Table 1.

Selected structural parameters of SS2^NHC and 2^TPP

	SS-2NHC	2TPP
AuI⋅⋅⋅AuI (Å)	2.8667(10)–3.3141(15)	2.85528(18)–3.21332(19)
Ccentre–AuI (Å)	2.03(2)–2.075(8)	2.064(3)–2.082(3)
CNHC–AuI (Å)	2.03(2)–2.08(4)	/
P–AuI (Å)	/	2.2546(8)–2.2735(8)
τ	0.32	0.68

Bond distances (Å) of Au^I⋅⋅⋅Au^I, C_centre–Au^I, C_NHC–Au^I and P–Au^I, and geometry index τ values. The statistical significance of the errors for the bond distances is derived from the precision of the SCXRD data (Suppl. Table 1).