_P.-Powell-auth.-Principles-of-Organometallic-Chemistry-Springer-Netherlands-1988

Problems
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Organomet. Chem., 300, 81.
Green, M. (1986) The road from alkynes to molybdenum~carbon multiple bonds. }.
Organomet. Chem., 300, 93.
Halpern, J. ( 1982) Formation ofC-H bonds by reductive elimination. Ace. Chem. Res., 15,
332.
Halpern, J. (1985) Activation ofC-H bonds by metal complexes. Inorg. Chim. Acta, 100,
41.
Heck, R.F. ( 19 79) Palladium catalysed reactions of organic halides with olefins. Ace. Chem.
Res., 12, 146.
Heck, R.F. (1985) Palladium Reagents in Organic Chemistry, Academic Press. London.
Herrmann, W.A. (1982) Methylene complexes. Adv. Organomet. Chem., 20. 160.
Negishi, E. ( 1982) Palladium and nickel catalysed cross coupling. Ace. Chem. Res., 15,
340.
Rosenblum, M. (1986) The chemistry of dicarbonylcyclopentadienyliron complexes. }.
Organomet. Chem., 300, 191.
Schrock, R.R. (1979) Alkylidene complexes of Nb and Ta. Ace. Chem. Res .. 12. 98.
Toscano, P.J. and Macilli, L.G. (1984) 8 11 and related organocobalt chemistry. Prag. Inorg.
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Vollhardt, K.P.C .. ( 1984) Cobalt-mediated cycloadditions. Angew. Chem. (lnt. Edn). 23.
539.
Problems
1. Discuss methods of preparation of transition metal compounds containing
metal-carbon a-bonds. Consider factors affecting their stability. Why is
[Ru(C 2 H 5 )(Cl)(PPh,),] stable only under a pressure of ethene?
(University of Leicester).
2. Treatment of MeMn(CO), with triphenylphosphine gives a product A of
molecular formula C 24 H 18 C\MnP. The 1 H n.m.r. spectrum shows signals due to
phenyl protons (relative intensity 15) and methyl protons (relative intensity 3 ).
The i.r. spectrum shows four bands in the region 2 O 58 to 1927 cm- 1 and
another at 162 3 cm- 1 • Propose, with reasoning. a structure for the product A.
(University of Leicester).
3. Two main mechanisms have been proposed for the carbonylation of
CH 3 Mn(CO),: the carbonyl insertion (A) and the methyl migration (B).
(a) Illustrate what is meant by these two possible mechanisms, A and B, using CO
as the carbonylating agent.
(b) Show that the use of 13 C-enriched CO cannot help to distinguish between
mechanisms A and B, although it can eliminate the possibility of direct insertion
from the gas phase.
(c) Decarbonylation of cis-CH,COMn(C0) 4 (1 'CO), which is formed by the carbonylation
reaction in (b ), gives a mixture of trans- and cis-CH,Mn(C0) 4 ( 13 CO) in
the ratio 1:2. Show that this result is consistent only with mechanism B.
( d) Explain in detail how the infrared absorption spectra of the reaction products
may be used for the preceding analysis.
(University of York).
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