Persistent bidirectional optical switching in the 2D high-spin polymer {[Fe(bbtr)3](BF4)2}∞.

Area of Science:

• Materials Science
• Coordination Chemistry
• Solid-State Physics

Background:

• The iron(II) coordination network {[Fe(bbtr)(3)](BF(4))(2)}(∞) features covalently linked 2D layers.
• Iron(II) centers typically remain in the high-spin (HS) state down to low temperatures (10 K).

Purpose of the Study:

• To investigate the light-induced spin-state transitions in the {[Fe(bbtr)(3)](BF(4))(2)}(∞) coordination network.
• To explore the potential for optical switching and bistability in this material.

Main Methods:

• Employing light irradiation at specific wavelengths to induce spin-state changes.
• Utilizing spectroscopic techniques to monitor spin-state transitions (near-IR for HS to LS, visible for LS to HS).

Main Results:

• Quantitative conversion between high-spin (HS) and low-spin (LS) states of iron(II) centers was achieved via light irradiation.
• The compound exhibits true light-induced bistability below 100 K.
• Demonstrated reversible switching between spin states using distinct light wavelengths.

Conclusions:

• The {[Fe(bbtr)(3)](BF(4))(2)}(∞) coordination network displays light-induced spin-state bistability.
• This material holds potential for persistent bidirectional optical switching at accessible temperatures.
• The findings contribute to the development of molecular switches and optical data storage materials.