The neutral gold cluster, Au3, has been trapped in a benzene matrix at 77 K and its e.s.r. spectrum observed: it consists of sixteen sets of quartets with a197(2)= 382.9 G (3.83 × 10–2 T), a197(1)= 58.0 G (5.8 × 10–3 T), and g= 1.865; these parameters suggest a slightly bent structure with 2B2(C2v) ground state.