Exploring non-covalent interactions for metformin-thyroid hormones stabilization: Structure, Hirshfeld atomic charges and solvent effect

Exploration of the Intriguing Photovoltaic Behavior for Fused Indacenodithiophene-Based A-D-A Conjugated Systems: A DFT Model Study

Many researchers are engaged nowadays in developing efficient photovoltaic materials to accomplish the demand of modern technology. Nonfullerene small molecular acceptors (NF-SMAs) show potential photovoltaic performance, accelerating the development of organic solar cells (OSCs). Herein, the first theoretical designing of a series of indacenodithiophene-based (IDIC1-IDIC6) acceptor chromophores was done by structural tailoring with various well-known acceptors from the recently synthesized IDICR molecule. For the selection of the best level of density functional theory (DFT), various functionals such as B3LYP, M06-2X, CAM-B3LYP, and ωB97XD with the 6-311G(d,p) basis set were used for the UV-visible analysis of IDICR. Consequently, UV-visible results revealed that an interesting agreement was found between experimental and DFT-based values at the B3LYP level. Therefore, quantum chemical investigations were executed at the B3LYP/6-311G(d,p) level to evaluate the photovoltaic and optoelectronic properties. Structural tailoring with various acceptors resulted in a narrowing of the energy gap (2.245-2.070 eV) with broader absorption spectra (750.919-660.544 nm). An effective transfer of charge toward lowest unoccupied molecular orbitals (LUMOs) from highest occupied molecular orbitals (HOMOs) was studied, which played a crucial role in conducting materials. Further, open circuit voltage (V _oc) analysis was performed with respect to HOMO _PBDB-T -LUMO_ACCEPTOR, and all of the derivatives exhibited a comparable value of voltage with that of the parent chromophore. Lower reorganization energies in titled chromophores for holes and electrons were examined, which indicated the higher rate of mobility of charges. Interestingly, all of the designed chromophores exhibited a preferable optoelectronic response compared to the reference molecule. Therefore, this computed framework demonstrates that conceptualized chromophores are preferable and might be used to build high-performance organic solar cells in the future.

Molecular engineering of indenoindene-3-ethylrodanine acceptors with A2-A1-D-A1-A2 architecture for promising fullerene-free organic solar cells

Considering the increased demand and potential of photovoltaic devices in clean, renewable electrical and hi-tech applications, non-fullerene acceptor (NFA) chromophores have gained significant attention. Herein, six novel NFA molecules IBRD1-IBRD6 have been designed by structural modification of the terminal moieties from experimentally synthesized A2-A1-D-A1-A2 architecture IBR for better integration in organic solar cells (OSCs). To exploit the electronic, photophysical and photovoltaic behavior, density functional theory/time dependent-density functional theory (DFT/TD-DFT) computations were performed at M06/6-311G(d,p) functional. The geometry, electrical and optical properties of the designed acceptor molecules were compared with reported IBR architecture. Interestingly, a reduction in bandgap (2.528-2.126 eV), with a broader absorption spectrum, was studied in IBR derivatives (2.734 eV). Additionally, frontier molecular orbital findings revealed an excellent transfer of charge from donor to terminal acceptors and the central indenoindene-core was considered responsible for the charge transfer. Among all the chromophores, IBRD3 manifested the lowest energy gap (2.126 eV) with higher λmax at 734 and 745 nm in gaseous phase and solvent (chloroform), respectively due to the strong electron-withdrawing effect of five end-capped cyano groups present on the terminal acceptor. The transition density matrix map revealed an excellent charge transfer from donor to terminal acceptors. Further, to investigate the charge transfer and open-circuit voltage (Voc), PBDBT donor polymer was blended with acceptor chromophores, and a significant Voc (0.696-1.854 V) was observed. Intriguingly, all compounds exhibited lower reorganization and binding energy with a higher exciton dissociation in an excited state. This investigation indicates that these designed chromophores can serve as excellent electron acceptor molecules in organic solar cells (OSCs) that make them attractive candidates for the development of scalable and inexpensive optoelectronic devices.

Alkylammonium Cation Affinities of Nitrogenated Organobases: The Roles of Hydrogen Bonding and Proton Transfer

Alkylammonium cation affinities of 64 nitrogen-containing organobases, as well as the respective proton transfer processes from the alkylammonium cations to the base, have been computed in the gas phase by using DFT methods. The guanidine bases show the highest proton transfer values (191.9-233 kJ mol^-1 ) whereas the cis-2,2'-biimidazole presents the largest affinity towards the alkylammonium cations (>200 kJ mol^-1 ) values. The resulting data have been compared with the experimentally reported proton affinities of the studied nitrogen-containing organobases revealing that the propensity of an organobase for the proton transfer process increases linearly with its proton affinity. This work can provide a tool for designing senors for bioactive compounds containing amino groups that are protonated at physiological pH.