Theoretical investigation into the coordination of R‐/S‐asymmetric uranyl–salophens containing six‐membered ring lactam with cis−/trans‐cyclohexylamines

• Published in: Applied organometallic chemistry Vol. 32; no. 7
• Main Authors: Yang, Liang‐Liang, Kong, Xiang‐He, Wu, Zhi‐Lin, Lin, Ying‐Wu, Liao, Li‐Fu, Nie, Chang‐Ming
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.07.2018
• Subjects: Amides; Chemistry; Coordination compounds; coordination selectivity; Density functional theory; Mathematical analysis; Molecular chains; molecular recognition; Receptors; Recognition; R‐/S‐asymmetric uranyl–salophens; Steric hindrance
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.4387

A six‐membered ring lactam derivative was introduced in a parallel manner into uranyl–salophens with R/S configuration (R‐/S‐AUSRLs), which were used as receptors to coordinate with guests of cis−/trans‐methylcyclohexylamines (cis−/trans‐MCHAs). Using density functional theory calculations at the B3LYP/6‐311G** level and RECP, an insight into the coordination complexes of the R‐/S‐AUSRLs with cis−/trans‐MCHAs was obtained. The results showed that the U atoms of receptors could coordinate with the N atoms of four kinds of cis−/trans‐1,2 or − 1,4 guests, but the two kinds of cis−/trans‐1,3 guests could not be converged by the same method in the process of structural optimization due to steric hindrance, and thus the cis−/trans‐1,3 guests could not be coordinated with the R‐/S‐AUSRLs. The mode of coordination of the R‐/S‐AUSRLs with the guests displayed a significant difference. And the change of R‐AUSRL coordination ability to the cis−/trans‐MCHAs was very large, but that of S‐AUSRL was small. Overall, the stability of the R‐series coordination complexes was higher than that of the corresponding S‐series coordination complexes, and the R‐AUSRL receptor had better coordination selectivity and higher molecular recognition to the cis−/trans‐MCHA guests than the S‐AUSRL receptor. However, the coordination ability of S‐AUSRL with the cis−/trans‐MCHAs was stronger than that of R‐AUSRL. It was expected that these results could provide insightful information and theoretical guidance for understanding the molecular recognition of R‐/S‐AUSRLs for cis−/trans‐type cyclohexylamine derivatives. A six‐membered ring lactam was introduced into uranyl–salophens with R/S configuration (R‐/S‐AUSRLs), which were used as receptors to coordinate with cis−/trans‐methylcyclohexylamine (cis−/trans‐MCHA) guests. The coordination of R‐/S‐AUSRLs with cis−/trans‐MCHAs showed an obviously different selectivity. It is expected that the results could provide insightful information and theoretical guidance for understanding the molecular recognition of R‐/S‐AUSRLs for cis−/trans‐type cyclohexylamine derivatives.