Showing papers by "Riina Aav published in 2022"

Carbonyl hypoiodites from pivalic and trimesic acid and their silver(I) intermediates.

Abstract: The first tris(O-I-N) carbonyl hypoiodites have been synthesised based on trimesic acid and pyridine or 4-methylpyridine, with their structures definitively confirmed by single crystal X-ray diffraction (SCXRD). The more soluble carbonyl hypoiodites based on pivalic acid have also been studied via NMR, SCXRD, and computational analyses, enabling the study of the direct silver(I) precursor and intermediates of the resulting carbonyl hypoiodites generated using a range of substituted pyridines.

Self-Assembly of Chiral Cyclohexanohemicucurbit[n]urils with Bis(Zn Porphyrin): Size, Shape, and Time-Dependent Binding

Abstract: In order to investigate the ability of bis(zinc octaethylporphyrin) (bis–ZnOEP) to discriminate cyclohexanohemicucurbit[n]urils (cycHC[n]) of different shapes and sizes, the self-assembly of barrel-shaped chiral cycHC[n] with bis–ZnOEP was studied by various spectroscopic methods (absorption, fluorescence, circular dichroism (CD), and NMR). While the binding of 6-membered cycHC[6] induced a tweezer-like conformation followed by the formation of anti-form of bis–ZnOEP upon further addition of cycHC[6], the interaction of 8-membered cycHC[8] is more complex and proceeds through the featured syn-to-anti conformational change of bis–ZnOEP and further intermolecular self-assembly via multiple noncovalent associations between cycHC[8] and bis–ZnOEP. Whilst bis–porphyrins are known to be effective chemical sensors able to differentiate various guests based on their chirality via induced CD, their ability to sense small differences in the shape and size of relatively large macrocycles, such as chiral cycHC[6] and cycHC[8], is scarcely examined. Both studied complexes exhibited characteristic induced CD signals in the region of porphyrin absorption upon complexation.

Editorial: Stimuli-Responsive Emissive Organic and Metal-Organic Compounds

Abstract: Light is an indispensable part in the production and living of human society, and the development of light-emitting materials is of great significance for high-tech innovations. Indeed, the exploitation of high-performance luminogenic materials has opened a new avenue to scientific advancement and societal development. For example, Chen et al. reported a fluorene-based dinuclear gold(I) complex. This complex demonstrated a remarkable aggregation-induced white-light emission feature, and it emitted high brightness solid-state and thin-film white luminescence. Furthermore, its thin-film white-light emission quantum yield was up to 65.42%, which enabled this gold(I) complex to serve as a potential candidate for white OLED (Chen et al., 2014). Benzobisthiadiazole (BBT) belongs to a typical near-infrared emissive unit, and the photoluminescence (PL) of numerous BBT derivatives lie in the second near-infrared wavelength ranges (NIR-II, 1,000–1,700 nm). The NIR-II-emissive nature of this type of compounds is beneficial to biomedical applications. Sun et al. elaborately designed a multipurpose nano-agent by incorporating a supramolecular Pt (II) metallacycle and a BBT-modified NIR-II-emissive organic dye into multifunctional melanin dots possessing photoacoustic and photothermal properties, and this prepared nano-agent displayed superior dual-modal imaging-guided chemo-photothermal synergistic therapy effect (Sun et al., 2019). Ding et al. prepared a high-efficiency nanotheranostic agent by introducing a hexagonal organoplatinum (II) metallacycle and a BBT-based NIR-II molecular dye into a FDAapproved commercial theranostic agent, and this obtained nano-cocktail could be applied for effective cancer imaging and therapy (Ding et al., 2019). Huang et al. summarized a variety of benzobisthiadiazole-functionalized semiconducting polymers, and their resulting nanoparticles could be used for NIR-II photoacoustic imaging. Luminescent chemosensors possess a number of advantages in practical applications, such as high sensitivity and selectivity, versatility, and superior real-time detection capacity. In order to prepare multifunctional luminescent chemosensors, plenty of specific functional recognition units have been introduced to luminogenic organic compounds and organometallic complexes, and the resultant functionalized molecules are capable of forming PL responses to metal ions, pH, anions and biomolecules. For example, Hu et al. synthesized a pyrimidinone-containing Schiff base FPS by a classical aza-Wittig reaction, which could be applied to selectively and sensitively detect Zn with the limit of detection of 1.19 × 10 mol/L. Furthermore, the resulting FPS-Zn could further serve as a high-efficiency chemosensor for Cu. Therefore, this interesting Schiff base Edited and reviewed by: Iwao Ojima, Stony Brook University, United States