Luminescence thermometry and field induced slow magnetic relaxation based on a near infrared emissive heterometallic complex

The 1 : 1 : 1 reaction of YbCl3 center dot 6H(2)O, K-3[Co(CN)(6)] and bpyO(2) in H2O has provided access to a complex with formula [YbCo(CN)(6)(bpyO(2))(2)(H2O)(3)]center dot 4H(2)O (1) in a very good yield while its structure has been determined by single-crystal X-ray crystallography and characterised based on elemental analyses and IR spectra. Magnetic susceptibility studies showed the complex to be a field induced single molecule magnet, as confirmed by mu-SQUID measurements. CASSCF calculations confirm the existence of a m(J) = 7/2 ground state, with rather large transverse components, responsible for the fast relaxation characteristic of compound 1 at zero DC field, which is reduced upon application of DC fields. Moreover, a combination of luminescence studies along with CASSCF calculation allows the identification of the band structure of the complex, which is ultimately related to its electronic properties. Compound 1 operates as a luminescent thermometer in the 125-300 K range with a maximum relative thermal sensitivity of approximate to 0.1% K-1 at 180 K.

Automated summary

The complex [YbCo(CN)6(bpyO2)2(H2O)3]·4H2O synthesized from the reaction of YbCl3·6H2O, K-3[Co(CN)6], and bpyO2 has been characterized and shown to exhibit field-induced single molecule magnet behavior and high-temperature luminescence sensitivity.