Solvent-assisted monomeric molecular structure of the phosphate diester and the synthesis of menthol-based phosphate diesters

Abstract

Phosphate diesters are well known to form intermolecular H-bonded dimeric structures in their solid-state. Recently, we reported 2,6-(CHPh) 2-4-iPr-phenyl substituted phosphate diester exists as H-bonded monomeric molecular structure along with water dimer in the solid-state. Herein we report 2,6-(CHPh) 2-4-iPr-phenyl substituted phosphate diester forms a monomeric molecular structure in the solid-state upon cocrystallization with dimethylformamide, DMF (Me 2 NCHO). The-CHO group of DMF simultaneously acts as an H-bond acceptor to P-OH and an H-bond donor to P=O moieties. We also used the alcohols, ROH (R = Me, Et, iPr, and tBu), for crystallisation of 2,6-(CHPh) 2-4-iPr-phenyl substituted phosphate diester. In these instances, solvent-incorporated dimeric structures are found in the solid-state. We also report the syntheses and molecular structures of anionic phosphate diesters of 2,6-(CHPh) 2-4-iPr-phenyl substituted phosphate diester possessing various counter cations. Moreover, we also report the syntheses and molecular structures of phosphate diesters based on (-)-menthol, (?)-menthol and (?)/(-)-menthol. These exist as H-bonded dimers in the solid-state.

Supramolecular aggregation in sterically encumbered monoarylphosphates and their H-bonded adducts: multigram synthesis of elusive 2,6-di-tert-butylphenyl phosphate

“…12,20,24 The incorporation of sterically encumbered substituents on the phosphate monoester and diester can afford hydrogen bonded dimer 25,26 and water dimer encapsulated monomer, respectively. 27,28 Previous work from our laboratory has revealed that the interaction of amines with organosilanols can significantly alter the hydrogen bonding network of parent silanols. 29 In order to explore such kind of hydrogen bonding interactions, we further demonstrated that the incorporation of an amino group at the para position of 2,6-diisopropylphenyl phosphate leads to hitherto unknown supramolecular aggregates.…”

“…12,20,24 The incorporation of sterically encumbered substituents on the phosphate monoester and diester can afford hydrogen bonded dimer 25,26 and water dimer encapsulated monomer, respectively. 27,28…”