Structure, bonding, and aggregation of selenium-containing organolithium species

Abstract

1,3-Dioxo compounds can be prepared from selenium-mediated carbonylation of lithium enolates in the presence of carbon monoxide. Intermediates in this reaction include several organic species that contain both selenium and lithium. The first step in understanding the detailed reaction mechanism is to understand the structure of these intermediates. Like most organolithium compounds, these species can exist as aggregates in solution. The B3LYP density functional theory (DFT) method was used to examine the gas phase and THF solvated structures of these compounds. The calculations showed that each of the compounds forms dimers or higher aggregates in the gas phase. Aggregates are also formed in THF solution, although solvation favors lower aggregates as compared to the gas phase.