Crystal Structure and Magnetic Modulation of Rubidium-Intercalated 2-Phenylnaphthalene

Intercalation of alkali metals into aromatic hydrocarbons offers significant potential for achieving organic magnetism. In this study, rubidium-intercalated 2-phenylnaphthalene molecular crystals were synthesized successfully by ultrasonic treatment and low-temperature annealing. Magnetic measurements demonstrate that the rubidium-intercalated samples exhibit typical Curie paramagnetism with a molar magnetic moment of approximately 0.44 μ_B. XRD and Raman spectroscopy measurements confirm that the structure and vibration information on the prepared samples differ from those of pristine 2-phenylnaphthalene, indicating that a new structure is formed by intercalating preparation. First-principles calculations yield optimized theoretical structures and magnetic moments that align with experimental observations, suggesting that Rb-5<i>s</i> electrons from intercalated rubidium are transferred to the C-2<i>p</i> orbitals of the organic molecules. Upon application of pressure, the intercalated crystal is predicted to transit from an antiferromagnetic to a nonmagnetic metallic state. These findings demonstrate that introducing rubidium atoms with strong reducing ability into aromatic hydrocarbons provides new opportunities for developing the magnetic properties of these materials.