Experimental and theoretical study on structure and spectroscopic properties of 2-bromo-3-N-(N',N'-dimethylformamidino) benzanthrone

Emergence of practical fluorescence in a confined space of nanoporous silica: significantly enhanced quantum yields of a conjugated molecule

The fluorescence of benzanthrone, which is a conjugated molecule bearing a carbonyl group, is activated by confinement in a pore with a diameter close to the molecular size. An intense emission originating from the aromatic character π-π* transition is achieved through suppression of the nonradiative n-π* transition by strong hydrogen bonding between carbonyl groups and silanol groups with a micropore-filling effect in the nanospace.

Comparison of the Benzanthrone Luminophores: They Are Not Equal for Rapid Examination of Parafasciolopsis fasciolaemorpha (Trematoda: Digenea)

Luminescent derivatives of benzanthrone are becoming more useful based on their light-absorbing and fluorescent-emitting properties. Our previous studies showed that luminescent staining properties of the same benzanthrone dye differ for variable parasite samples. Therefore, two types of benzanthrone dyes were prepared. One has a strongly basic amidine group and a halogen atom, and the other has an amide moiety and a tertiary amine group. Trematoda Parafasciolopsis fasciolaemorpha is a liver fluke of a moose (Alces alces) and has a significant influence on the health and abundance of the moose population. Staining protocols for parasite P. fasciolaemorpha specific organ or organ systems imaging are mostly time-consuming and labor-intensive. The study aimed to compare the fixation technique and the staining protocol by synthesized benzanthrone luminescent dyes to determine detailed morphology, anatomical arrangement of the organ systems and gross organization of the muscle layers of P. fasciolaemorpha using confocal laser scanning microscopy. Luminophores were tested for samples fixed in different fixatives. Developed dyes and staining protocol resulting in imaging of all parts of trematode without additional sample preparation procedures, which usually are required for parasite examination. Obtained results confirmed that the most qualitative results could be reached using 3-N-(2-piperidinylacetamido)benzanthrone dye which has amide moiety and a tertiary amine group. Based on obtained results, 3-N-(2-piperidinylacetamido)benzanthrone gave more qualitative parasite visualization than 2-bromo-3-N-(N′,N′-dimethylformamidino)benzanthrone.

Quantum chemical computations and photophysical spectral features studies of two coumarin compounds

An attempt was made to determine the ground state and excited state dipole moments and quantum chemical computations of two coumarin compounds, namely 3-hydroxy-3-[2-oxo-2-(2-oxo-2H-chromen-3-yl)-ethyl]-1,3-dihydro-indol-2-one (3HOCE) and 3-[2-(8-methoxy-2-oxo-2H-chromen-3-yl)-2-oxo-ethylidene]-1,3-dihydro-indol-2-one (3MOCE). Both compounds displayed a red shift with enhancement in solvent polarity. The larger excited state dipole moment indicated the more polar nature of the selected compounds in the excited state than in the ground state. Kinetic stability and chemical reactivity of the selected compounds were studied with help of the quantum chemical properties of the compounds such as frontier molecular orbital analysis using density functional theory calculations with B3LYP/6-311+G (d, p) basis sets. Molecular electrostatic potential, Mulliken charges, natural bond orbital, and nonlinear optical properties were further studied. NBO analysis showed proton transfer within the selected donor-acceptor, depicting the large energy of stabilization for the compounds. The calculated Fukui function inferred the local softness and electrophilicity indices of used solute compounds.