Characterization and structures of intermediates in the reactivity of CpWOs 3(CO) 11( μ3-CTol) towards dihydrogen and water
Initial decarbonylation of CpWos 3(Co) 11( μ 3-CTol) (1: Cp = η 5-C 5 H 5, Tol = p-C 6H 4Mc) with the Me 3NO/MeCN followed by reaction with dihydrogen and water produces a dihydrido comlex CpWOs 3( CO) 10( μ 3-CTol)( μ-H) 2 (2), a ‘butterfly’ cluster with a 60 valence electron (VE), and an oxo comle...
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Published in | Journal of organometallic chemistry Vol. 526; no. 2; pp. 215 - 225 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
1996
|
Subjects | |
Online Access | Get full text |
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Summary: | Initial decarbonylation of CpWos
3(Co)
11(
μ
3-CTol) (1: Cp =
η
5-C
5
H
5, Tol =
p-C
6H
4Mc) with the Me
3NO/MeCN followed by reaction with dihydrogen and water produces a dihydrido comlex CpWOs
3(
CO)
10(
μ
3-CTol)(
μ-H)
2 (2), a ‘butterfly’ cluster with a 60 valence electron (VE), and an oxo comlex CpWOs
3(CO)
10(
μ-O)(
μ
3-CTol) (4) respectively. Complex 2 reacts either with carbon monoxide to produce the starting alkylidyne complex 1 by reductive elimination of dihydrogen or with PPh
3 to afford a 62 VE ‘butterfly’ complex. CpWOs
3(CO)
10(PPh
3)(
μ
3-CTol)(
μ-H)
2 (6). Thermolysis of 2 in the presence of water gives a hydrido oxo alkylidene complex,
syn-CpWOs
3(CO)
9(
μ-O)(
μ-CHTol)(
μ-H) (3a), in which the totyl substituent on the alkylidene carbon is oriented
syn to the μ-oxo ligand. Thermolysis of 4 at 110°C induces decarbonylation to give a tetrahedral alkylidyne complex CpWOs
3(CO)
9(
μ-O)(
μ
3-CTol) (5), which is reversibly converted back to 4 upon exposure to carbon monoxide. Complex 5 reacts with dihydrogen to afford a mixture of two isomeric hydrido oxo alkylidene complexes, antiCpWOs
3(CO)
9(
μ-O)(
μ-CHToL)(
μ-H) (3
b,
c). The
syn-isomer 3a is also produced from a mixture of 3b and 3c by thermolysis in boiling toluene. Compounds 2, 3a,b,c, 4, 5, and 6 haven been isolated as crystalline solids and characterized by spectroscopic (IR, MS,
1H and
13CMMR) and analytical data. The structures of 2 and 6 have been determined by single crystal X-ray diffraction studies. Compound 2 crystallizes in the orthorhombic space group
P2
12
12
1 with unit cell parameters
a = 14.18(1),
b = 28.46(1),
c = 13.59(3)
A
̊
,
V = 5484(13)
A
̊
3
and
Z = 8. Compound 6 crystallizes in the monoclinic space group
P2
1/
n with unit cell parameters
a = 19.298(2),
b = 22.406(4), c = 9.364(1)
A
̊
, β = 92.83(9)°, V = 4044.0(9)
A
̊
3
and
Z = 4. Diffraction data were collected on a CAD4 diffractometer, and structures were refined to
R = 0.0957 and 0.0510 for 2 and 6 respectively. Both 2 and 6 are based upon a ‘butterfly’ WOs
3 metal core with a respective dihedral angle of 114.3(2)° and 113.6(4)° between the WOs(2)Os(1) and WOs(2)Os(3) planes. Each molecule consists of three Os(CO)
3 units and a CpW(CO) fragment, except that the Os(1) center in 6 is additionally coordinated with PPh
3. The
μ
3-alkylidyne caps unsymmetrically the respective WOs(2)Os(3) face of both complexes. |
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ISSN: | 0022-328X 1872-8561 |
DOI: | 10.1016/S0022-328X(96)06562-X |