Synthesis, structure and aromaticity of metallapyridinium complexes

Abstract

The first rhena-analogues of pyridinium (cyclopropametalla-2-isoquinolinium complexes) are obtained from o-ethynyl benzonitriles. Structural analysis and DFT calculations confirm their aromatic nature. Compared to rhenapyrylium, rhenapyridinium has a slightly stronger Hückel...

α-Rhenabenzofuran with nonaromatic T0and aromatic S1states

“…The addition of PMePh 2 on the coordinated CuC bond gave rhenacyclopropene complex Ib. 9 Fast proton transfer from acidic -OH to the three-membered metallacyclopropene unit generated the delocalized rhenafuran ring. Density functional theory (DFT) 10 studies also confirm the paramagnetic properties of 2.…”

Adaptive σ aromaticity in the rhenacyclopropene rings

“…Recently, Li and co-workers synthesized metallapyridinium derivatives and found that the unsaturated rhenacyclopropene ring displays σ aromaticity in the S 0 state. 41 Thus, a series of rhenacyclopropene derivatives (Figure 1) are constructed and optimized in the S 0 and T 1 states. The bond lengths of complexes 1-8 are provided in Figure 2.…”

“…40 Recently, Li and co-workers reported aromaticity in the rhenacyclopropene ring of metallapyridinium derivatives in the S 0 state. 41 How about the aromaticity in this rhenacyclopropene ring in the T 1 state? If so, the rhenacyclopropene ring could possess adaptively aromaticity.…”

“…Could other rhenacyclopropene rings display adaptive aromaticity? In order to address these issues, we construct a series of rhenacyclopropene rings based on the previous studies (Figure 1) 40,41 and carry out a systematic study on their aromaticity in both the S 0 and T 1 states via density functional theory (DFT) calculations.…”

“…Until 2020, our group reported adaptive σ aromaticity in the four‐membered ring of tetraatomic boron species 39 and in the metallacyclopropene ring (Figure 1). 40 Recently, Li and co‐workers reported aromaticity in the rhenacyclopropene ring of metallapyridinium derivatives in the S 0 state 41 . How about the aromaticity in this rhenacyclopropene ring in the T 1 state?…”