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Nitrogen Dioxide and the Isoelectronic COOH Group as 5-Electron Donors in Carbonylmetal Complexes; Preparation and Characterization of the First УMetallacarboxylic AcidФ.

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Although further investigations must be carried out to confirm this mechanism[’], it should be pointed out that our
observation is most likely of fundamental importance for
an understanding of the catalytic decomposition of peroxides by transition metal complexes. Many complexes fulfill
the prerequisite that they can be reversibly oxidized and
have energetically low-lying excitation states which can
take up the decomposition energy of the peroxides. The
occurrence of a luminescence is not necessary. Under suitable conditions a reversal of this hydroperoxide decomposition, i. e. the photochemically catalyzed addition of water
to a ketone, could be achievedrsb1;this would constitute a
possible way of chemically storing light energy.
We have been able to establish by an X-ray structure
analysis that the two Re atoms in complex (2) are bridged
by a butadiene ligand in trans-configuration. The butadiene complex (2) is isomorphic with the analogous manganese complex[*’; it can only be formed by a symmetric
cleavage of COT. This could be of interest regarding the
formation of COT from acetylene.
The new compounds (4) and (5) were characterized by
elemental analyses, by their mass and IR spectral3],and by
X-ray structure analyses[41(Fig. 1).
Received: October 7, 1980 [Z 750 IE]
German version: Angew. Chem. 93,470 (1981)
[I] a) Review: D. Swern: Organic Peroxides, Vol. 1-111, Wiley-Interscience,
New York 1969, 1971 and 1972. h) A . C. Melnyk, N. K . Kildahl, A . R .
Rendina, D. H . Busch, J. Am. Chem. SOC. 101, 3232 (1979); H . Sigel, K .
Wyss, B. E. Fischer, B. Rib. Inorg. Chem. IS, 1354 (1979). and references
cited therein.
[2] Review: G. B. Schusfer. ACC.Chem. Res. 12, 366 (1979).
[31 J. C. Luong. L. Nadjo, M. S. Wrighron, J. Am. Chem. SOC. 100, 5790
141 a) F. E. Lyttle, D . M.Hercules, Photochem. Photobiol. 13, 123 (1971); H .
D. GaJney, A . W. Adamson. J. Chem. Educ. 52,480 (1975); h) A . Vogler,
L. El-Sayed, R . G.Jones. J. Namnarh, A . W. Adamson. Inorg. Chim. Acta
53, L35 (1981).
[5] The decomposition of (2). catalyzed by Mg- and Zn-porphyrins involving
a chemiluminescence, has already been reported: a) J. H . Helberger, D.
B. H e w . Ber. Dtsch. Chem. Ges. 72, 11 (1939); b) H . Linschitz in McElroy, Glass: Light and Life, John Hopkins Press, Baltimore 1961, p. 173.
[6] M. Wrighton. D. L . Morse, J. Am. Chem. SOC.96, 998 (1974).
[7] J:Y. Koo, G. B. Schuster. J. Am. Chem. SOC.99, 6107 (1977); 100,4496
181 [Ru(hpy)J’+ also chemiluminesces, albeit only weakly, in the catalyzed
decomposition of (2) in tetralin/dimethyl sulfoxide.
Nitrogen Dioxide and the Isoelectronic COOH
Group as 5-Electron Donors in Carbonylmetal
Complexes; Preparation and Characterization of
the First “Metallacarboxylic Acid”
By Barbara K . Balbach, Frantisek Helus, Franz Oberdorfe,
and Manfred L. Ziegler“’
Photolysis of Re,(CO),o (I) in the presence of NO and
cyclooctatriene (COT) leads, in accord with eq. (a), to formation of the products (2)-(8), of which the hydrido-complexes (6)-(8) have already been described[’]. The species
(4) and (5), as well as (6)-(8). are also formed on photolysis in the absence of COT [eq. (b)].
* Re21COlSC3H6
COT &Re2iCO18CL%
2% 151
Re3C0Je N 4
lo”/. 14 1
2% 131
5% (21
yRe~cO!p 101
I*] Prof.
Dr. M. L. Ziegler 1’1, DipLChem. B. K. Balbach, Dipl.-Chem. F.
Anorganisch-chemisches lnstitut der UniversitBt
Im Neuenheimer Feld 270, D-6900 Heidelberg (Germany)
Dr. F. Helus
Deutsches Krebsforschungszentrm
Im Neuenheimer Feld 280, D-6900 Heidelberg (Germany)
[ ‘1 Author to whom correspondence should he addressed.
