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Carbon allotropes have contributed to all aspects of people's lives throughout human history. As emerging carbon-based low-dimensional materials, graphyne family members (GYF), represented by graphdiyne, have a wide range potential applications due to their superior physical and chemical properties. In particular, graphdiyne (GDY), as the leader of the graphyne family, has been practically applied to various research fields since it was first successfully synthesized. GYF have a large surface area, both sp and sp2 hybridization, and a certain band gap, which was considered to originate from the overlap of carbon 2pz orbitals and the inhomogeneous π-bonds of carbon atoms in different hybridization forms. These properties mean GYF-based materials still have many potential applications to be developed, especially in energy storage and catalytic utilization. Since most of the GYF have yet to be synthesized and applications of successfully synthesized GYF have not been developed for a long time, theoretical results in various application fields should be shared to experimentalists to attract more intentions. In this Review, we summarized and discussed the synthesis, structural properties, and applications of GYF-based materials from the theoretical insights, hoping to provide different viewpoints and comments. [ABSTRACT FROM AUTHOR]

Investigates the nature of the cation-pi interaction as a binding force in the binding of acetylcholine to acetylcholinesterase. Ab initio calculations for the complexes of tetramethylammonium cation with various substances; Comparison of Hartree-Frock and Moller-Plesset second-order perturbation treatments; Role of electron correlation effect.

The intramolecular magnetic couplingconstant (J) values of sets of diradicals linkedto bis-DTDA, OVER, and NN radicals(DTDA, OVER, and NN groups) through an aromatic coupler were studiedby unrestricted density functional theory calculations (UB3LYP/6-311++G(d,p)).Among 15 aromatic couplers, 9 compounds with an odd number of carbonatoms along its spin coupling path were found to interact ferromagneticallyupon coupling with bisradicals while the other 6 couplers with aneven number of carbon atoms along its spin coupling path give riseto antiferromagnetic coupling. The overall trends in the strengthof magnetic interactions of aromatic couplers were preserved for DTDA,OVER, and NN groups so that the trend can be utilized as an indexfor the magnetic strength of a given coupler. It was found that thedifferences in the nucleus-independent chemical shift (NICS), bondorder of connecting bonds, and Mulliken atomic spin density at connectedatoms between triplet and BS states are closely related to the intramolecularmagnetic behavior. 2,4- and 2,5-phosphole couplers exhibit the strongestintramolecular ferromagnetic and antiferromagnetic interactions among15 aromatic couplers when linked to diverse bisradicals. [ABSTRACT FROM AUTHOR]

Detailsof the reaction mechanism for the Ru–PNN pincer complex catalyzedamidation from an alcohol and an amine proposed by Milstein et al.was elucidated using M06 density functional theory calculations. Inaddition, the bifunctional double hydrogen transfer (BDHT) mechanismfor the dehydrogenative oxidation step was investigated for comparison.Finally, the BDHT mechanism was found to be preferred over the β-Helimination pathway that was proposed by Milstein et al. On the basisof the analysis of NBO charges and orbital interactions of intermediatesand transition states, we designed a new catalyst with the additionof an electron-donating substituent (−NEt2), whichprovided much reduced energy barriers and a lower potential energysurface along both mechanisms. [ABSTRACT FROM AUTHOR]

