Substituent effects of fused Hammick germylenes: Estimating the stability and reactivity using density functional theory. (12th July 2021)

• Record Type: Journal Article
• Authors: Elveny, Marischa; Alrazzak, Nour Abd; Aljeboree, Aseel M.; Alkaim, Ayad F.; Ebadi, Abdol Ghaffar
• Is Part Of: Journal of physical organic chemistry. Volume 34:Number 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-07-12
• Subjects: band gap -- electrophilicity -- Hammick germylene -- nucleophilicity -- stability; Chemistry, Physical organic -- Periodicals; 547.1
• DOI: 10.1002/poc.4262
• Languages: English
• ISSNs: 0894-3230

Abstract

Abstract: In this theoretical survey, we compared and contrasted the substituent influences on stability, aromaticity, band gap, atomic charge distribution, and reactivity of 54 singlet and triplet fused Hammick germylenes derived from germabenzopyridine‐4‐ylidene as well as the synthesized five‐ and six‐membered ones by Herrmann and Driess, respectively. Investigations show (1) the lowest and the highest singlet–triplet energy difference (Δ Ε s–t ) is demonstrated by fusion of two phosphole rings and two furan rings in ortho ‐positions (35.6 and 253.6 kJ/mol, respectively) compared with those of the synthesized germylenes (208.8 and 179.9 kJ/mol, respectively). (2) Whereas fusion of benzene, pyridine, phosphinine, and phosphole rings thermodynamically destabilizes the corresponding germylenes, fusion of pyrrole, furan, and thiophene rings stabilizes the corresponding germylenes. (3) The tendency of substituent influences in number and size of rings is arranged by two five‐membered rings > one five‐membered rings > one six‐membered rings > two six‐membered rings. (4) While pyrrole, furan, and thiophene rings kinetically stabilize the corresponding germylenes, other rings destabilize their germylenes with respect to germapyridine‐4‐ylidene and the isolated germylene's Driess. (5) All singlet Hammick germylenes reveal lower nucleophilicity and softness, also higher electrophilicity, chemical potential, and global hardness than their scrutinized triplet states. (6) We are waiting for experimental testing and verifications to fuse heterocyclic rings to the germapyridine‐4‐ylidene's plane in a favorable spatial position to act not only as π ‐electron giver but also σ‐electron receiver. Abstract : In this theoretical survey, we compared and contrasted the substituent influences on stability, aromaticity, band gap, atomic charge distribution, and reactivity of 54 singlet and triplet fused Hammick germylenes derived from germabenzopyridine‐4‐ylidene as well as the synthesized five? and six?membered ones by Herrmann and Driess, respectively.