Resumo:
Phosphate esters are an important group of chemical compounds. They are naturally
found and intrinsically related to life since are involved in genetic and energy storage.
However, there is a concern about the use of anthropogenic phosphate esters emerges due to
their persistence, toxicity especially to the nervous system and exponential rise of its uses. In
this work phosphate esters with linear carbonic chain (methyl, ethyl, and propyl), were
simulated in neutral and anionic forms using MP2, B3LYP, and M06-2X as methodology.
Results point out that MP2 is the best methodology, since it was energetically more accurate
compared to DFT. For conformational results, all methodologies give similar results. After
the oxygen deprotonation, a structural and electronic rearrangement took place, pushing
deprotonated oxygen away from each other, compensated by the approximation of oxygen
esters (and consequently carbonic chains). Results of Monomethyl phosphate (MMP) indicate
that the anomeric effect (hyperconjugation) has a great influence on species stability.
Conformational analysis of neutral MMP allowed identifying maximum and minimum energy
points, including second-order saddles points. Many pathways for reactions are possible with
these configurations. The molecular description was performed characterizing atomic
interaction and distance. This analysis involved many tools, such as topological or orbitals
(Molecular or Natural) composition. No significant participation of P-d electrons was
founded. Since phosphate ester hydrolysis occurs in water medium and this reaction could be
catalyzed by metals, especially lanthanides. A polymeric base of polymethacrylate (maximum
of 10 monomers) was simulated in neutral and anionic forms, with and without solvation, and
linearly of consecutive constructed. These simulations indicated a consistent behavior
regarding the chain size. Furthermore, high-charged chains tend to elongate more than lower
ones. Concerning the lanthanide coordination to reference monomers, the use of semiempirical software generates results compatible with the literature. The coordination seems to
tend to an ideal number (9), where distances metal-ligand stabilizes. When the monomer is
not able to supply the metal with ligands sites to reach the previously number, water
molecules complete the coordination sphere.
