Table 1.

g-Tensor principal values of quinone related radicals in RCs of Rb. sphaeroides and of model systems in nonprotic organic solvent

g value (±0.0001)	Rb. sphaeroidesa			Model systems
	${\text{UQ}}_{\text{B}}^{•-}$(pH 7.0)	${\text{RQ}}_{\text{B}}^{•-}$(pH 9.5)	${\text{RQ}}_{\text{B}}^{•-}$(pH 4.5)	UQ•−b	RQ•−c
gx	2.0062	2.0057	2.0055	2.0070	2.0058
gy	2.0053	2.0048	2.0045	2.0054	2.0049
gz	2.0021	–	–	2.0020	2.0017

^–Values could not be measured accurately due to the overlapping with a small fraction of D^•+ (see Fig. 3b, c)

^aValues obtained in this work using quintuple mutant RCs, in which the high-spin Fe²⁺ was replaced by diamagnetic Zn²⁺

^bValues corresponding to ubiquinone-3 (UQ-3) as taken from Ref. [19]

^cValues obtained in this work using rhodoquinone-3 (RQ-3)