RESUMO
In this work, an intramolecular carbon nitride (CN)-based quaternary homojunction functionalized with pyridine rings is prepared via an in situ alkali-assisted copolymerization strategy of bulk CN and 2-aminopyridine for efficient visible light hydrogen generation. In the obtained structure, triazine-based CN (TCN), heptazine-based CN (HCN), pyridine unit incorporated TCN, and pyridine ring inserted HCN constitute a special multicomponent system and form a built-in electric field between the crystalline semiconductors by the arrangement of energy band levels. The electron-withdrawing function of the conjugated heterocycle can trigger the skeleton delocalization and edge induction effect. Highly accelerated photoelectron-hole transfer rates via multi-stepwise charge migration pathways are achieved by the synergistic effect of the functional group modification and molecular quaternary homojunction. Under the addition of 5 mg 2-aminopyridine, the resulting homojunction framework exhibits a significantly improved hydrogen evolution rate of 6.64 mmol g-1 h-1 with an apparent quantum efficiency of 12.27% at 420 nm. Further, the catalyst verifies its potential commercial value since it can produce hydrogen from various real water environments. This study provides a reliable way for the rational design and fabrication of intramolecular multi-homojunction to obtain high-efficient photocatalytic reactions.
RESUMO
In the title racemic compound, ethyl 4-(4-di-methyl-amino-phen-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate, the common structural features in this type of compound, such as the flat-boat conformation of the 1,4-di-hydro-pyridine (1,4-DHP) ring, the envelope conformation of the fused cyclo-hexa-none, and the substituted phenyl ring at the pseudo-axial position and orthogonal to the 1,4-DHP ring, are present. In the crystal, mol-ecules are linked via N-Hâ¯O and C-Hâ¯O hydrogen bonds, forming layers parallel to the (10) plane.