The synthesis of triethylphosphine gold(I) 4-nitrobenzenethiolate and solvent dependent visible absorption spectra of 4-nitrobenzenethiolate

Abstract

Abstract The synthesis of triethylphosphine gold(I) 4-nitrobenzenethiolate, Et 3 PAu(SC 6 H 4 NO 2 -4), is reported. Et 3 PAu(SC 6 H 4 NO 2 -4) displays a low energy visible electronic absorption band which is solvent dependent: EtOH ( λ max = 385 nm), acetonitrile ( λ max = 391 nm), THF ( λ max = 395 nm), and DMSO ( λ max = 402 nm). The corresponding low energy visible electronic absorption band of 4-nitrobenzenethiolate, 4-NO 2 C 6 H 4 S − also shows solvent dependency: acetonitrile, ( λ max = 484 nm), DMSO ( λ max = 502 nm), dimethylformamide ( λ max = 505 nm). The positive solvatochromic shifts for Et 3 PAu(SC 6 H 4 NO 2 -4) and 4-NO 2 C 6 H 4 S − are consistent with an intraligand (IL) charge transfer transition, i.e. π(S) → ∗π (C 6 H 4 NO 2 -4) or n(S) → ∗π (C 6 H 4 NO 2 -4). Assignment of 4-NO 2 C 6 H 4 S − was aided by a DFT calculation.