Organic semiconductors to date having cofacial stacking motif are scarce compared to those having herringbone motif. Recently, Ahmed and co-workers have reported a series of novel n-type bisindenoanthrazolines (BIDAs) [Chem. Mater. 2010, 22, 5786], among which DADF and DADK adopt different slipped cofacial arrangements exhibiting distinct electron transport abilities. Here, we performed computational studies to understand the relationship between charge transport and molecular packing for these BIDAs molecules. This work focuses on the intrinsic molecular factors required for efficient and long-range charge transfer. Unlike the previous studies only focusing the charge injection barriers or the carrier mobilities, herein, we present the notion that lower electron injection barrier and higher intrinsic electron mobility should be both satisfied to achieve better n-type OFETs. We also note that the actual mobility can be significantly underestimated due to the limitation of the space-charge limited current method. Through computational modeling, we rationalized the superior electron conductivity of DADK and also shed light on the favorable or undesirable properties for efficient charge transport of BIDAs. Another key finding is that the intrinsic electron and hole mobilities are quite deviated from each other rather than comparable in current mobility calculations. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) calculations were performed using a MPWB1K functional to interpret the charge transport (CT) properties of stacked annelated β-trithiophene molecules. The goal was to help understand how the chemical composition, face-to-face stacking, intra- and intermolecular correlations, and the applied electric field affect the CT properties of this organic semiconductor compared with those of the edge-to-face "herringbone" motif. The variations in the frontier molecular orbitals, energy gap, nonadiabatic electron attachment energies (EAE), and vertical detachment energies (VDE) were investigated under an external electric field as a function of the number of stacked layers (n). Two possible CT pathways, monomer-to-monomer (MM) and dimer-to-dimer (DD) transports, were postulated to determine the charge carrier conductivities of these molecules. The results highlight that the intermolecular electronic couplings and electrostatic interactions can significantly affect the stacking geometry, even in more extended structures; displaced stacks with smaller interlayer spacing resulted in more compact stacking and, thus, higher CT efficiency; face-to-face stacking geometries can help to reduce the energy gap and VDE. Despite the fact that common thiophene-based oligomers adopting edge-to-face herringbone motifs exhibited p-type (hole-transporting) characters, the face-to-face stacked models based on annelated β-trithiophenes exhibited remarkably increased n-type (electron-transporting) performances. The electric field in the z-direction produced a small influence on the DD charge transport, whereas both electron and hole mobilities decreased dramatically in the MM case. More importantly, in MM charge transport, the electric field increases the hole mobility so that it is higher than that of the electron. [ABSTRACT FROM AUTHOR]

A major challenge in photodynamic cancer therapy (PDT) is avoiding PDT-induced hypoxia, which can lead to cancer recurrence and progression through activation of various angiogenic factors and significantly reduce treatment outcomes. Reported here is an acetazolamide (AZ)-conjugated BODIPY photosensitizer (AZ-BPS) designed to mitigate the effects of PDT-based hypoxia by combining the benefits of anti-angiogenesis therapy with PDT. AZ-BPS showed specific affinity to aggressive cancer cells (MDA-MB-231 cells) that overexpress carbonic anhydrase IX (CAIX). It displayed enhanced photocytotoxicity compared to a reference compound, BPS, which is an analogous PDT agent that lacks an acetazolamide unit. AZ-BPS also displayed an enhanced in vivo efficacy in a xenograft mouse tumor regrowth model relative to BPS, an effect attributed to inhibition of tumor angiogenesis by both PDT-induced ROS generation and CAIX knockdown. AZ-BPS was evaluated successfully in clinical samples collected from breast cancer patients. We thus believe that the combined approach described here represents an attractive therapeutic approach to targeting CAIX-overexpressing tumors. [ABSTRACT FROM AUTHOR]

Two donor–acceptor (D–A)medium band gap polymers, P1and P2, alkoxyphenylthiophene(APTh) linked benzodithiophene (BDT) as an electron-rich unit and1,3-di(2′-bromothien-5′-yl)-5-(2-ethylhexyl)thieno[3,4-c]pyrrole-4,6-dione (TPD) (A1) or [5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole] (BT) (A2) as an electron-deficientunit, have successfully been synthesized via microwave-assisted Stillepolymerization and utilized for bulk heterojunction (BHJ) polymersolar cells (PSCs). P1shows a well-distinguished absorptionshoulder between 590 and 620 nm attributed to the π–πstacking of a polymer backbone; such kind of absorption shoulder isnot observed in P2, indicating that the P1has more planar structure than that of P2. This isdue to the fact that the sulfur atom of thiophene spacer and the oxygenatom of carbonyl groups in TPD have more pronounced intramolecularnoncovalent interactions (INCI) in P1than that of thesulfur atom of thiophene spacer and the oxygen atom of alkoxy groupsof BT in P2. The bulk heterojunction polymer solar cells(BHJ PSCs) were fabricated with the configuration of ITO/PEDOT:PSS/polymer(P1or P2):PC71BM/LiF/Al. The P1device shows better photovoltaic performance with open-circuitvoltage (Voc) of 0.91 V and the powerconversion efficiency (PCE) of 4.19% than the P2device(Voc: 0.71 V; PCE: 1.88%) in neat blendfilms under the illumination of AM 1.5G (100 mW/cm2). Upontreating the active layers containing P1and P2with methanol, the PCE of the P1device is increasedfrom 4.19 to 7.14%. In contrast, the PCE of the P2deviceis decreased from 1.88 to 1.82%. Space charge limited current mobility,atomic force microscopy, transmission electron microscopy, time-of-flightsecondary ion mass spectrometry, and impedance spectroscopy studiesstrongly support the enhanced PCE for the P1device isattributed to the increased mobility, nanoscale morphology, and reducedresistance upon methanol treatment; these favorable properties forthe P1polymer are highly correlated with the planarityof the backbone. [ABSTRACT FROM AUTHOR]

