title: New NIR-emissive tetranuclear Er(III) complexes with 4-hydroxo-2,1,3-benzothiadiazolate and dibenzoylmethanide ligands: synthesis and characterization.
abstract: New tetranuclear heteroleptic complexes [Er4(dbm)6(O-btd)4(OH)2] (1) and [Er4(dbm)4(O-btd)6(OH)2] (2) (O-btd = 4-hydroxo-2,1,3-benzothiadiazolate and dbm = dibenzoylmethanide) and their solvates with toluene, THF and CH2Cl2 were prepared using two synthetic approaches. The structures of the products were confirmed by single-crystal X-ray diffraction. Magnetic properties of 1 and 2 are in good agreement with X-ray data. The effective magnetic moment (μeff) values at 300 K for 1 and 2 corresponds to a system of 4 non-interacting Er(III) ions in the ground state 4J15/2 with g = 6/5. At ambient temperature and upon excitation with λexc = 450 nm, complexes 1 and 2 exhibit luminescence at 1530 nm, i.e. in the near infra-red (NIR) region. The luminescence intensity grows with increasing the number of the (O-btd)− ligands in the complexes. This observation suggests (O-btd)− as a new efficient antenna ligand for the lanthanide-based NIR luminescence.
authors.affiliation: Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk, Russia. konch@niic.nsc.ru.
authors.forename: Taisiya S
authors.initials: TS
authors.lastname: Sukhikh
authors.forename: Denis A
authors.initials: DA
authors.lastname: Bashirov
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Kuratieva
authors.forename: Anton I
authors.initials: AI
authors.lastname: Smolentsev
authors.forename: Artem S
authors.initials: AS
authors.lastname: Bogomyakov
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Burilov
authors.forename: Asia R
authors.initials: AR
authors.lastname: Mustafina
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Zibarev
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Konchenko
mesh_terms: D047188:Chalcones / Q000138:chemical synthesis / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D004871:Erbium / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry; D008958:Models, Molecular; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D047188:Chalcones; D056831:Coordination Complexes; D008024:Ligands; D049408:Luminescent Agents; D013830:Thiadiazoles; C015700:benzo-1,2,3-thiadiazole; D004871:Erbium; C061481:dibenzoylmethane