doi:10.1039/d5tc03820kengLiu, XiaomingArauzo, AnaFuertes, SaraGiner Planas, JoséBartolomé, ElenaPure and mixed {Nd/Yb} carborane-based metal–organic frameworks integrating slow magnetic relaxation, magnetocaloric effect and NIR emissionART-2026-149142Multi-lanthanide metal–organic frameworks (MOFs) offer a flexible route for designing multifunctional materials. Here we report a carborane-based isostructural series of MOFs of formula {[(NdyYb1−y)3(mCB-L)4(NO3)(DMF)x]n·Solv}, including the homometallic Nd (y = 1) and Yb (y = 0) compounds and a mixed Nd/Yb analogue (y = 0.44). Magnetic, magnetocaloric and near-infrared (NIR) optical properties were investigated by dc/ac magnetometry, X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD), and photoluminescence. Nd3+ and Yb3+ yield MOFs combining slow relaxation of the magnetization (U/kB ∼ 19 K), cryogenic magnetocaloric response (−ΔSm ∼ 1.6 R at 5 T, 1.8 K) and ion-centered NIR luminescence. Notably, the mixed Nd/Yb MOF further extends this multifunctionality by exhibiting dual NIR emission at 998 nm and 1060 nm arising from partial Nd → Yb energy transfer. These results underscore carborane ligands as effective blocks for engineering multi-lanthanide frameworks, and highlight {Nd/Yb} MOFs as multifunctional materials for quantum technologies, optical communication, and cryogenic cooling.2026http://zaguan.unizar.es/record/17105310.1039/d5tc03820khttp://zaguan.unizar.es/record/171053oai:zaguan.unizar.es:171053info:eu-repo/grantAgreement/ES/AEI/CEX2023-001263-Sinfo:eu-repo/grantAgreement/ES/DGA/E12-23Rinfo:eu-repo/grantAgreement/ES/DGA/E17-23Rinfo:eu-repo/grantAgreement/ES/MICINN/PID2022-136892NB-I00info:eu-repo/grantAgreement/ES/MICINN/PID2022-138492NB-I00info:eu-repo/grantAgreement/ES/MICIU/PID2021-122869NB-I00Journal of materials chemistry. C (2026), [14 pp.]by-nchttps://creativecommons.org/licenses/by-nc/4.0/deed.esinfo:eu-repo/semantics/openAccess