Competition between Intra and Intermolecular Triel Bonds. Complexes between Naphthalene Derivatives and Neutral or Anionic Lewis Bases

Molecules

SteveScheiner¹  Mariusz Michalczyk²  Wiktor Zierkiewicz² 

[1] Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA;Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland;

关键词: triel bond;    intramolecular triel bond;    mp2;    mep;    π-hole;   

DOI  :  10.3390/molecules25030635

来源: DOAJ

【 摘 要 】

: A TrF₂ group (Tr = B, Al, Ga, In, Tl) is placed on one of the α positions of naphthalene, and its ability to engage in a triel bond (TrB) with a weak (NCH) and strong (NC⁻) nucleophile is assessed by ab initio calculations. As a competitor, an NH₂ group is placed on the neighboring C^α, from which point it forms an intramolecular TrB with the TrF₂ group. The latter internal TrB reduces the intensity of the π-hole on the Tr atom, decreasing its ability to engage in a second external TrB. The intermolecular TrB is weakened by a factor of about two for the smaller Tr atoms but is less severe for the larger Tl. The external TrB can be quite strong nonetheless; it varies from a minimum of 8 kcal/mol for the weak NCH base, up to as much as 70 kcal/mol for CN⁻. Likewise, the appearance of an external TrB to a strong base like CN⁻ lessens the ability of the Tr to engage in an internal TrB, to the point where such an intramolecular TrB becomes questionable.

【 授权许可】

Unknown