Structure and vibrational analysis of methyl 3-amino-2-butenoate.

The molecular structure and vibrational spectra of methyl 3-(amino)-2-butenoate (MAB) and its deuterated analogous, D(3)MAB, were investigated using density functional theory (DFT) calculations. The geometrical parameters and harmonic vibrational wavenumbers of MAB and D(3)MAB were obtained at the B3LYP/6-311++G(d,p) level. The calculated vibrational wavenumbers were compared with the corresponding experimental results. The assignment of the IR and Raman spectra of MAB and D(3)MAB was facilitated by calculating the anharmonic wavenumbers at the B3LYP/6-311G(d,p) level as well as recording and calculating the MAB spectra in CCl(4) solution. The assigned normal modes were compared with a similar molecule, 4-amino-3-penten-2-one (APO). The theoretical results were in good agreement with the experimental data. All theoretical and experimental results indicate that substitution of a methyl group with a methoxy group considerably weakens the intramolecular hydrogen bond and reduces the π-electron delocalization in the chelated ring system. The IR spectra also indicate that in the solid state, MAB is not only engaged in an intramolecular hydrogen bond, but also forms an intermolecular hydrogen bond. However, the intermolecular hydrogen bond will be removed in dilute CCl(4) solution.

Effect of Thiobacillus, sulfur, and vermicompost on the water-soluble phosphorus of hard rock phosphate.

Sulfur, organic matter, and inoculation with sulfur-oxidizing bacteria are considered as amendments to increase the availability of phosphorus from rock phosphate. The present study was conducted to evaluate the best combination of sulfur, vermicompost, and Thiobacillus thiooxidans inoculation with rock phosphate from Yazd province for direct application to agricultural lands in Iran. For such study, an experiment was carried out in a completely randomized design with factorial arrangement: Elemental sulfur originated from Sarakhs mine at three rates, 0% (S1), 10% (S2), 20% (S3), vermicompost at two rates, 0% (V1), 15% (V2), and inoculation without (B1) and with (B2) T. thiooxidans, in three replications. The results showed that water-soluble phosphorus (WSP) content was significantly higher in inoculated treatments compared to non-inoculated treatments. Sulfur had a significant effect on WSP. The highest solubility rate of rock phosphate was obtained in 20% of sulfur (S3) treatments and it was 2.4 times more than S1 treatments. Vermicompost also had a significant and positive effect on WSP of rock phosphate dissolution. The results also revealed that the highest concentration of WSP, sulfate and the lowest pH were obtained in treatments with 20% sulfur, 15% vermicompost inoculated with T. thiooxidans (B2S3V2).