Constructing spin crossover-fluorescence bifunctional iron(ii) complexes based on tetraphenyl ethylene-decorated AIEgens

Abstract

Investigating spin crossover (SCO)-fluorescence bifunctional materials and establishing their structure-function relationships are attractive topics in chemistry and materials science. However, it remains challenging to preserve the fluorescence and SCO properties...

Construction of spin crossover-fluorescence bifunctional iron(ii) complexes with modified bis(pyrazole)pyridine ligands

“…The decreasing trend of fluorescence intensity in the range of 260–300 K is similar to that of complexes that have been reported before. 33,37 Then the fluorescence intensity turns to increase slowly in the 300–380 K temperature range, and finally decreases again upon further increase in temperature. At 400 K, the fluorescence enhancement effect caused by the spin transformation is no longer significant, and the fluorescence thermal quenching effect begins to dominate, leading to the decrease of fluorescence intensity.…”

“…The bpp-type ligands L 1 and L 2 were synthesized according to the procedure described in the literature. [37][38][39][40] Detailed synthesis procedures of the ligands are described in Scheme S1 (ESI †). The structure and purity of L 1 and L 2 were characterized by 1 H NMR, mass spectrometry and UV-vis spectra (Fig.…”

“…[30][31][32] To date, a few studies have been conducted on SCO-fluorescence synergy based on the bpp system. [33][34][35][36][37] Concerning this, herein, we designed two fluorescent group-modified bpp ligands: 4-(naphthalen-1-yl)-2,6-bis(1-pyrazolyl)pyridine (L 1 ) and (E)-2,6-bis(1-pyrazolyl)-4-(2-(pyren-1-yl)vinyl)pyridine (L 2 ). Two new SCO-fluorescence bifunctional Fe II complexes, namely [Fe(L 1 ) 2 ](ClO 4 ) 2 (1) and [Fe(L 2 ) 2 ](ClO 4 ) 2 Á2.63CH 2 Cl 2 (2), were obtained by the reaction of the ligands and iron(II) perchlorate (Scheme 1).…”

Measurement of Reverse-Light-Induced Excited Spin State Trapping in Spin Crossover Systems: A Study Case with Zn1−xFex(6-mepy)3tren(PF6)2·CH3CN; x = 0.5%

“…In the case of very strong cooperative interactions between the centres, the abrupt transitions are accompanied by a hysteretic behaviour, leading to bistability, which is essential for applications such as memory devices [7]. Other applications include sensing by magnetism [8,9], optical diffraction [10], luminescence [11,12], guest adsorption [13], or surfaces, thin films, and a patterned structure [14]. Alternatively, the UV-VIS/NIR excitation of the LS species at low temperatures Crystals 2024, 14, 210 2 of 10 leads to the population of the HS state.…”

“…Crystals 2024, 14, x FOR PEER REVIEW 2 of 10 luminescence [11,12], guest adsorption [13], or surfaces, thin films, and a patterned structure [14]. Alternatively, the UV-VIS/NIR excitation of the LS species at low temperatures leads to the population of the HS state.…”