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We have investigated the structural and thermodynamic parameters of group‐14 substituted germylenes and their reactivity toward the H2 molecule using density functional theory (DFT). We conducted the detailed Kohn–Sham molecular orbital (KS‐MO) analysis to quantify the effective factors behind the increased reactivity of germylenes in going from C to Sn as substituents. The quantum theory of atoms in molecules (QTAIM), non‐covalent interaction (NCI), and natural bond orbital (NBO) analyses revealed the nature of bonds and interactions and demonstrated the reactivity trend of germylenes in the presence of H2. The results showed that in going from C to Sn, the reactivity increased due to an improvement in σ‐donation interaction between the filled lone‐pair orbital of the germylene (LPGe) and the σ*‐orbital of H2, which decreased the reaction barrier (∆E‡). As the germylene substitution was varied from C to Sn, a significant reactivity was observed for the germylene toward the H2. This observation was caused by a reduction in steric repulsion between the germylene and the H2 and less activation energy due to the higher σ‐donation and lower back‐donation. We have presented the reactivity of new and rationally designed germylenes toward H2 using various analyses that will serve as a guide for the activation of small molecules such as H2, which is employed in many subsequent reactions. [ABSTRACT FROM AUTHOR]

The aim of this research is a comparison of the efficiency of six commercially available cyclodextrins (CDs) to improve the solubility and oral bioavailability of atorvastatin calcium (ATV‐Ca) and rosuvastatin calcium (ROV‐Ca) drugs in aqueous media. Inclusion complexes of both drugs with non‐toxic α‐CD, β‐CD, γ‐CD, HP‐β‐CD, M‐β‐CD, and maltodextrin were prepared in a 1:1 stoichiometry via the kneading method. To reach the best CD, various experimental and computational analyses were performed including phase solubility, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), hydrogen‐1 nuclear magnetic resonance (1HNMR), carbon‐13 nuclear magnetic resonance (13CNMR), and molecular docking calculations. The M‐β‐CD turned out to be the best substrate for the micro‐encapsulation of both drugs. Also, ATV showed a higher tendency than ROV to form inclusion complexes with CDs. Molecular docking studies showed that HP–β–CD and M‐β‐CD are the most suitable substrates for the formation of inclusion complexes, respectively. Our research showed that the β‐CD is not necessarily the most efficient substrate for increasing solubility based on previous reports in the literature; meanwhile, the other employed substrates in this study can show acceptable performances in this regard. According to our results, M‐β‐CD is the best substrate for the micro‐encapsulation of both drugs, which increases their solubility in water. [ABSTRACT FROM AUTHOR]

In our previous report (J. Phys. Org. Chem., 2019), we discussed novel silicon photosensitizers (PSs) in psoralen ultraviolet A (PUVA) therapy. Continuing this quest, we have scrutinized a new brand of PSs, via density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) methods. These PSs show intense narrow absorption peaks in the therapeutic window with very high molar absorption coefficients (ε). Calculated vertical ionization potential (VIP) and vertical electron affinity (VEA) values indicate that our PSs can produce reactive oxygen species (ROS) through type I mechanism. Also, energies of the first triplet excited states (T1) and spin–orbit coupling (SOC) constants verify the possibility and efficiency of type II mechanism for the generation of the singlet excited state of molecular oxygen (1O2). The results introduce new potential PSs in PDT and PUVA therapy. [ABSTRACT FROM AUTHOR]

We aim to develop novel four‐membered cyclosilylenes that contain one (1 and 2), two (3), three (4), and four (5) numbers of Si atoms at the M06/6–311 + G*, B3LYP/aug‐cc‐PVTZ, and MP2/3–21G levels of theory. These structures show high stability and turn out as minima on their energy surfaces for showing no imaginary frequency. Structural and thermodynamic parameters, including bond length, divalent bond angle, singlet‐triplet energy gap (ΔES‐T), highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gap (ΔEH‐L), proton affinity (PA), complexation energy (ΔECom) with CO molecule, nucleophilicity (N), chemical potential (μ), and natural charges, are assessed. The final order of singlet stability appears in the order 1 > 2 > 3 > 4 > 5 at three levels of theory. [ABSTRACT FROM AUTHOR]

In our previous report (J. Phys. Org. Chem., 2017), we discussed the dual behavior of gold nanocluster (Au3 NC), where it scavenged reactive oxygen species (ROS) while promoted their generation to a lesser extent. Continuing this quest, we investigate the effects of Au3 NC on common reactive nitrogen species (RNS: ON˙ and ON˙O) and their precursors (ONH and ONOH, respectively), at B3LYP/LACVP+* level of theory. We compare the results with those of prevalent ROS (HO˙ and HOO˙) and their precursors (HOH and HOOH, respectively). To this end, various parameters are probed such as binding energy (Eb), bond dissociation energy (BDE), bond lengths, Mullikan spin density (MSD), critical point (CP) eigenvalues (atoms in molecules [AIM] analysis), and natural bond orbital (NBO) analysis including natural population analysis (NPA) and change of charge transfer energy (ΔECT). Our results show that in the presence of Au3 NC, BDEs of the NH and OH bonds increase in both ONHAu3 (1) and ONOHAu3 (2) compared with their free forms (ONH and ONOH, respectively). In other words, the tendency to dissociate these bonds and form their corresponding RNS (1′ and 2′) decreases in the presence of gold. This is exactly the opposite of what is observed for the OH bonds in HOHAu3 (3), HOOHAu3 (4), and their corresponding ROS (3′ and 4′). Therefore, we can conclude that gold shows a different behavior in the face of RNS compared with ROS where it is a better scavenger of ROS than RNS. [ABSTRACT FROM AUTHOR]