chemicd
Appli~utioii.~
o/ G r q h Thcjorj (Ed.: A. T. Bdlaban), Academic Press. London.
1976. Chaptei- 2: c ) J. Simon in Graph Theory rind To,no/og~~
in Chernisrr,~
(Eds.:
R. B. King. D. H. Rouvrdy). Elsevier. Amsterdam. 1987. p . 43.
[-?Ia ) 0. Ermrr, A s p k r i ~iwn Kru/r/e/II,.c,chnugi,n, Wolfgang Baur, Munchen.
1981. Chapter 4.6.3; b) W. Luef. R. Keese. H e h . Chin?.Acra 1987,70,543-553.
[4] L. A. Pnquette, R . A. Snow, J. L. Muthard. T. Cynkowski. J. Am. Chrm. SOC.
1978. 100, 1600- 1602.
[5] a ) D Kuck. A . Schuster. A n p w . Chrtn. 1988. 100, 1222-1224; Angew. Chem.
I n / . €d. D i g / . 1988, 37. 1192-1194; b) D. Kuck, A. Schuster, B. Paisdor, D.
Gestmiinn. unpublished.
a1.73
In%
theyield
CI mass
of colorless
spectrum
crystalline
of 1 the
\
[6] R Echrich. D. Kuck. Sj,i?/c,/t1993. 4, 344-347.
(71 a ) D. Kuck. .4.
Schuster, R. A. Krause. J. Org. Chem. 1991. 56, 3472-3475;
H
base
peak
appears
at
mjz
315
and
b) D. Kuck. A. Schuster. D. Gestmann. J. C/tem. SOC.Chern. Commrm. 1994,
corresponds to [Ga(Ar)H]' . This
609 - 61 0
assignment was confirmed by a
[XI a ) H E. Simmons 111. J. E. Maggio, Terruhedroii Lefr. 1981. 22. 287-290;
1
h) H . E Simmons 111. PhD Thesis, Harvard University, 1980; c) S. A. Benner.
high-resolution mass spectrum
I
A m . Chem. SOC.1981. 103, 1581-1582;
J. E. Maggio. H. E. Simmons 111, .
(HRMS).['OI The detection of a
d ) J E. Maggio. H. E. Simmons 111. ibid. 1981. 103, 1579-1581.
terminal GaH, moiety in the neutral molecule was evident from
[9] a ) L. A . Paquette. M. Vazeux, Tetruhedron Let/. 1981. 22, 291 294; b) L. A.
Paquette. R. V. Williams, M. Vazeux, A. R. Browne. J. Org. Chmt. 1984. 49,
the presence of infrared peaks in the terminal Ga-H stretching
2194-2197.
region (v, =I908 cm-'(sh), v,, =I887 cm-') and the relative
[lo] B. Pdiador. D. Kuck. J. Org. Chern. 1991, 56. 4753-4759.
intensities of the GaH, resonance and those of the aryl sub[ I l l R'e recently developed a third synthesis of 9; see ref. [5b,7b].
stituent in the 'H NMR spectrum.["] Moreover, the deshielded
[12] Three equivalents of 2-(trimethylsilyl)vinyhnagnesium bromide add to triketonc 6 in good yield; attempts to cyclize the resulting triptindantriol were not
position of the GaH, resonance (6 = 6.41) was suggestive of a
successful. B. Paisdor. Dissertation, Universitit Bielefeld, 1989.
base-free product since, for example, amine-gallane adducts ex[l?] All attempts at the oxidative removal of several benzene rings from 9 with the
hibit
hydride resonances in the range 6 = 4.5-5.0.["] The
goal of the conversion 9 + 2 (or 3) have failed so far; see ref. [5b].
monomeric nature of I was confirmed by an X-ray structure
[I41 For similar intramolecular additions see: J. S. Swenton, A. Callinan, S. Wdng.
J. Or:: Chcwt. 1992. 57, 78-85.
analysis.['*] Individual molecules of 1 (Fig. 1) reside on a crys[IS] a ) P A. Grieco. Aldrrchmircu Arru 1991, 24. 59-66; h) P. A. Grieco. J. D.
Clark. C . T. Jagoe. J. A m . Chen?. Soc. 1991, 113. 5488-5489.
[I61 a ) Examplesofthe thermalrearrangementofenolethersintoketones: S.Wang.
