@article {46447, title = {Effect of substitution on the excited state photophysical and spectral properties of boron difluoride curcumin complex dye and their derivatives: a time dependent-DFT study}, journal = {Journal of Photochemistry and Photobiology B-Biology}, volume = {199}, year = {2019}, month = {OCT}, pages = {111595}, type = {Article}, abstract = {

The optical, charge transport and electronic properties of boron difluoride curcumin (BFC) complex have been explored using the DFT (Density Functional Theory) method and B3LYP functional with the combination of 6-31 + G(d,p) as a basis set. The influence of substitution with various electron releasing and withdrawing groups on the above properties is analyzed and discussed in this work. The results reveal that the BFC complex on additional electron releasing substitution experiences redshifts in the optical transitions, and this is correlated with the dipole moment, NBO charges, HOMO-LUMO energy gap. Further, the absorption (lambda(abs)) and emission (lambda(ems)) spectra of substituted and unsubstituted BFCs are calculated using Time-Dependent Density Functional Theory (TD-DFT). The results show that the electron releasing groups strongly influence the absorption and emission spectra of BFC. Electron releasing groups in BFC derivatives generate the wavelength shift (Bathochromic), but the electron-withdrawing groups in BFC don{\textquoteright}t affect the lambda(abs) and lambda(ems) when compare to its original (parent) compound. The output of the research work strongly recommends that the amino, phenyl and N, N{\textquoteright}-dimethylamino derivatives are potential candidates to act as fluorescent materials due to enhance the emission behavior of BFC and also can be used as an electron/charge transport material for organic light-emitting diodes (OLEDs).

}, keywords = {Absorption, Boron difluoride curcumin, Emission, Molecular orbitals, Time-dependent density functional theory}, issn = {1011-1344}, doi = {10.1016/j.jphotobiol.2019.111595}, author = {Selvam, Karthick and Gandhi, Sivaraman and Krishnarnurty, Sailaja and Gopalakrishnan, Gopu} } @article {47022, title = {Theoretical study on cyclophane amide molecular receptors and its complexation behavior with TCNQ}, journal = {Journal of Photochemistry and Photobiology B-Biology}, volume = {203}, year = {2020}, month = {JAN}, pages = {111735}, type = {Article}, abstract = {

Complexation behavior of cyclophane amide molecular receptors towards 7,7,8,8-tetracyanoquinodimethane (TCNQ) studied. TD-B3LYP/6-31 + G(d,p) based density functional theory was employed to investigate the photophysical characteristics of the complexes obtained. Syn isomers of cyclophane amide molecular hosts show preferred conformation over other conformations. Molecular Orbital analysis indicates the electronic structure change, which reflects in the absorption spectra of the cyclophane amide-1@TCNQ, and cyclophane amide-2@TCNQ charge-transfer (CT) complexes. Binding energy studies with B3LYP-D3/6-31 + G (d,p) theory demonstrated that the more effective binding of the pyridine-2,6-dicarboxamide macrocycles than for their isophthalamide analogs. Both the CT complexes show intermolecular bifurcated hydrogen bonding (N-H-(host)center dot center dot center dot N-(guest)center dot center dot center dot H-N-(host)) interactions (2.06 to 2.08 angstrom), and pi((host))center dot center dot center dot pi((guest)) interactions (3.2 to 3.4 angstrom). Calculated BSSE corrected complexation energy (Delta E) be associated with the formation of the inclusion complexes in the range - 28 to similar to 37 kJ mol(-1), indicating spontaneity of host-guest complex formation in both the cases. From the calculated vibrational spectra of these complexes, the formation of inclusion complexes via N - H-(host)center dot center dot center dot N-(guest) and pi((host))center dot center dot center dot pi((guest)) intermolecular interactions established by the frequency shift in the N - H vibrations. Mulliken population analysis performed to recognize the CT process and the variation in charges between the free and complex TCNQ molecules suggests the intermolecular charge transfer. This study indicates that these cyclophane amides can be a decent CT complexation host for the guests like TCNQ.

}, keywords = {Absorption, Charge transfer complex, Cyclophane amides, Electrostatic potential surface, Host-guest, Molecular orbitals, Time-dependent density functional theory}, issn = {1011-1344}, doi = {10.1016/j.jphotobiol.2019.111735}, author = {Sundaram, Soma Sundaram Meenakshi and Karthick, Selvam and Sailaja, Krishnamurty and Karkuzhali, Rajendran and Gopu, Gopalakrishnan} } @conference {48195, title = {Skin mimicking solid optical tissue phantom fulfillment and its characterization}, booktitle = {Photonics in Dermatology and Plastic Surgery 2022}, year = {2022}, publisher = {SPIE}, organization = {SPIE}, address = {1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA}, abstract = {

Skin mimicking optical tissue phantoms are widely used in diagnostics systems for characterization, optimization, routine calibration and validation. In general, solid phantoms are more preferred in comparison to liquid phantoms. Therefore, our aim is to prepare and characterize the solid tissue phantoms having skin equivalent optical properties. In this work, we have used epoxy resin and hardener as a base material and titanium oxide (TiO2) nanoparticles and ink as a scatterer and absorber media, respectively. The total transmission (Tt), collimated transmission (Tc), and diffuse reflectance (Rd) spectra of the developed phantoms were measured with an integrating sphere installed in UV-VIS spectrometer within the wavelength range 400-700 nm. To characterize the optical properties such as absorption (mu(a)), reduced scattering (mu(s){\textquoteright}), and anisotropy factor (g) of the developed tissue phantoms, the numerical model based on Inverse Adding Doubling (IAD) has been used. With various concentrations of absorber and scatterer, a calibration curve was prepared. The calculated experimental optical properties from IAD matched with the predicted intrinsic optical properties of the skin. Thus, the preliminary results suggest that the recipe used in this study may be used as an alternative approach to developing skin mimicking solid optical phantom for diagnostics system applications.

}, keywords = {Absorption, anisotropy factor, scattering, skin mimicking, solid tissue phantom}, isbn = {978-1-5106-4740-4; 978-1-5106-4739-8}, doi = {10.1117/12.2609577}, author = {Kumar, Ajay and Hinge, Sarika and Dixit, Hemant and Kanawade, Rajesh and Kulkarni, Gauri}, editor = {Choi, B and Zeng, H} } @article {49255, title = {Kinetic H2S/CO2 selectivity in an exceptionally sterically hindered amine membrane}, journal = {JOURNAL OF MATERIALS CHEMISTRY A}, volume = {12}, year = {2024}, month = {OCT }, pages = {29138-29144}, type = {Journal Article}, keywords = {Absorption, COMPOSITE MEMBRANES, GAS STREAMS, H2S, Thin-Film}, issn = {2050-7488}, doi = {10.1039/d4ta04997g}, author = {Rao, Shraavya and Deng, Xuepeng and Zou, Changlong and Prasad, Babul and Han, Yang and Lin, Li-Chiang and Ho, W. S. Winston} } @article {49384, title = {Leveraging machine learning to dissect role of combinations of amino acids in modulating the effect of zinc on mammalian cell growth}, journal = {BIOTECHNOLOGY PROGRESS}, volume = {40}, year = {2024}, month = {MAY}, type = {Journal Article}, keywords = {Absorption, Cytotoxicity, ENTEROCYTES, HISTIDINE}, issn = {8756-7938}, doi = {10.1002/btpr.3436}, author = {Pandey, Ujjiti and Madhugiri, Indrani and Gadgil, Chetan and Gadgil, Mugdha} }