Domain: Supramolecular coordination chemistry

\(4,4'\text{-bipyridine}\) (Chemical formula: \(C_{10}H_{8}N_2\)) was refluxed with  \(1,3\text{-dibromopropane}\) (Chemical formula: \(C_3H_6Br_2\)) in \(N,N\text{-dimethylformamide}\) to yield compound \(A\). \(A\) was further stirred with large excess amount of \(\text{ammonium hexafluorophosphate}\) (Chemical formula: \(NH_4PF_6\) to afford ligand \(L\).In the next step, \(cis\text{-Pt(PEt}_3)_2\text{(OTf)}_2\) was treated with \(L\) in \(1 : 1\) molar ratio using \(\text{Acetone-d}_6\) as solvent to yield charges macrocycle \(M\). Could you please determine the \([M\text{-}2PF_6]^{2+}\) value?

Grading rubric:
criterion: Correctly explicitly identifies the ligand (Compound A) as a bis-quaternized 4,4'-bipyridinium derivative linked by a propyl chain.
weight: 10
criterion: Calculates the total formal charge of the bare macrocyclic core as +8 (derived from two +2 Pt centers and two +2 Ligands).
weight: 10
criterion: Interprets the mass spectrometry notation [M - 2PF6]2+ as the species formed by the association of the +8 core with exactly 6 hexafluorophosphate anions.
weight: 20
criterion: Distinguishes between the hexafluorophosphate (PF6) and triflate (OTf) species, explicitly rejecting the mass values associated with triflate.
weight: 20
criterion: Incorporates the mass contribution of exactly 6 PF6 anions in the calculation of the total ion mass.
weight: 20
criterion: Correctly extracts or calculates the m/z value for the [M - 2PF6]2+ species as approximately 1228 (accepting 1228.0 - 1228.2).
weight: 20

Answer:
m/z approximately 1228.1 for [M - 2PF6]^2+