G W. Morrow. J. S. Swenton. J. Org. Chem. 1989, 54. 5364-5371, and references therein; b) 0-phenyl substitution of the enol ethers facilitates the [1.3]
rearrangement. see ref. [16a].
[I71 The marked upfield shift of the three orrho protons ofthe triptindan framework
of 13b (to d = 6.34) besides that of six orrho protons of the phenyl groups (to
b = 6.50) provides unequivocal proof of their "e.~o"orientation relative to the
perhydrotriquinacene unit.
[18] Centrosubstitiited triquinacenes: a) A. K. Gupta. G. S. Lannoye. G . Kubiak,
J. Schkeryantz.S. Wehrli. J. M. C0ok.J Am. Chem. SOC.1989. Iff. 2169-2179;
b) A. K. Gupta. U. Weiss. J. M. Cook. Tetrahedron Letr. 1988,2Y. 2535-2538;
c ) X . F u . 1 . M.Cook.J.Org.Cilet~?.1992,57,5121-5128;d)X.Fu,J.M.Cook,
fi~.trohedrlroriLcaft. 1990. 31. 3409-3412; e) B. Bengtson, Dissertation. Universitat Hamburg, 1986; f ) see also ref. [6]; g) X. Fu. J. M. Cook, Aldricliimicu
A1/11 1992, 25. 43-54
c12
[I91 Centrosubstituted trihenzotriquinacenes: a) A. Schuster, D. Kuck, Angew.
Chi,n?. 1991. 103. 1717-1720; Angew. Cheni.In/. Ed, Engl. 1991. 30. 16991702; b) D Kuck. T. Lindenthal. A. Schuster. Chrm. Ber. 1992. 125, 1449Fig. 1. View of 1 showing the atom labeling scheme. The tBu groups at C2 and C6
1460. and references therein.
are disordered and only the two highest occupancy methyl carbon atoms are shown.
I201 a ) D. M. Miiller. Chent. Werkbl. 1963.5Y, 334; h) R. B. Woodward, 7. FukunaThe hydrogen atoms on the gallium atom were not located. Selected distances [A]:
&a,R . C. Kelly. J . A m . Chern. SOC.1964.86.3162-3164;~) I. T. Jacohsen, A r m
Ga-Cl 1.942(7), Ga"'C8 and Ga..-C14
2.56(2).
Cheni.Scrmd. 1967. 21, 2235-2246.
[21] E Carceller. M. L. Garcia. A. hioyano, M. A. Pericds, F. Serratosa, TermherLon 1986. 42. 1831-1839.
[*] Prof. A. H. Cowley, F. P. Gahbal, H. S. Isom
[22] Reviews: a) Cugc Hydrocurhons (Ed.: G. A . Olah), Wiley, New York, 1990;
Department of Chemistry & Biochemistry
b) L. A. Paquette in [22a]. Chapter 9, pp. 331-335; c) W. D. Fessner, H.
The University of Texas at Austin
Prinzbach in [22al. Chapter 10. pp. 355-357; d) L. A. Paquette, Cltem. Rev.
Austin, TX 78712 (USA)
1989. XY. 1051 -1065; e) P. E. Eaton, Etruhedron 1979. 35. 2189-2223.
Telefax: Int. code (532)471-6822
[23] M. M. Midland. J. Org. Chrm. 1975, 40. 2250-2252.
Prof. C. J. Carrano, Dr. M. R. Bond
Department of Chemistry
Southwest Texas State University
San Marcos, TX 78666 (USA)
Telefax: Int. code + (512) 245-2374
[**I This work was supported by the National Science Foundation and the Robert
A. Welch Foundation.
,B"*G
+
An::ew
Chcnr In/. Ed. EnKI. 1994. 33, N o . I?
c:
VCH Verlagsgese//.schufimbH, 0-694.51 U'emheini, 1994
0570-0833194,'1212-1253 X 10.00+ .25!0
1253
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tallographic mirror plane located at y = 1/4 in the space group
P2,/m; there are 110 unduly short intermolecular contacts. The
[Bu groups at C2 and C6 are disordered about two orientations
which are related by 180" rotations around the C2-C7 and
C6-Ct3 bonds. Because of this disorder and weak scattering it
was not possible to locate the hydrogen atoms on gallium in the
Fourier difference map. The Ga-C bond length in 1 (1.942(7) A)
is virtually identical to that in [Ga(Ar)C12];191the G a . - . C8 and
G a . . C14 contacts are both short (2.56(2)
Compound 1
survives sublimation at 80°C
Torr); however, solutions of
I in benzene undergo rapid photolysis with 254 nm light to give
Ga", H,, and 1,3,5-tBu3C,H,.
