The UV-VIS spectrum of a CH₂Cl₂ solution of the gold (I) compound shown below with R = Ph is: λ_max (ε) = 239 (92500), 269 (67 000), 286 (72 000), 303 (28 000), 315 nm (21000 dm³ mol⁻¹ cm⁻¹).

(a) π* ← π transitions contribute to the observed spectrum. How do these arise? 

(b) Is the compound coloured? 

(c) You are asked to compare the UV-VIS spectra of a series of these compounds with different R substituents. Why should you compare plots of ε against λ rather than A against λ?

Transcribed Image Text:

R3PAu N AuPR3