Here we discuss the reaction products of laser ablated alkali chlorides and elemental chlorine. Salt ablation using this technique combined with matrix-isolation spectroscopy allows for the formation and characterization of novel anionic species. The laser ablation of solid MCl with M = Cs, Rb, and K in the presence of Cl2 produced free [Cl3]- ions which were isolated in solid noble-gas matrices. For M = Cs, Rb, K, and Na, the ion pairs M+[Cl3]- are the main reaction products. Trends in the formation and bonding of these trichloride anions will be discussed. In contrast to the trifluoride analogues, the isolated ion pairs M+[Cl3]- feature a systematic distortion due to metal coordination.