A modular synthetic route has been developed to prepare a new series of cationic ruthenium(II) complexes with electron-withdrawing 1,2-diacylcyclopentadienyl ligands. The 2-acyl-6-hydroxyfulvenes were synthesized from cyclopentadienide and acyl chlorides and converted to Tl(I) cyclopentadienyl salts using Tl 2 SO 4 /KOH. Transmetalation with [Ru(η 6 -p-cymene)(μ-Cl)Cl] 2 followed by PF 6 − metathesis gives the complexes [Ru{η 5 -1,2-C 5 H 3 (CO–R) 2 }(η 6 -p-cymene)][PF 6 ] (R = t-Bu, p-Tol, p-ClC 6 H 4 , p-IC 6 H 4 ) in moderate to high yields. The new compounds were characterized by NMR and IR spectroscopy; mass spectrometry and elemental analysis were performed where applicable. X-ray analysis of one of the complexes confirms that electron-deficient Cp ligands retain η 5 -coordination and structural planarity within Ru(II)–arene sandwich architectures, highlighting their potential utility in electronically tunable organometallic frameworks.