The expected product of the reaction of [Ga(Ar),C1]['31 with
LiGaH, in Et,O at - 78 "C was the monohydride [Ga(Ar),H].
However, while peaks attributable to [Ga(Ar),H]+ and
[Ga(Ar),]+ were evident in the CI mass spectrum and a terminal
G a - H moiety was detected in the IR spectrum. the tBu and
aromatic C-H regions of the 'HNMR spectrum of 2 were
A).
2
ues for a terminal G a - H bond length involving tricoordinate
gallium. The Ga-H bond length in 2 (1.43(10)
may be compared with the range of bond lengths (1.487- 1.586 A) established
for tetra- and pentacooi-dinate species by gas-phase electron diffraction[2-61and the value of 1.527 8, for GaHCl, calculated by
ab initio methods!" The Ga-C(Ar) bond length in 2 (1.983(17)A)
is slightly longer than that in 1 (1.942(7)
ostensibly due to the
more sterically encumbered environment in the former. A further
point of structural interest relates to the short contacts between
the gallium atom and one of the hydrogen atoms on each of the
two ortko-tBu groups (Fig. 2). One of these distances (Ga(1). . .
H(63C) = 2.03(2)
is shorter than the other (Ga(1) . .
H(23A) = 2.28(2)
and the calculated position of H(63C) is
such that this atom points directly at the gallium center. On the
other hand H(23A), which was located in the final Fourier difference map, adopts a location that places the mid-point of the
C(23)-H(23A) bond near the quasi threefold axis of the gallium
atom, thus suggesting the presence of an agostic interaction.
Such interactions may, in fact, explain the isomerization of
[Ga(Ar),H] to 2. As shown in Scheme 1, an agostic interaction
between the gallium atom and a C - H bond of one of the orthotBu methyl groups (C-H,) could result in transfer of the H,
atom to the gallium atom and formation of a new Ga-C bond
in concert with the cleavage of a Ga-C(ipso) bond and 1.2
transfer of H, to the aryl ring.
A)
A),
A)
A),
considerably more complex than
X-ray structure analysis revealed that the colorless, crystalline product is, in
Fact. an isomer of the target compound (Fig. 2)."21
t Bu
t Bu
Scheme 1. Postulated rearrangement mechanism for the isomerization to give 2.
c1211
H123AI
It is germane to point out that Meller et al.1131have reported
that [Ga(Ar,)Cl] is converted to [Ga(CH,CMe,C,H,{ 3,5tBu,})(Ar)(Cl)] and a benzo[h]gallolane by heating in high vacuum at 140-160 "C. Presumably, the mechanism of this reaction
is different because we do not observe gallolane formation.
Moreover, the putative isomerization of [Ga(Ar,)H] to 2 takes
place under significantly milder conditions (ambient pressure
and a maximum temperature of 25 ' T ) .
Finally, attempts to prepare the analogous indium hydrides
have been unsuccessful so far. For example. reaction of the new
monomeric indium chloride [In(Ar),CI] (3) with LiGaH, in E t 2 0
at -78 'C results in 1 by aryl cleavage and transmetalation.
CI
c11041
Fig. 2. View of 2 showing the atom labeling scheme. All hydrogen atoms except
H(1). H(23A). and H(63C) are omitted forclarity. The I B groups
~
at C(4) and C(10)
are disordered. Important distances [A] and angles ['I: &(I)- C(1) 1.983(17),
&(I)
C(S2J 1.972(17), Ga(l) H(l) 1.43(10), C(W-C(X2) 1.551(23) G a ( l J . . .
H(23A) 2.28(2). G a ( l ) . . . H(63C) 2.03(2): C(l)-Ga(l)-C(82)120.2(6). C(l)-Ga(l)H(1) 131(5). C(82)-Ga(l)-H(I) 108(5). Ga(l)-C(82)-C(XO) 119.2(11). H(23AjGa(l)-H(63C) 168.4(7).
