Ferromagnetic superexchange in a 1D [LaIIIradical] coordination polymerElectronic supplementary information (ESI) available: SOMO and spin density distribution of the boaDTDA radical; additional magnetic data; structural and experimental details. CCDC 936895. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c3cc43267j

The first coordination polymer of a bridging radical 1,2,3,5-dithiadiazolyl ligand is reported. Upon coordination with the La(hfac) 3 fragment, the paramagnetic 4-(benzoxazol-2-yl)-1,2,3,5-dithiadiazolyl (boaDTDA) ligand forms a one-dimensional (1D) alternating [La(hfac) 3 boaDTDA] n polymer exhibiting ferromagnetic (FM) coupling between the radicals, mediated through the diamagnetic La III ion (hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato). The [La(hfac) 3 boaDTDA] n coordination polymer exhibits ferromagnetic (FM) coupling between the radicals, mediated through the diamagnetic La III ion. The lanthanum 6s orbital cannot be solely responsible for the superexchange mechanism.