. Author manuscript; available in PMC: 2010 Sep 7.

Published in final edited form as: Inorg Chem. 2009 Sep 7;48(17):8325–8336. doi: 10.1021/ic900961k

Table 3.

Physical properties of 2•O₂X and 3•O₂X complexes.

Complex	Solvent	λ_max (nm)	μ_O-O (cm⁻¹)	μ_Fe-O (cm⁻¹)	J (cm⁻¹)	δ (mm/s)	ΔE_Q (mm/s)	η^f	Fe⋯Fe (Å)
		[ε] (M⁻¹ cm⁻¹)	[¹⁸O₂]	[¹⁸O₂]
2•O₂AsMe₂	MeCN	348, 632	845a	464^a					3.27
		[7300, 2100]	[796]	[443]
2•O₂PPh₂	CH₂Cl₂	368, 678	845, 853	465, 475	57 ± 7	0.56(1)	−1.26(2)	0.4
		[6000, 2100]	[829]^b[807]	[455]
2•O₂PPh₂	MeCN	358, 686	845, 853	465, 476	57 ± 7	0.56(1)	−1.26(2)	0.4	3.25
		[7400, 2200]	[807]	[455]
2•O₂CPh	CH₂Cl₂	not observed
3•O₂AsMe₂	MeCN	not observed
3•O₂PPh2^c	CH₂Cl₂	344, 509, 621	898		60 ± 10	0.56(2)	0.86(5)	~0
		[7200, 1600, 1800]	[845]			0.54(2)	−0.52(3)	~0
3•O₂PPh₂^d	MeCN	338, 509, 590	897	477	60 ± 10	0.53(2)	−1.03(4)	~1	3.47
		[8300, 2000, 2300]	[848]	[458]
3•O₂CPh ^e	CH₂Cl₂	588	900	476
		[1500]	[850]	[460]

Measured in CH₂Cl₂.

μ_0-O from ¹⁶O¹⁸O.

Resonance Raan spectroscopy indicates incomplete conversion; some 2•O₂PPh₂ remains, probably red-shifting the peroxo-to-metal charge transfer to 621 nm. In addition, an unknown amount of 3•O₂PPh₂ has decayed to 4•O₂PPh₂, reducing the measured extinction coefficients.

Mössbauer values represent 80% of the total iron.

Values from reference ⁴⁰.

η= (V_xx − V_yy)/V_zz is the asymmetry parameter of the electric field gradient tensor.