The hydride 2 is monomeric in the solid state and there are no
unusual intermolecular interactions. In this case it was possible
to detect the hydrogen atom attached to gallium in the final
Fourier difference map. Although the metric parameters are not
very accurate, it is clear that the environment of the gallium
atom is trigonal planar. There are no previous experimental val1254
t.'
VCH ~,.i.rluXsX~.rell.~L./IUfr
mhH. 0 - 6 9 4 5 f Weinburit, I994
Experimental Procedure
1: A solution of LiGaH, (8 mmol) in Et,O (20 mL) was added to a solution of
[Ga(Ar)CI,] [8] (0.39 g . l . 0 mmol) in Et,O (3 mL) at -78 C. The resulting reaction
mixture was allowed to warm slowly to 25 C and was stirred for a further 20 h at
this temperature. The solvent and volatiles were removed under reduced pressure
and the resulting white residue was extracted with hexane (10 mL). After 3 h this
stirred solution was filtered, and the volume of the filtrate reduced to 3 mL. X-ray
quality crystals of' 1 were grown by cooling the saturated solution to -20°C. The
yieldofl was73%(0.23g).(M.p. 134 C j Compound2waspreparedin42%yield
by a similar procedure. (M.p. 180 C. deconip.).
3: A slurry of InCl (I .I I 6.5.0 mmol) in hexane (50 mL) was added t o a suspension
of ArLi (2.52 g. 10 mmol) in hexane (200 mL). The reaction mixture was heated to
reflux for 18 h. The solvent and volatiles were removed under reduced pressure and
the resulting residue was washed with pentane (3 x 20 mL). The pentane extracts
were filtered through diatomaceous earth and the volume of the filtrate was reduced
OS70-OR33:94,.f712-1254 S fO.OO+ .2VO
Angeic. Ciietn.
Itil.
Ed. Engl. 1994, 33. N o . 17
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by 50%. Small colorlcss crystals of 3 formed in 18% yield (0.58 g) after storage of
this solution at -20 C for several days. (M.p. 170 C).
Received: January 20, 1994 [Z6636IE]
German version: Angew. Chem. 1994, iU6,1354
The Bonding Capability of Imido Complex
Fragments of Groups 5-7 with Regard to
the Isolobal Relationship**
Jorg Sundermeyer* and Diane Runge
Dedicated to Professor Helmut Werner
Inorgunic Chemistry. Orgunogulliurn Cofnpounfls,Purl 1,
Springer. Berlin. 1987.
on the occasion of his 60th birthday
[2] P. L . Baxter. A. J. Downs. M. J. Goode, D. W. H. Rankin, H. E. Robertson, J.
C'hi~nr.So(. C'hc.in Comn7uri. 1986. 805.
In bond theory organoimido and cyclopentadienyl ligands
[3] M. .I Goode. A. J Downs, C. R. Pulham. D. W. H. Rankin, H. E. Robertson.
show surprising parallels.[21If they are considered as anionic ligJ, Cheri~.Sol Chwr. Con~n~un.
1988, 768.
[4] P. L. Baxter. A. J. Downs. M . J. Goode. D. W. H. Rankin. H. E. Robertson, J
ands, they both make a maximum of six electrons available for
f'hcni SM. Dulton Truns. 1985. 807.
bonding with a metal cation.[31Both are 0.2 x-bonding ligand~,[~I
[5] C. R. Pulham. P. T. Brain. A. J. Downs, D. W. H. Rankin. H. E. Robertson. J.
which form 0 and K bonds with metal orbitals of the same symC h i ~ n iSoi..
.
CIi(~i7.Connirun. 1990, 177.
metry.I5] If the C,R; anion binds to a d"-M metal center (e.g.,
[6] M. T. Barlow. C . J. D a n . A. J. Downs. G. S. Laurensen, D. W. H. Rankin. J.
C ~ P ISfif..
~ I . D d i m Trans. 1982, 597.
do-W6+) and the dianion N R 2 to an isoelectronic d"-M' metal
[7] For interesting polycycles with gallium hydride moieties. see M. J. Henderson,
center
from the following group in the periodic table (e.g., doC. H. Kcnnard. C L Raston, G. Smith. J. C h ~ mSoc.
.
Chew. C~iminun.1990.
