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

Problems
relation to each other. Discussion of this area is outside the scape of this book;
some relevant literature is cited.
11.7 References
Adams, R.D. and Horvath, I.T. (1985) Novel reactions of metal carbonyl cluster
compounds. Prag. Inorg. Chem., 33, 127.
Bradley, J.S. (1983) Carbido carbonyl metal complexes. Adv. Organomet. Chem., 22, l.
Chini, P. (1980) Large metal carbonyl clusters. ]. Organomet. Chem., 200, 37.
Grimes, R.N. (1983) Metals in borane clusters. Ace. Chem. Res .. 16, 22.
Hali, K.P. and Mingos, D.M.P. (1984) Cluster compounds of gold. Prog. Inorg. Chem .. 32,
237.
Johnson, B.F.G. (Ed.) (1980) Transition Metal Clusters, Wiley, Chichester.
Lewis, J. and Johnson, B.F.G. (1981) Carbonyl clusters. Adv. Inorg. Chem. Radiochem., 24,
225.
Mingos, D.M.P. (1984) The polyhedral electron pair approach. Ace. Chem. Res .. 17, 311.
Mingos, D.M.P. (1986) Bonding in molecular clusters and their relationship to bulk
metals. Chem. Soc. Revs., 15, 31.
Muetterties, E.L. (1982) Metal clusters: bridges between molecular and solid-state
chemistry. Chem. & Eng. News, Aug. 30, p. 28.
Wade, K. (1976) Structural and bonding patterns in cluster chemistry. Adv. Inorg. Chem.
Radiochem., 18, l.
Problems
1. Give an account ofthe basis and use ofthe skeletal electron counting rules for
clusters.
Derive the polyhedral electron count for each of the following species and use
this number to predict the structure of the molecule or ion.
(a) B,H 11 (b) C,B,H, (c) B, 0 H 10 AsSb (d) (Ph,P),PtC,B 9 H 11
(e) [SnC 5 Me 5 ]+ (f) Co,(C0) 9 SnMe (g) B 9 H 15 (h) Fe 5 (C0), 5 C
(i) [Pb,] 2 - (j) B, 0 H 11 PC (k) Me 2 C 2 C0 4 (C0), 0 (l) C 6 H 6 Cr(CO),.
2. Show how the molecular structures of the following pairs are related:
(a) B 6 H~-
and Ru 6 (CO)~;
(b) B 5 H 9 and Fe(B 4 H 8 )(CO),
(c) B 4 H 10 and (Ph,P) 2 Cu(B,H 8 )
Derive the p.e.c. for each cluster and discuss the isolobal relationships between
the groups which are interchanged in the clusters.
3. Discuss the isolobal relationship between CO and Os(CO), groups in the
context of the structures of Rh 6 (C0), 6 and of [Os, 0 (C0) 24 C]>-. Show how the
p.e.c. for the latter is consistent with the replacement of the triply bridging CO
groups in an octahedral cluster [Os 6 (C0), 6 C]>- by Os(CO), groups.
4. Show how the electron counting rules can be extended to account for the
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