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Showing 1 to 20 of 33 for “"Phosphorus compounds"”.
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Polarity Inversion in Silicon and Phosphorus Compounds
… herein describes efforts to design silicon and phosphorus compounds of inverse polarity with respect to conventional reactivity by accessing oxidation states that are atypical for these p-block elements. This umpolung approach affords novel reactivity that was previously unavailable to silicon …
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A structure-reactivity study of selected phosphorus compounds
… centre. When the expected leaving group on the phosphorus atom has an acidic α-proton the nucleophile approaches adjacent to the leaving group as a result of a strong interaction between the α-proton and the nucleophile. This tendency had been found previously and is confirmed by this study. …
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Synthesis and properties of potentially liquid crystalline phosphorus compounds
… reports the synthesis of a number of novel phosphorus(IIl) molecules and an investigation into their possible liquid crystalline phase behaviour. Trigonal pyramidal phosphines together with the corresponding tetrahedral phosphine oxides, with three alkoxybiphenyl groups attached to a central …
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On the coordination chemistry of pentavalent (σ⁴, λ⁵) phosphorus compounds
… the synthesis of a variety of pentavalent organophosphorus compounds and their applications as ligands to address important problems in coordination chemistry. This research encompasses two main themes: (1) the asymmetric synthesis of enantiopure α-alkylbenzylphosphonic acids, and the use of …
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Structure and synthesis of some phosphorus compounds of potential biological activity
Bibliography: 109-110.
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Bond activation and catalysis by nontrigonal tricoordinate and tetracoordinate phosphorus compounds
… catalytic reactivity of [sigma]³- and [sigma]⁴ -phosphorus compounds with distorted nontrigonal structures. Specifically, a rare example of N-H oxidative addition to a planar, C2v-symmetric P(III) center is described in Chapter 2. The kinetics and computational studies implicate a noncanonical, …
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Expanding Deoxygenative Transformations of Alcohols by Phosphorus Compounds Through Geometric Deformation
Tricoordinate phosphorus (σ³-P) compounds act as strong O-atom acceptors in many deoxygenative transformations by forming strong P=O bonds in phosphine oxides. While typical trigonal σ³-P compounds are nucleophilic, it has been demonstrated that lowering the C₃ᵥ-symmetry of σ³-P compounds to …
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Advancements in the synthesis of distorted tricoordinate phosphorus compounds and their use as platforms in reductive chemistries
… reactivity of geometrically distorted [sigma]³ phosphorus compounds as well as attempts to synthesis new C₂v distorted [sigma]³ phosphorus compounds. Chapter two will describe the synthetic efforts towards synthesizing new [sigma]³ phosphorus compounds to provide new platforms to expand the …
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Phosphorus in the Environment and its Role in Anaerobic Iron Corrosion
Phosphorus chemistry controls key aspects of eutrophication, microbial nutrition, corrosion and other environmental processes. It is commonly assumed that phosphorus occurs exclusively as phosphate (+5) in nature. In fact, although phosphate is undoubtedly dominant in many systems, phosphorus …
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DRIVING NOVEL REACTIVITY BY DECODING THE ELECTRONIC STRUCTURE OF NONTRIGONAL PHOSPHORUS TRIAMIDES
Trivalent phosphorus compounds are ubiquitous throughout synthesis, with applications ranging from ligands in transition metal chemistry to mediating organic transformations. Their reactivity is canonically regarded as nucleophilic by virtue of the electronic structure governed by their three-fold …
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(De)fluorination of Organic Substrates Mediated by Nontrigonal Phosphorus Triamide
… and physiological properties to organic compounds. Therefore, the number of industrially synthesized products containing fluorine has seen a substantial increase in recent decades. The strategies to access organofluorine compounds include two opposite approaches: 1) (nucleophilic, …
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Replacing Sp2 Hybridized Carbon Centers with Phosphorus
… between the chemistry of molecular carbon and phosphorus compounds has fascinated chemists for decades and has even led to phosphorus being coined “the Carbon Copy.” A guiding tenet in organic chemistry is that carbon can be bonded to a maximum of four other atoms to satisfy the octet rule. By …
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Thermal degradation of organophosphorus compounds.
… spectra and mass spectra of 1,3,5-triazine and phosphorus compounds of relevance to the topic is briefly discussed. The behaviour of heated samples of menazon on paper (one and two dimensional) and thin layer (analytical and preparative) chromatography is described. Details are given of the …
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The effects of a phosphate detergent ban on a biological nutrient removal plant and anaerobic digester
… study investigated the effects of the detergent phosphorus ban implemented on January 1, 1988 in Virginia, on the treatment streams of the York River Wastewater Treatment Plant, a biological nutrient removal (BNR) system. Evaluation of the available historical data indicated that the influent …
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Dipyrazolylphosphanes in Condensation and P–N/P–P Bond Metathesis Reactions
Phosphorus plays a crucial role in modern p-block chemistry.1 One reason for that is the diagonal relationship between phosphorus and carbon.2 Comparable to carbon and its chemistry, phosphorus tends to form homoatomic bonds, which is explainable by the relatively high P–P single bond energy (ca. …
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Propene oligomerization over steam dealuminated and boron and phospherous modified ZSM-5
ZSM-5 was modified with boron and phosphorus compounds in an attempt to improve the selectivity of the catalyst with respect to the linearity of the liquid product of propene oligomerization. Boron was incorporated into the zeolite framework by inclusion in the synthesis gel. Boralite catalysts …
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Characterization of Reduced Phosphorus Metabolism in Alcaligenes Faecalis WM2072 and Xanthobacter Flavus WM2814
… herein describe the characterization of reduced phosphorus metabolism in two recently isolated bacteria. These bacteria were found by performing enrichments to isolate organisms that could utilize reduced phosphorus compounds as their sole phosphorus source. Two of these isolates that grew well …
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Kinetics of the release and precipitation of phosphorus in anaerobic digesters sequencing biological phosphorus removal systems
The extent of release and precipitation of phosphorus stored in the poly-phosphate granules of microorganisms present in anaerobic digesters sequencing a biological phosphorus removal (BPR) activated sludge system was examined. The research was conducted at the York River Wastewaster Treatment …
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