The 1,3-Sn2O2-Heterocycle as a Ligand in Organometallic Compounds – Dimerization of the Inidene Species [{(CO)5M}2SnOR]– (M = Cr, W)
✍ Scribed by Peter Kircher; Gottfried Huttner; Katja Heinze; Laszlo Zsolnai
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 500 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Dimerized inidene complexes [(CO) 5 M …
Ϫ Sn(OR) … Ϫ M(CO) 5 ] 2 2system, which characterizes monomeric inidene species
still prevalent in the dimeric species 1. The (M = Cr, W; R = Et, iPr), 1, are obtained from [{(CO) 5 M} 2 SnCl 2 ] 2- by different routes. Dimerization occurs via alkoxy-donor tin-low-lying π*-type LUMOs of 1 are the rationale for the observed 119 Sn-NMR low-field shifts of 1. The dimeric acceptor bonding by which a planar Sn 2 O 2 ring is formed. The Sn-{M(CO) 5 } bonds are made in a plane vertical to this ring compounds 1 react with 2,4-pentanedione to form chelate compounds of the same type as those characteristically such that, with the R-O groups being almost coplanar with the Sn 2 O 2 ring, the overall geometry of the compounds shows obtained from monomeric inidene complexes: [{(CO) 5 Cr} 2 SnOEt] 2 2-(1a) reacts to give [{(CO) 5 Cr} 2 Sn(acac)] - idealized D 2h symmetry. -The 119 Sn-NMR resonances of 1 are found at rather low fields (M = Cr: δ ഠ 1400; M = W: δ ഠ 1170) (2). The experimental results are verified by X-ray analyses in addition to the usual spectroscopic and analytical indicating a low-lying tin-centered orbital in the LUMO range. Correspondingly EHT analyses show that the 3-center-4π investigations.