Domain: Organometallic synthesis

(4,6-dichloropyrimidine) and (3-iodophenol) were mixed in a reaction vessel. Then Cs2(CO)3 and anhydrous N,N'-dimethylformamide were added to it and the mixture was heated at 383 K for 12 h to yield compound M. M, Pd(PPh3)4 and CuI were loaded in another reaction vessel. Then, Et3N, tetrahydrofuran and trimethylsilylacetylene were injected to the mixture. After addition of all solvents, the mixture was stirred at room temperature for 12 h. When the reaction was completed, the major organic product was isolated and further reacted with tetrabutylammonium fluoride in tetrahydrofuran solvent to obtain N as the product. N was reacted with trans-PtI2(PEt3)2 and CuI using Et3N as base and toluene as solvent to get O as the major product. Please write the chemical formula of O.

Grading rubric:
criterion: Correctly identifies the first step as a double nucleophilic aromatic substitution (S_NAr) where both chlorides on the pyrimidine ring are replaced by 3-iodophenoxide groups.
weight: 10
criterion: Correctly identifies intermediate M as 4,6-bis(3-iodophenoxy)pyrimidine.
weight: 10
criterion: Correctly identifies the second stage as a Sonogashira cross-coupling reaction involving the aryl iodide sites and trimethylsilylacetylene.
weight: 10
criterion: Correctly identifies the role of tetrabutylammonium fluoride (TBAF) in the deprotection of the trimethylsilyl (TMS) groups to reveal terminal ethynyl groups.
weight: 10
criterion: Correctly determines the molecular formula of intermediate N as C_20H_12N_2O_2.
weight: 10
criterion: Correctly identifies the final step as a dehydrohalogenation/coupling reaction between terminal alkynes and the trans-PtI2(PEt3)2 precursor.
weight: 10
criterion: Correctly deduces that the major product O is a dinuclear complex containing two Pt(PEt3)2I end-caps linked to the organic backbone N.
weight: 10
criterion: Correctly calculates the total count of phosphorus atoms as P_4 based on the coordination of two PEt3 ligands per platinum center.
weight: 10
criterion: Correctly calculates the total carbon count as C_44 by summing the backbone (C_20) and the four triethylphosphine ethyl groups (4 × 6 = C_24).
weight: 10
criterion: Correctly provides the complete and final molecular formula as C_44H_70I_2N_2O_2P_4Pt_2.
weight: 10

Answer:
C44H70I2N2O2P4Pt2