0 Verlag Chemie GmbH, 6940 Weinheim, 1981
Fig. I. a) ORTEP diagram of (4) projected onto the NO,-Re(l)
plane. h)
ORTEP diagram of (5) projected on the COO-Re(1) plane. Bond lengths in
The data obtained are consistent with a trinuclear complex without Re-Re bonding. The coherence of the species (4) and (5) is secured by a central NO, or COOH unit,
both of which have 17 electrons; for the three Re atoms to
uphold the 18-electron rule, these ligands must function as
5-electron donors. (4) and (5) are diamagnetic.
The IR spectrum of (5) contains a sharp, intense band at
3700 cm-’, which we assign to an 0-H stretching vibration; the H-atom cannot be involved in bridging. It can be
replaced by deuterium by multiple dissolution of (5) in
[D4]methanol and stirring of the solutions. As expected,
the deuterated species shows a sharp band at 2700 cm-’.
Location of the H-atom in (5) is not possible by X-ray
structure analysis. On the basis of all these experimental
data, (5) is to be formulated as a metallacarboxylic acid in
which a carbonylmetal unit corresponds to the alkyl or aryl
moiety R in ROOH. Such a metallacarboxylic acid is then
stable, only if both oxygen atoms of the carboxyl group are
involved in coordination. The atoms of the central COOunit and the rhenium (Re(1)) bonded to the C-atom lie,
057&0833/81/0505-470 $ 02.50/0
Chem. Int. Ed. Engl. 20 (1981) No. 5
within the limits of accuracy, in one plane; the sum of the
internal angles at C and N is 360".
(4) has the same molecular geometry as (5), but the species are not isomorphic.
TeO,, SO, and Se0, could also be inserted into the molybdenum-carbon bond [eq. (a)].
A solution of (I) (1.3 g, 2 mmol) in tetrahydrofuran
(THF) (300 cm') is saturated with NO and cooled to
- 20 " C. After addition of 2 cm' of freshly distilled COT
the mixture is photolyzed for 3 h; the solution, which becomes deep-red on completion of reaction, warms to about
0°C. It was evaporated down to ca. 50 cm3, transferred
onto silica gel, and dried. The dried mass was treated with
n-hexane and the resulting suspensoid chromatographed
on a column (40 x 2.5 cm, 0.02-0.5 silica gel, n-hexane).
Six zones are formed: zone 1, COT (I); zone 2, (2); zone
3, (7); zone 4, (6); zone 5, (3); zone 6, (4)+ (5). Zones 4, 5,
and 6 were re-chromatographed (PSC plates, Merck, silica
gel F-254,2.5 mm, benzene), affording pure (6), (3) and (8).
(3) as a colorless solution. A further chromatographic separation had to be carried out for the separation of (4) and (5)
(Nucleosil 50-10, 300 x 0.4 cm, n-hexane, 0.05 bar, 3 cm3/
min, 28 " C ; detector 254 nm). Fractional crystallization
(room temperature to - 20 "C, cyclohexane/ether) afforded 40 mg of (4) (yield 5-6%, yellow needles) and 20
mg of (5) (yield 2%, yellow platelets); in each case the
yields are based on (I).
Received: July 14, 1980 [Z 751 a IE]
German version: Angew. Chem. 93,479 (1981)
[I] W.Fellmann, H . D. Kaesr, Inorg. Nucl. Chem. Lett. 2, 63 (1966); D. K.
Huggins, W. Fellmann, J. M . Smith, H . D. Kaesr, J. Am. Chem. Sac. 86,
4841 (1964); R. Saillant, G.Barcelo, H . D. Kaesz, ibid. 92, 5739 (1970).
121 H. E. Susse, M.L. Ziegfer, 2. Anorg. Allg. Chem. 392, 167 (1972).
131 (4): IR (vco; cyclohexane) 2083 m, 2040 vs, 2003 s, 1992 ms, 1980 m, 1965
ms, 1955 m. MS: Re,(CO),,NO?obs. 996.775, calc. 996.787. (5): IR (vco;
CHCI,) 2080 m, 2040 vs, 2003 s, 1990 ms, 1957 ms; (voH and voD; CHCI,)
3700 s and 2700 s; 1595 m. MS: Rea(CO),.,COOHa obs. 995.799, calc.