Re7+),two entities with the same electron count and comparable
1203: J . L. Atwood. S G. Bolt, C. Jones. C. L. Raston, Inorg. Cliem. 1991,3U.
valence orbitals result (e.g., [W(q5-C5R5)I5+or [Re(NR)]'+).
4868.
[XI R. Kiippe. M. Tdcke, H. Schnockel, Z. Anorg. Allg. Chern. 1991. 605, 3 5 : R.
Schrock et al.[61have already pointed out parallels in the chemKiippe. H. Schncickel, J Chew. Soc. Dalton Trans. 1993, 3393.
istry of complexes with the entity [M(NAr),] (M = Mo, W ;
[9] S. Schulz. S. Pusch, E. Pohl, S. Dielkus. R. Herbst-lrmer, A. Meller. H. W.
Ar = 2,6-iPr2C,H,) and those containing the metallocene unit
Roesky. Inorg. Chen. 1993, 32, 3343; M . A. Petrie, P. P. Power, H. V. Rasika
[Cp,M] ( M = Ti, Zr, Hf; C p = q5-C5H5).Gibson et al. extended
Dias. K. Ruhlandt-Senge. K . M. Waggoner. R. J. Wehmschulte. Organonietul/ic., 1993. 12. 10x6
this relationship to the linking fragments [CpM(NR)] ( M = Nb.
[in] I H N M R ( ~ O O . ~ ~ M H Z . C , D , . ~ ~ ~ K
I :,&T=M1 .S2 )9:( s , i x ~ . o - t ~ u ) , 1 . 3 5
Ta) and confirmed the isolobal character of these three complex
( s . H. /I-rBu). 6.41 (br. 2 H. GaH,), 7.40 ( 5 . 2 H. H-aryl). 2: fi = 1.46 (br. 2
fragments by quantum-mechanical calculations[71and reactivity
H. CH,). 1.70 (s. 6 H. 2 CH,), 6.62 (br. 1 H. GaH); 3.5-fBu,C,H3: 1.23 ( s . 18
studiesr8'(Scheme 1 , top). Recently we reported on M -M' coupH. i i i - / B u ) . 7.40 ( I , 1 H.p-H-aryl, J 1.8 H r J , 7 57 (d. 2 H, o-Hi-aryl,J 1.8 Hz).
Z.4.6-tBu,C,H2. 1 14(s.9H.p-rBu). 1.38(s. 18H,o-tBu).7.42(~.2H.H-aryI)
3: 0 = 1.31 (s.9 H.p-iBu). 1.58(s. 18 H,o-rBu).7.62(~.2H. H-aryl): l R ( K B r ) .
1 -t[cm
,
'1 = 2961 s. 2905 m, 2867 m. 2818 w sh. 1908 ni sh, 1887 s. 1584s. 1540
NR
R
in. 1530 w. 1476 m. 1461 m. 1392 s, 1361 s. 1255 ni, 1217 m. 1202 w. 1190 w,
I
II
I
1145 in. 1106 s br. 992 w sh. 965 m. 811 m. 767 m ; 2: i.[cniC'] = 2Y63 s, 2905
m. 2867 in. 1843 m. 1596 m, 1477 m, 1460 w, 1393 w. 1362 m, 1261 s. 1245 w
sh. 1202 u br, 1099 s; 1023 s. 899 w, 872 m, 802 s. 725 u sh, 714 m br; 3
i,[cm-'] = 2966 5 . 2901 m br. 2875 s. 1786 w, 1769 w. 1596 s. 1539 w. 1486 w
sh. 1462 s. I404 s. 1365 c. 1271 m sh, 1258 s. 1210 m. 1128 m. 1101 s. 1022 m
br. 9-70 w,906 in. 881 s, 811 s. 745 m. MS (CI. CH4): 1 : in;: 315 ( M I - H,
100"%J:HRMS: Calculated forC,,H,,h9Ga 315.1603; found315.1590.2: mlz
55Y (.I4'- H. 100%). 315 ( M + - rBu,C,H,. 47%): HRMS: Calculated for
C,,,HI,""Ga 559.3794:found 559.3778: 3: m i z 6 7 6 ( M - + CI), 605 (M'-CI).
395 (,I4 - - Ar): HRMS: Calculated for C,,,H,,InCI, (.MCI) 675.2954;
found 675.2945. The X-ray crystal structure of 3 has been determined and will
be published elsewhere.
