Sn(iv) Schiff base complexes: triplet photosensitizers for photoredox reactions

Abstract

We present the synthesis and characterization of a series of four fluorescent Sn(iv) Schiff base complexes, which also possess long-lived triplet excited states. The complexes absorb visible light (λmax = 420 to 462 nm) and the optical properties are easily tunable without laborious synthetic elaboration. The triplet excited states are not luminescent, but can be observed and followed using nanosecond transient absorption spectroscopy. The lifetimes of the triplet excited states are on the order of 500 μs-10 ms in PMMA matrices. The triplet state energies were estimated via energy transfer reactions with a series of organic triplet acceptors. In addition, the photoexcited complexes react with electron donors and acceptors in solution. These results demonstrate the potential for the development of photosensitizers based on main group elements with high spin orbit coupling constants.

Schiff base supported mononuclear organotin(IV) complexes: Syntheses, structures and fluorescence cell imaging

“…[2] However, recent research interests are focusing on synthesis of Schiff base complexes of main group metals. [3] In this context, organotin(IV) complexes of Schiff bases are growing continuously. [4] Such ligands have offered a great variety of structural diversities such as monomeric, dimeric, polymeric and one or two-dimensional frameworks.…”

“…These complexes mainly included transition metal ions . However, recent research interests are focusing on synthesis of Schiff base complexes of main group metals . In this context, organotin(IV) complexes of Schiff bases are growing continuously .…”

Enhancement of photoresponse property of perovskite solar cell by aluminium chloride (AlCl3)

“…This study reveals multiple absorbance present for the matrix (figure 6). The absorbance spectra of tin doped perovskite film show peaks near 290, 350, 385 and 450 nm which are due to characteristics band gap excitations of tin oxide [21], ITO [22], rutile phase of TiO 2 [23] and tin complexes in probable perovskite film [24] respectively. Whereas, the nature of absorbance spectra of aluminium doped perovskite film is slightly different as it shows sharp absorbance peak near 262 nm following a broad shoulder near 550 nm due to the presence of entrapped Al 3+ ions in the host matrix [25] and aluminium (III) complexes forming probable perovskite films [26,27] respectively.…”

Recent advancements of fluorescent tin(iv) complexes in biomedical molecular imaging

“…As well as having these luminescence properties, tin metal complexes are relatively simple to synthesize, easy to use, environmentally friendly, and more economical than other metal complexes. There is growing evidence that fluorescent tin and organotin complexes are effective in the fields of photonics, 9 optoelectronics, 10 and biomedical applications, such as organic light-emitting diodes (OLEDs), 11 in vitro sensing of ions, [12][13][14][15][16] silk fibroin staining, [17][18][19] in vitro imaging by laser scanning confocal microscopy, and two-photon laser scanning fluorescence microscopy in tissues, and living animals. 8,10 Furthermore, organotin complexes are now widely used in ''biomedical molecular imaging'', which gives the concept of combining ''diagnosis'' and ''therapeutic'' in an emerging trend for cancer treatment in the current era.…”