. Author manuscript; available in PMC: 2009 Dec 3.

Published in final edited form as: J Am Chem Soc. 2008 Jun 7;130(26):8122–8123. doi: 10.1021/ja800265s

Table 1.

Vibrational frequencies (cm⁻¹) of Fe/O₂ species, the corresponding calculated ¹⁸O EIEs, and experimental ¹⁸O E/KIEs.

molecule	Frequency (cm⁻¹)			¹⁸O EIE (calc)^a	¹⁸O EIE (expt)^b	¹⁸O KIE (expt)^c
molecule	mode	ν_16-16	ν_18-16	¹⁸O EIE (calc)^a	¹⁸O EIE (expt)^b	¹⁸O KIE (expt)^c
Fe^III-OO^•−	Fe-O^d	555	526	1.0080	1.0054 (Mb)	ND^e
	O-O^d	1136	1100^f

Fe^III-OOH	Fe-O^g	621	599	1.0172	1.0113 (Hr)	1.0120 (HppE)
	O-O^g	844	820^f
	O-H^h	3539	3527
	O-O-H^h	1205	1199

Fe^III-OO^tBu	Fe-Oⁱ	637	612	1.0187	ND	ND
	O-O^j	860	829^f
	O-^tBu^j	746	738

	Fe-O^k	547	524	1.0143	ND	1.0102 (TauD)
	O-O^k	884	863^f
	O-C^k	965	946
	O-C-O^k	728	710

Fe^IV=O	Fe-O^l	821	787	1.0287	ND	1.0215 (ACCO)

The ¹⁸O EIEs were calculated using the Bigeleisen-Mayer equation and known frequencies (Ref ⁸).

Measured ¹⁸O EIEs for O₂-binding proteins myoglobin (Mb) and hemerythrin (Hr) (Ref ¹⁴).

This work.

Not determined.

ν_18-16 was calculated as follows: ν_18-16 = (ν_16-16 ν _18-18)^½ (Ref ⁸).

Ref ¹.

ⁱ

Ref ⁷.