Vidal, SaraIzquierdo, MartaKit Law, WaiJiang, KuiFilippone, SalvatorePerles Hernáez, JosefinaYan, HeMartín, Nazario2023-06-182023-06-1820161359-734510.1039/c6cc06072bhttps://hdl.handle.net/20.500.14352/23181Methanofullerenes such as the well-known [70]PCBM are commonly synthesized under harsh conditions to obtain the product as a mixture of site-isomers (namely a, b and minor c) due to the D5h symmetry of the C70 cage. We report the first site-selective synthesis of [70]methanofullerenes under light irradiation and low temperatures, thus avoiding time-consuming and highly expensive HPLC separations. Pure major site-isomers a-[70]PCBM and a-[70]DPM have been thus efficiently prepared including the crystal structure of 5b. Photovoltaic preliminary results revealed a slightly beneficial performance for a-pure [70]PCBM site-isomer devices.engjournal articlehttp://pubs.rsc.org/en/content/articlepdf/2016/cc/c6cc06072bopen access547crystal structureirradiationisomerlow temperaturesynthesisQuímica orgánica (Química)2306 Química Orgánica