The reaction of 2,5-diphenylphosphacymantrene with solid KOH in the presence of crown ethers: Synthesis of the anionic η4-phosphoryl manganese complexes

2,5-Diphenylphosphacymantrene (1) reacts with solid KOH in the presence of crown ethers in C6H6 or CH2Cl2 at room temperature adding OH nucleophile to the phosphorus atom to afford anionic complexes [(CO)3Mn-η4-2,5-Ph2H2C4P(double bond; length as m-dashO)H]− [K−Crown]+, where Crown = 18-crown-6 (2) or dicyclohexyl-18-crown-6 (3). Complexes 2 and 3 are characterized by 1H, 31P, 13C NMR and IR-spectra. The structure of 2 is established by X-ray crystal structure data.