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The fluorescence imaging technique is becoming a useful tool in the natural and life sciences. Commercial biomarkers are available; however, some disadvantages exist like high isolation cost, low-temperature storage, photodegradation, and low yields. Here two new fluorescent molecular rotors (SB-B 2 and SB-B2 3) derived from Boron Schiff bases (BOSCHIBAs) were synthesized and characterized by NMR (1H and 13C), UV/Vis, and fluorescence spectroscopy. The crystal structure of SB-B2 3 by X-ray diffraction showed a binuclear complex and C2 symmetry. Both compounds showed viscochromic and thermochromic properties. The binuclear rotor 3 showed a greater luminescence intensity increase than the mononuclear one at the highest level of viscosity (90%). From the remarkable findings and to our best knowledge this is the first time low cytotoxicity BOSCHIBAs exhibit selective fluorescent staining of endoplasmic reticulum in HeLa cells and HUVECs. [ABSTRACT FROM AUTHOR]

This research describes the theoretical study of the adsorption of lithium clusters on graphene and the ability to capture hydrogen molecules. The results of the studied structures showed that the [Li 1 C 54 H 18 ]+ system is capable of accepting three hydrogen molecules showing adsorption energies of 0.12 eV. On the other hand, it is important to note that in [Li n C 54 H 18 ] n = 2–6 systems, the lithium atoms that do not interact with the graphene surface, they can adsorb up to four hydrogen molecules. The [Li 6 C 54 H 18 ]4H 2 system presented a higher adsorption energy value of 0.31 eV. Finally, the Li–H 2 interactions were characterized by a NBO analysis, which showed that hydrogen atoms are the donors and lithium atoms are the acceptors. [Display omitted] • The computational studies reveal physisorption of H 2 molecule on [Li 1 C 54 H 18 ]+ system. • The studied structures showed that the [Li 1 C 54 H 18 ]+ system is capable of accepting 3H 2. • The lithium clusters into the graphene surface, facilitates that H 2 can adsorb easily. [ABSTRACT FROM AUTHOR]

The interaction of small gas molecules as H2, N2, CO, H2S, NH3, SO2 and CH4 on Li-functionalized graphitic carbon nitride was investigated by using the density functional theory, to explore their gas adsorption properties. The calculated Eads values of all gas molecules on [Li g-C3N4]+ show that these gas molecules present favourable interaction with the lithium atom coordinated on the sheet. NH3 and SO2 molecules present strong interactions, with Eads values of −18.60 and −9.50 kcal mol−1. The natural bond orbital analysis indicates that donor orbitals belong to the lone pairs of oxygen, nitrogen, sulphur and carbon atoms from SO2, N2, NH3, H2S, CO molecules, and acceptor orbitals (LP*) from the lithium atom. Computational studies suggest that H2, N2, CO, H2S, NH3, SO2 and CH4 molecules on [Li g-C3N4]+ present physisorption. [ABSTRACT FROM AUTHOR]

The fluorescent silk fibroin (FSF) is useful in a number of biomedical applications. However, some FSFs are less useful for medical applications because they are derived from toxic compounds. Here we report for the first time a fast (∼20 min), ultrasonic assisted, eco-friendly synthesis of four fluorescent organotin Schiff compounds using the corresponding aldehyde, benzoic hydrazide, and diorganotin oxide (1: MeO-L-SnPh2, 2: tBu2-L-SnPh2, 3: HO-L-SnPh2, and 4: HO-L-SnBu2). These compounds were fully characterized by NMR spectroscopy (1H, 13C, and 119Sn), HRMS, and UV/Vis and fluorescence spectroscopy. Single crystal X-ray diffraction investigations of complexes 1 and 2 are also reported. The as-prepared organotin Schiff compounds exhibit fluorescence at ambient temperature with good photophysical properties (fluorescence quantum yields Φ: 18–55%). These organotin compounds serve as fluorescent dyes in silk fibroin (Bombyx mori). The organotin dyed fluorescent silk fibroin showed a uniform staining, high viability, and good capacity to retain organotin compounds which might be used as innocuous scaffolds in tissue engineering. [ABSTRACT FROM AUTHOR]