Ithas recently been shown that the types of intramolecular magneticinteractions of diradical systems can be changed by the types of radicalgroup: syn-group (or α-group) and anti-group (or β-group).The aim of this study is to establish a useful scheme to understandand explain the intramolecular magnetic interactions in diradicalsystems regardless of radical groups and the topology of a coupler.We investigated the intramolecular magnetic coupling constant (J) of six oxoverdazyl diradicals (i–vi) coupled with a benzene ring based on the unrestrictedDFT calculations. On the basis of our results, we devised a simplebut useful scheme by combining the spin alternation rule and the conceptof radical group classification. Consequently, it was found that thecalculated Jvalues and plots of spin density distributionswere consistent with our proposed scheme. In addition, we discussed the closed-shell singlet (CS) state and the dihedralangle effect on Jvalues in detail to comprehensivelyunderstand the magnetic interactions of diradical systems. Our schemecan provide the basic framework to design future organic high-spinmolecules and organic magnetic materials. [ABSTRACT FROM AUTHOR]

Novel,stimulus-responsive supramolecular structures in the formof fibers, gels, and spheres, derived from an azobenzene-containingbenzenetricarboxamide derivative, are described. Self-assembly oftris(4-((E)-phenyldiazenyl)phenyl)benzene-1,3,5-tricarboxamide(Azo-1) in aqueous organic solvent systems results insolvent dependent generation of microfibers (aq DMSO), gels (aq DMF),and hollow spheres (aq THF). The results of a single crystal X-raydiffraction analysis of Azo-1(crystallized from a mixtureof DMSO and H2O) reveal that it possesses supramolecularcolumnar packing along the baxis. Data obtainedfrom FTIR analysis and density functional theory (DFT) calculationsuggest that multiple hydrogen bonding modes exist in the Azo-1fibers. UV irradiation of the microfibers, formed in aq DMSO, causescomplete melting while regeneration of new fibers occurs upon visiblelight irradiation. In addition to this photoinduced and reversiblephase transition, the Azo-1supramolecules display areversible, fiber-to-sphere morphological transition upon exposureto pure DMSO or aq THF. The role played by amide hydrogen bonds inthe morphological changes occurring in Azo-1is demonstratedby the behavior of the analogous, ester-containing tris(4-((E)-phenyldiazenyl)phenyl)benzene-1,3,5-tricarboxylate (Azo-2) and by the hydrogen abstraction in the presence offluoride anions. [ABSTRACT FROM AUTHOR]

New phenothiazine based organic dyes were prepared for visible-light-driven organic transformations. The 3,7-disubstituted phenothiazine derivatives showed visible light absorption and reversible one-electron oxidation behavior. In the presence of 0.5 mol % of 3,7-disubstituted phenothiazines, primary benzylamines showed oxidative coupling under visible light irradiation from a blue LED. The electronic effect of substituents in phenothiazine dyes was observed in catalytic activities. The mechanistic pathway of oxidative coupling was discussed based on the detection of H2O2after the reaction. [ABSTRACT FROM AUTHOR]

A new series of neutral radicals (DP1–DP6) based on diazaphenalenyl were designed via heteroatomic modifications. As spin sources, the designed radicals were implemented in four different diradical model systems (models I, II, III, and IV) by changing the reference radical and the linkage, and their magnetic interactions between the designed radicals and the reference radical were investigated by using density functional theory calculations. The trend in strength of magnetic interactions of radicals was found to be identical in different model systems. The strength of magnetic interactions could be understood by spin density distributions and NICS values. Our results will be helpful in designing and controlling the organic magnetic materials incorporated with diazaphenalenyl derivatives. In particular, as a new family of spin source radical, DP3could be a potential candidate in designing new organic magnetic materials due to its strong magnetic coupling and high stability in diradical systems. [ABSTRACT FROM AUTHOR]

A new and efficient system for the selective recovery of platinum ions from conventional cheap transition metal mixtures was developed. We found that the selone is reactive toward the conventional acids. Mesoporous silica functionalized by reaction of selone showed excellent selectivity to platinum ions among various transition metal ions. [ABSTRACT FROM AUTHOR]