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A systematic study for esterification procedures to the synthesis of BINOL diesters is described. Reaction conditions with trifluoracetic acid anhydride (TFAA) and 85% H3PO4 were selected as the best procedure to prepare enantiomerically pure (S)-l.1'-bi-2-naphthol (BINOL) diesters VIII to XI with almost quantitative yields and very short reaction times. [ABSTRACT FROM AUTHOR]

Phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy has become popular for the characterization of P species in environmental samples. However, these are commonly made alkaline (pH  >  13) to facilitate sample comparison and ease peak identification, but this may cause hydrolysis of some compounds. This study examined the chemical shift of known P compounds and supplemented this with published data to determine the viability of examining samples at their native pH, thereby minimizing sample disturbance. A 31 P NMR pH titration of known P compounds resulted in chemical shifts ranging from about -22 to 8 ppm in the pH range 5–13. Categorization and calculation of chemical shifts for over 100 naturally occurring compounds indicated that good distinction between orthophosphate diesters, orthophosphate monoesters, nucleotides, phosphonates, and phosphagens was best at ≥pH 7, but unlikely below this pH. Analysis of several water extracts of soil and dung, overland flow samples, and lake water indicated a wide variety of well-defined peaks that were assigned to orthophosphate, orthophosphate monoesters, orthophosphate diesters, pyrophosphate, polyphosphate, or phosphonates. Changing the sample pH to >13 caused many species (such as phosphonates, orthophosphate diesters, and polyphosphates) to decrease either by hydrolysis or precipitation. Hence, it is recommended that samples be analysed at their native pH but, if poorly resolved, should have their pH raised to ≥7. [ABSTRACT FROM AUTHOR]

Knowledge of organic phosphorus (P) species quantity and distribution in sediments and soils is needed to determine the potential for aquatic and terrestrial organism growth. This can be achieved with 31 P nuclear magnetic resonance spectroscopy (NMR), but resolving peaks within spectra can be problematic because of broadening via paramagnetics, which can cause peaks to overlap. We compared 31 P NMR spectra of NaOH-EDTA extracts of three sediments and three soils to those that had first been pre-treated with Ca-EDTA-dithionite to remove Fe and Mn, paramagnetics that cause broadening of peaks, but leave organic P alone. Broadening of peaks in Ca-EDTA-dithionite pre-treated samples decreased by 46% and revealed peaks that were hidden compared to untreated samples. The spectrum of one pre-treated soil was similar if not better than the same soil that had received pre-treatment with Chelex resin (also to remove paramagnetics). Therefore, pre-treatment with Ca-EDTA-dithionite is recommended as a simple and cost-effective method for improving organic P idenTIFication and determination in subsequent NaOH-EDTA extracts of sediments and soils rich in Fe and Mn. [ABSTRACT FROM AUTHOR]