To elucidate the structure-property relationships of luminescent metal-organic frameworks (MOFs) containing encapsulated metal halides (MH), we present a series of high-pressure diffraction and spectroscopic studies. These materials exhibit unique optical and electronic properties due to the isolated nature of MHs in MOF cavities. By investigating the effect of pressure on both structure and optical properties, we aim to discover new phenomena and potential applications in fields such as optoelectronics and energy conversion.