Cyclobutadiene, C4H4, is unstable but can be stabilized in complexes such as (C4H4)Fe(CO)...

Cyclobutadiene, C4H4, is unstable but can be stabilized in complexes such as (C4H4)Fe(CO)3. In such complexes, C4H4 is planar and has equal C—C bond lengths:

(a)   After the formation of C—H and C—C rr-bonds in C4H4, what orbitals are available for 7r-bonding?

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(b)    Assuming Z)4h symmetry for C4H4, derive the symmetries of the four 7t-MOs. Derive equations for the normalized wavefunctions that describe these MOs, and sketch representations of the four orbitals.