In this paper, we report the synthesis and characterization of new boron compounds derived from dithiooxamides. The compounds were characterized by NMR (1H and 13C), UV-vis, fluorescence spectroscopy, and high resolution mass spectrometry. The crystal structure of the mononuclear boron compound was determined by single-crystal X-ray diffraction analysis. The photophysical properties of the boron compounds were investigated, and we found moderate fluorescence emission (compound 2 ΦF: 4.07% and compound 4 ΦF: 2.89%). We also observed that the mononuclear complex presented greater stability. Compound 4 showed interesting luminescent properties; in solid state, it exhibited an increase in fluorescence by mechanostimuli by changing to a bright red color, and also in solution, it showed a decrease in fluorescence intensity when oxygen and air were supplied to the solution. [ABSTRACT FROM AUTHOR]

We report the design, synthesis, and characterization of two new fluorescent molecular rotors of boron derived from Schiff bases: (2,4,8,10-tetra-tert-butyl-6-phenyldibenzo[d,h][1,3,6,2]dioxazaboronine (3) and 1,4-bis(2,4,8,10-tetra-tert-butyldibenzo[d,h][1,3,6,2]dioxazaboronin-6-yl)benzene (4), as well as the free ligand 2-[[(3,5-di-tert-butyl-2-hydroxyphenyl)imino]methyl]-4,6-di-tert-butylphenol 1. All compounds were fully characterized by NMR (¹H, 11B, and 13C), IR, UV/vis, fluorescence spectroscopy, and high-resolution mass spectrometry. The crystal structures of 3 and 4 showed tetracoordinated boron atoms with semiplanar skeleton ligands. The free rotation of the fluorescent molecular rotor, only observed in the binuclear compound, was decreased with increasing viscosity, while the quantum yield was increased. Interestingly, the property of reversible thermochromism was found in organoboron 4 in the solid state. DFT calculations to determine the both complexes have free rotation around the CPh-B1 bond. The boron compounds 3 and 4 have shown low cytotoxicity activity in cell line A-431 and low green staining in cells. [ABSTRACT FROM AUTHOR]

The reaction of the di-lithiated oxamide of 1 with two equivalents of SnCl2 provided the tin trans-oxamide 3. In solution, spectroscopic analysis suggests exclusively the formation of a trans-oxamide ( trans- 3). However, the solid state shows an atypical cis-oxamide ( cis- 3), where the oxamide fragment acts as an anti-Janus head ligand. An 119Sn-NMR variable temperature experiment ([D8]THF) of the trans-oxamide ( trans- 3) was performed however, at lower temperature no additional signal was observed, which confirmed the absence of a dynamic equilibrium. Dispersion-corrected density functional calculations revealed that the cis conformation of this tin(II) oxamide complex is more stable than the trans isomer by 1.4 kcal ·mol-1. [ABSTRACT FROM AUTHOR]

The fluorescence imaging technologies are becoming the most powerful and noninvasive diagnostic tools in cellular biology and modern medicine where abnormal cell arrangements are associated with diseases. Thus, these techniques require new fluorescent dyes with excellent chemical, physical, and photophysical properties. A series of four new Boron Schiff bases (1–4) has been prepared by condensation between phenylboronic acid with the corresponding ligand. The compounds were characterized by NMR (1H, 13C, and 11B), UV/vis, fluorescence spectroscopy, and high‐resolution mass spectrometry. The crystal structures of three compounds showed tetracoordinated Boron atoms with semiplanar skeleton ligands. Interesting organoboron response to viscosity on their fluorescence (Φ: more than 3‐fold). Additionally, compounds 1 and 2 were found to serve as a fluorescent dye for cell imaging (B16F10, CaCo, and A‐431 cells) since it has the capability to rapidly accumulate within the cells and gave bright green fluorescence, it showed low cytotoxicity activity and high photostability in solution. Additionally, the compounds have also been investigated using DFT. Organoboron response to viscosity on their fluorescence. Additionally, boron compounds 1 and 2 were found to serve as a fluorescent dye for cell imaging (B16F10, CaCo, and A‐431 cells) since it has the capability to rapidly accumulate within the cells and gave bright green fluorescence, it showed low cytotoxicity activity and high photostability. [ABSTRACT FROM AUTHOR]