The recent implementation of new environmental legislations led to a change in the manufacturing of composites that has repercussions on printed wiring boards (PWB). This in turn led to alternate processing methods (e.g., lead-free soldering), which affected the required physical and chemical properties of the additives used to impart flame retardancy. This review will discuss the latest advancements in phosphorus containing flame retardants for electrical and electronic (EE) applications and compare them with commercially available ones. The mechanism of degradation and flame retardancy of phosphorus flame retardants in epoxy resins will also be discussed.

To assess the effects of molecular symmetry on the phase transitions of columnar liquid crystals, we prepared a family of 19 discotic mesogens. This series of dibenzophenazine derivatives allowed us to compare the differences in phase transitions between sixteen pairs of isomers that differed in terms of their overall symmetry. It was found that the more symmetrical isomer had a significantly higher melting temperature in all but one case, whereas symmetry appeared to have a lesser impact on clearing temperature. A similar relationship between symmetry and melting point is also observed for triphenylene-based discotic mesogens; in these systems, the clearing points show a stronger dependence on molecular symmetry.

This article discusses the behavior of seven organophosphorus compounds under Atherton–Todd conditions. Therefore, the reactivity and selectivity of different (phen)oxaphosphinines, dioxaphosphinines, dioxaphosphinanes, and diphenylphosphine oxide with three nucleophiles were systematically studied. The results prove the versatility of the Atherton–Todd reaction to a broad range of organophosphorus compounds with different phosphorus environments and reactive PH bonds. The nucleophiles studied in this article were chosen as model substrates for amines and alcohols. Because organophosphorus molecules are important and versatile compounds, for a broad field of applications, novel synthetic approaches are of interest to both academia and industry. As an example, the single‐step synthesis of the bridged 1,3‐phenylene bis(diphenylphosphinate) with potential flame‐retardant properties was added to this study. In addition, the reaction is utilized for the synthesis of a novel organophosphorus anhydride. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:216–222, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21006

Organophosphorus compounds such as 6H-dibenzo[c,e][1,2]oxaphosphinine 6-oxide (DOPO, 1) and its derivatives are important and versatile compounds for a broad field H coupling patterns are discussed and compared with the derivatives possessing different chemical environments around the phosphorus atom. In addition, we compared our results with density functional theory calculations. Even though the prediction of NMR data of organophosphorus compounds via molecular modeling is limited, this study presents a method that yields good results for this class of heterocycles. This knowledge should help to quickly assign NMR spectroscopic data of other DOPO (1) derivatives and can be extrapolated to organophosphorus compounds in general.

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