Assignment of O–O and Mo=O Stretching Frequencies of Molybdenum/Tungsten Complexes Revisited

Table 12

Calculated Mo=O and O–O stretching frequencies in gas phase, with explicit solvation and with implicit solvation via PCM.

Level of theory	Solvent	/cm^−1	/cm^−1
M06L/def2-TZVP	No	976.99	967.87
	Acetonitrile, PCM^[a]	944.48	959.34
	Acetonitrile, explicit^[b]	952.75	961.73
	Water, PCM^[a],[c]	960.28^[d]
	Water, explicit^[b],[c]	959.20	968.15

^[a]Default implicit solvent of Gaussian 09 A.02 was used. ^[b]Three molecules of solvents were added. ^[c]Tight convergence criteria and ultrafine integration grid were used due to low imaginary frequency with default setting. ^[d]Mo=O stretch and O–O stretch are strongly coupled, and assignment is ambiguous and therefore not attempted.