problem 1: Strained alkenes like cyclopropene or norbornene bind unusually strongly to metals. Recommend a reason why.
problem 2: Alkynes readily bridge M-M bonds, in which case they act as 2e donors to each metal. Sketch the product of the reaction below, pointing out the hybridization of the C atoms.
PhCCPh + Co_{2}(CO)_{8 }→ (µ_{2}-PhCCPh)Co_{2}(CO)_{6} + 2CO
problem 3: Draw as many bonding modes for cyclooctatetraene as you can think of.
problem 4: Sketch the three π-MOs of the allyl anion, [C_{3}H_{5}]^{–}. Draw metal d-orbitals which can interact with these MOs and name the type of bonding (e.g. M→L π-acceptor).
problem 5: The M-P distance in (η^{5}-C_{5}H_{5})Co(PEt_{3})_{2} is 221.8 pm and the P-C distance is 184.6 pm. The corresponding distances in [(η^{5}-C_{5}H_{5})Co(PEt_{3})_{2}]+ are 223 pm and 182.9 pm. Account for the changes in such distances as the former complex is oxidized.
problem 6: Predict the product of the reactions between:
a) [Ru(η^{5}-C_{7}H_{9})(η^{6}-C_{7}H8)]^{+} and H^{–}
b) [W(η^{5}-C_{5}H_{5})_{2}(η^{3}-C_{3}H_{5})]^{+} and H^{–}.
problem 7: Ligands of type X–Y only give 3c-2e “agostic” bonds to transition metals if X = H and Y lacks lone pairs. Why do you think this is so (consider alternative structures if X and Y are not H)?
problem 8: [IrH_{2}(H_{2}O)_{2}(PPh_{3})_{2}]^{+ }reacts with indene to give [Ir(C_{9}H_{10})(PPh_{3})_{2}]^{+}
A) On heating, this species rearranges with H_{2} loss to provide [IrH(C_{9}H_{7})(PPh_{3})_{2}]^{+}
B) Only A reacts with ligands like CO to displace C_{9}H_{7}. What do you think are the structures of A and B?