Scheme 1. lsolohal relationships in imido complex fragments.
[I I ] C. Jones, G A. Koutsantonis, C. L. Raston. Pulxhrdron 1993. 12. 1829
[12] Crystalstructuredatafor 1.Cl,H,,Ga,monoclinic,spacegroupP2,~~~~.Z
= 2.
u = 9 9 ? 7 ( 1 ) . h=Y.694(2).c=10.273(1)A, /(=112.58(1), V=912.9(3)A3,
/ J ,",,~ , = l . l 5 g ~ n i ~ ~ . M o , , . i = 0 . 7 1 0 7 3 ~ , ~ i = 1 . 4 8 91711
m m uniquedata
~'.
ling reactions of the two homoleptic imidoyl cations
were collected at 173 K on a Nicolet P 3 diffractometer ( m scan technique.
[Re(NR),]+ and [Mo(NR),]" (R = tBu) with carbonyl meta4.0 < 21) < 50.0 1. Of these. 907 have I > 4 ~ 1 1 and
)
were used for structure
lates [Cp,M(CO),,J of Groups 6-8.19) It was shown that a
solution and refinement. R = 0.095. The oriho tBu groups are disordered. The
direct metal-metal interaction is possible between high- and
site occupation t:dctors for CX and C9 are 69(1)%: those for C14 and C15 are
55(1 J'% The hydrogen atoms on gallium could not be located and were not
low-valent metal centers. These results prompted us to the quesincluded in the refinement: the other hydrogen atoms were calculated in idealtion whether the bonding capability (concept according to R.
Crystal structure data for 2, C,,H,,Ga. monoired positions (C- H 0.96
Hoffmann[""]) of imido complex fragments [Cp,M'(NR),] (M
clinic. space group P Z , ; ~z, = 4. o = 9.355(2). h = 27.930(6). c = 14.110(3) A,
Groups 5, 6, or 7) can be determined along the route of
/ ~ = l ( l 7 . 1 4 ( 3 ) .1 ' = 3 5 2 3 . 0 ( 1 ) ~ ~ , p ~ ~ , ~ , = 1 . 0 5 9 g c m ~ ' , M o , , , i = 0 . 7 1 0 7 3from
~,
/I = 0 X O I mm- I. 4485 unique data were collected on a Siemens R 3m:V difselective M - M' coupling reactions. by binding representative
fractometer at 298K (20-0 scan technique. 3.5 > 211 < 45.0~).Of these. 1567
complex fragments with these entities to the classic 17 valence
had I > 4 u ( 1 ) and were used for structure solution and refinement.
electron unit [CpFe(CO),] . Extrapolation of these studies could
R = 0.0813. Two of the tBu groups are disordered. The site occupation factors
lead to the derivation of a new isolobal relationship between
are71(3)"/0 forC(41),C(42).andC(43): thoseforC(l01).C(104).andC(lOS)
are 47(2l'%. Further details of the crystal structure investigations may be obcarbonyl and imido complex fragments [Cp,M'(NR),,] .
tained from the Fachinformationszentrum Karlsruhe, D-76344 EggensteinAccording to the cyclopentadienyl-imido analogy, not only
Leopoldschafen ( F R G ) . on quoting of depository number CSD-58075.
the homoleptic imido complex fragments [Mo(NtBu),12 and
[13] A. Meller, S Pusch, E. Pohl, L. Himing. R. Herbst-Irmer, Chein. Ber. 1993.
i76.23S.
[*I Dr. J. Sundermeyer, DipLChem. D. Runge
Institut fur Anorganische Chemie der Universitlt
A m Hubland. D-97074 Wurzburg (FRG)
Telefax: Int. code (931)-888-4605
[**I High-valent derivatives ofthe d-metal acids. Part 11. This work was supported
by the Fonds der Chemischen Industrie and the Deutsche Forschungsgemeinschaft (SFB 347). We thank Professor Helmut Werner for his support and the
company H. C. Starck, Goslar. for a gift of high purity grade metal oxides and
chlorides. Part 10: Ref. [I].
[I 1
Gnrt,liii Hunrlhook of
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n . E d Dig/. 1994. 33, No. 12
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Verlugsge.cellsrhufimbH, 0-69451 Weinhrim, 1994
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057U-O833;94:121~-125S
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