Determine the structure of $\mathrm{Mn_2O_7}$

$\mathrm{Mn_2O_7}$ is the anhydride of permanganic acid and has a structure analogous to $\mathrm{Cl_2O_7}$.

Its structure can be written as: $\mathrm{O_3Mn-O-MnO_3}$

So, the molecule contains:

• two terminal $\mathrm{MnO_3}$ groups,
• one bridging oxygen atom forming $\mathrm{Mn-O-Mn}$.

Check the coordination around Mn

Each Mn is bonded to:

• three terminal oxygen atoms,
• one bridging oxygen atom.

Thus, each Mn has four oxygen atoms around it.

Therefore, Mn is tetrahedrally surrounded by oxygen atoms, not octahedrally.

So:

• (A) True
• (B) False

Check for bridge

Since the structure is $\mathrm{O_3Mn-O-MnO_3}$, there is clearly a $\mathrm{Mn-O-Mn}$ bridge.

So:

• (C) True

Check for Mn–Mn bond

The two Mn atoms are connected through an oxygen bridge, not directly.

Hence there is no $\mathrm{Mn-Mn}$ bond.

So:

• (D) False

Evaluate the options

Correct statements are A and C only.

Therefore, the correct option is: $\boxed{\text{A}}$

Comparison with stored answer

Stored correct answer: A

Our derived answer matches the stored answer.