The combination of conventional transition-metal-catalyzed coupling (2 e process) and photoredox catalysis (1 e process) has emerged as a powerful approach to catalyze difficult cross-coupling reactions under mild reaction conditions. Reported is a palladium carbodicarbene (CDC) complex that mediates both a Suzuki-Miyaura coupling and photoredox catalysis for C-N bond formation upon visible-light irradiation. These two catalytic pathways can be combined to promote both conventional transition-metal-catalyzed coupling and photoredox catalysis to mediate C-H arylation under ambient conditions with a single catalyst in an efficient one-pot process.
View Article and Find Full Text PDF2,3,9,10-Substituted pentacene tetraesters and pentacene diester-dinitriles were synthesized. These pentacene derivatives underwent an unusual solid state [4 + 4] thermal dimerization with good efficiency and complete stereoselectivity. This observation indicates this series of pentacene derivatives adopt π-π stacking geometry with large mutual overlap in solid state.
View Article and Find Full Text PDFThe simple synthetic development of acyclic pincer bis(pyridine)carbodicarbene is depicted herein. Presented is the first isolated structural pincer carbodicarbene with a C-C-C angle of 143°, larger than the monodentate framework. More importantly, theoretical analysis showed that this carbodicarbene embodies a more allene-like character.
View Article and Find Full Text PDFThe formation of a hitherto unknown three-coordinate dicationic hydrido boron complex is described. Interestingly, supporting ligand carbodicarbene gave unprecedented reaction with BH3 without using more highly electrophilic Lewis acid precursors. Spectroscopic, crystallographic, and computational analysis was performed to understand the electronic features of these species.
View Article and Find Full Text PDFThe charge mobility is a key property in many electro-optical materials, with charge transfer (CT) taking place in a solid matrix of molecules. Large intermolecular electronic interaction is one of the key factors for a good CT rate, which is dependent on both intra- and intermolecular structures. The connection of the molecular structure with the intermolecular CT property would facilitate the search for a new material with desirable CT property, but currently it is still quite limited by the lack of knowledge for intermolecular configurations.
View Article and Find Full Text PDFSelf-assembled, chair-shaped dirhenium(I) macrocyclic compounds featuring the two different bis-chelating quinone dianions (1, L = dhnq(2-); 2, L = dhaq(2-); H(2)dhnq = 6,11-dihydroxy-5,12-naphthacenedione; H(2)dhaq = 1,4-dihydroxy-9,10-anthraquinone) that interface with two fac-Re(CO)(3) cores and a ditopic semirigid N-donor 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)naphthalene (L' = p-NBimM) ligand coordinated to the remaining orthogonal site were prepared in high yields. Their structures were confirmed by single-crystal X-ray diffraction analysis. Electrochemical assessments, using cyclic voltammetry (CV) and UV-vis-NIR spectroelectrochemistry (SEC), revealed the existence of two well-separated, single-electron quinone ligand-centered, reversibly accessible 0, -1, and -2 redox states.
View Article and Find Full Text PDFThe charge transport properties of mer-tris(8-hydroxyquinolinato)aluminum(III) (mer-Alq), which is the most widely used electron transport material in OLED, were investigated by quantum chemistry calculations within the framework of the charge hopping model and Marcus electron transfer theory. Internal reorganization energies of 0.276 and 0.
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