Synergetic Spin Crossover and Fluorescence in One‐Dimensional Hybrid Complexes

Abstract

Hybrid materials integrated with a variety of physical properties, such as spin crossover (SCO) and fluorescence, may show synergetic effects that find applications in many fields. Herein we demonstrate a promising postsynthetic approach to achieve such materials by grafting fluorophores (1-pyrenecarboxaldehyde and Rhodamine B) on one-dimensional SCO Fe II structures. The resulting hybrid materials display expected one-step SCO behavior and fluorescent properties, in particular showing a coupling between the transition temperature of SCO and the temperature where the fluorescent intensity reverses. Consequently, synergetic effect between SCO and fluorescence is incorporated into materials despite different fluorophores. This study provides an effective strategy for the design and development of novel magnetic and optical materials.

Confined Crystallization of Spin‐Crossover Nanoparticles in Block‐Copolymer Micelles

“…[4,8] Furthermore,t he physical properties of either the complex itself (e.g.c olor,m agnetism, structure) [5,9] or associated properties in multifunctional systems (e.g. conductivity, [10] luminescence [11] )change upon switching and raise their interest for applications,e specially as sensors. [12] In order to realize such applications,aneasy processing of the complexes is indispensable for the integration in devices.T his task (including down-sizing) is challenging as most of the SCO properties,e specially the observation of wide thermal hysteresis loops,d epend on the crystal packing.…”

Iron(II) Spin Crossover Coordination Polymers Derived From a Redox Active Equatorial Tetrathiafulvalene Schiff-Base Ligand

“…Below 28 K, the χ M T product sharply decreases, attaining 0.71 cm 3 K mol −1 at 2 K, which can be owing to the presence of zero-field splitting of the residual HS Fe II ions or antiferromagnetic interaction among Fe II centres ( Suleimanov et al, 2015 ). However, at 350 K, the χ M T product for 2 is 2.16 cm 3 K mol −1 , which is much lower than the expected product for three isolated HS Fe II centres ( Supplementary Figure 12 ), indicating that the LS Fe II centres are dominant in 2 ( Garcia et al, 2011 ; Wang et al, 2015 ; Schönfeld et al, 2020 ; Zappe et al, 2020 ).…”

Acidity-Driven Bidirectional Room-Temperature Spin-State Switch and Fluorescence Modulation of a Mononuclear Fe(II) Complex

“…Synergetic effects of the two functions is a goal as it allows modulation of fluorescence emission upon spin state changes, and conversely, spin-state "read out" by monitoring the emission intensity. Coordination of SCO active metal ions with fluorescent ligands [17][18][19][20][21][22][23][24][25] and construction of fluorescent-SCO composite [24][25][26][27][28][29][30][31] are two well-developed strategies. Abnormal temperaturedependent fluorescence variations were observed in the SCO region due to different energy transfers in the two states and, in most cases, an enhanced fluorescence in the HS state was observed.…”