Therefore, Clar's goblet has been a long-sought synthetic target for decades, motivating extensive advancements in synthetic chemistry , molecular structure and magnetism theory . The primary challenge in the chemical synthesis of Clar's goblet is to find a feasible way to construct its topologically frustrated sp 2 -C network with atomic precision, particularly the C-C bonds within the disjoint region. In addition, the high reactivity of radicals often leads to undesired decomposition. In 2020, Fasel and Feng's teams reported the on-surface synthesis of Clar's goblet and in situ investigation . The properties obtained by on-surface chemistry are unavoidably influenced by the interactions with the gold surface. Moreover, many key properties of Clar's goblet are difficult to explore under the stringent conditions (e.g., on a metal surface, under ultrahigh vacuum) of onsurface chemistry, and thus are still hidden. Overall, the precise synthesis of Clar's goblet by wet chemistry and revealing its unusual physical properties remain a long-standing and highly important challenge. In this Article, we report on the solution-phase synthesis of Clar's goblet and deciphering its intriguing physical properties, especially the spin-entanglement between the two confined electrons. The key C-C bonds in the disjoint region are constructed by an intermolecular radicalradical coupling approach. Moreover, introducing bulky substituents at the periphery of Clar's goblet enhances its kinetical inertness, making it easier to handle during isolation and investigation. Temperature-dependent magnetic studies reveal an antiferromagnetic (AFM) coupling between the two spatially segregated spins in Clar's goblet, with an average spin-spin distance of 8.7 Å and coupling strength of -0.29 kcal/mol. This unique spin spatial segregation is further demonstrated by theoretical and experimental studies of the radical cation state of Clar's goblet. This work experimentally demonstrated what has been long expected theoretically: the two individual spins in the hydrocarbon -Clar's goblet are entangled in the ground state.