141 (4): monoclinic, space group F?,/a with a= 1397.1(7), b= 1754.8(7),
c=923.0(5) pm, 8=95.87(5)", Z=4.4265 independent reflections other
than zero, Siemens AED, 5-value method, MoKn radiation,
4.436~2k67.461). R=0.087. (5): monoclinic, space group P2,/n with
a=683.4(1), b= 1776.3(4), c= 1844.4(4) pm, 8=99.33(1), Z=4. 3995 independent reflections other than zero (P3/DATA GENERAL NOVA 3, Qscan, MoKar0<2 k60.0). R=0.049. Reflections for 1<2.50(l) were not
taken into consideration in the case of (4) and (5).
(r), E = S ; ( 3 ) , E = S e ;
(1 )
By Winfried Dell and Manfred L. Ziegler"]
The insertion of SO, and SeO, into metal-carbon a-bonds
is already well documented1']. The insertion of TeO, was
considered as unrealizable, since the activation of a TeO,
molecule appeared possible only under conditions in
which the alkyl or aryl educt and/or the insertion product
would no longer be stable. We have now succeeded in activating TeO, by evaporation of TeO, in a metal evaporator
and condensation in an ether matrix at - 196°C. The complex q7-C7H,Mo(C0)2CH3(I)['], previously prepared by
us, provided a species containing an extremely reactive
molybdenum-methyl carbon bond suitable for an electrophilic EO, insertion (Table l)[']. As expected, aside from
[*I Prof. Dr. M. L. Ziegler, DipLChem. W. Dell
Anorganisch-chemisches Institut der Universitst
Im Neuenheimer Feld 270, D-6900 Heidelberg (Germany)
Chem. Inr. Ed. Engl. 20 (1981) No. 5
= Te
Analogously to the synthesis of (I) we were able to prepare the phenyl derivative (5) from q7-C7H7Mo(CO)2Br
and LiC6H5[']. However, the Mo-Cphenyl bond proved to
be less reactive than the Mo-Cmethy, bond in (I): with (5).
only the insertion of SO, could be achieved [eq. (b)].
The species (1)-(6) were characterized by elemental
analysis, by their IR and 'H-NMR spectra and, in part, by
mass spectra. The monomolecular composition of the compounds (2)-(4) followed from molecular weight determinations on (2) (obs. 327 (322), osmometrically, dichloroethane) and comparison of the 'H-NMR and IR spectra of
(21, (3), (4), and (6). The phenyl derivative (6) had already
been prepared by us by reaction of q7-C7H7Mo(CO),I with
AgS02C,H,[41.A characterization of the complexes (1)-(6)
by X-ray structure analysis was not possible owing to their
thermal instability; (2) can be stored for a few hours at
room temperature; ( I ) , (3), and (4) can be kept for only a
few minutes.
In the 'H-NMR spectrum (Table 1) of (I), the signal for
the methyl protons appears at 6= - 0.25, owing to the high
electron density on the methyl carbon atom; thus (I) is exactly predestined for such an insertion according to concepts on the mechanism of EO, insertion[']. As expected
the signals for the CH3 protons in the E0,-insertion products (2)-(4) appear at low field; the vco bands of the species (2)-(4) and (6) are shifted to higher wave numbers
compared to those of the methyl-(I) and of the phenyl
compound (5).
Table 1. Some spectroscopic data of compounds (1)-(6)
IR [cm-'I
Preparation of q7-C7H7Mo(C0)2E02CH3
(E = S,
Se, Te); the First Insertion of TE02 into a MetalCarbon Bond
(41, E
(CHAX, vs)
Nujol, KBr window
'H-NMR (&values, TMS)
G H - , CHI
(s, 7 H) (s, 3 H)
1975, 1930
2020, 1975
2MM, 1940
1990, 1930
1985, 1935
2030, 1990
1150, 1035.
1070, 887
960, 785,
750, 695
1155, 1085,
1025, 1015,
6.88 (m. 3 H)
7.40 (m. 2H)
7.47 (m, 3H)
1.72 (m, 2 H )
SeO, (500 mg, 4.5 mmol) was evaporated in a metal
evaporatorL4]at - 196 "C within 2 h (20 A, 220 V) onto an
ether matrix (50 cm'), heated to -78"C, and then treated
with a solution of (I) (100 mg, 0.4 mmol) in tetrahydrofuran pre-cooled to -78°C. The reaction solution was al-
0 Verlag Chemie GmbH. 6940 Weinheim, 1981
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acid, group, electro, уmetallacarboxylic, complexes, preparation, carbonylmetal, dioxide, isoelectronic, first, cooh, nitrogen, donor, characterization
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