Piperazine phosphate

Piperazine phosphate (H2O) [18534-18-4] M 197.6. Crystd twice from water, air-dried and stored for several days over Drierite. The salt dehydrates slowly if heated at 70 . 

An open-framework zinc phosphate synthesized under mild hydrothermal conditions possesses two interpenetrating helical channels.414 Piperazine phosphate yields a variety of open framework structures in reaction with zinc, including linear chain, layer, and three-dimensional systems.415... 

Piperazine Phosphate Sodium Propyl Hydroxy-benzoate Chlorphenesin Methsuximide Crotamiton... 

In a micronucleus study, administration of piperazine phosphate orally to mice at doses up to 5000 mg kg did not result in an increase in the level of micronuclei in bone marrow erythrocytes. 

Piperazine phosphate comes as a powder in 4 g sachets, together with standardised senna, which acts as a laxative to facilitate the expulsion of the paralysed worms. 

The required attributes listed above effectively limit the range of primary buffers available to between pH 3 and 10 (at 25 °C). Calcium hydroxide and potassium tetraoxalate tire excluded because the contribution of hydroxide or hydrogen ions to the ionic strength is significant. Also excluded are the nitrogen bases of the type BH+ (such as tris(hydroxymethyl)aminomethane and piperazine phosphate) and the zwitterionic buffers (e.g. HEPES and MOPS (10)). These do not comply because either the Bates-Gu enheim convention is not applicable, or the liquid junction potentials are high. This means the choice of primary standards is restricted to buffers derived from oxy-carbon, -phosphorus, -boron and mono, di- and tri-protic carboxylic acids. The uncertainties (11) associated with Harned cell measurements are calculated (1) to be 0.004 in pH at NMIs, with typical variation between batches of primary standard buffers of 0.003. 

Piperazine phosphate monohydrate, C4 Hi 2 N2 HPO4 H2 O, is a very good self buffer (pATa values of piperazine 5.333, 9.731 relevant pATa value of phosphoric acid 7.198 at 25° C) and it has been proposed for use as a pH standard. Measured pH values for an 0.02m solution from 0 to 50° C are given in Table 2.5. For an 0.05m solution the pH values should be increased by 0.009. 

Table 2.5 pH Values of 0.02 molal piperazine phosphate solutions ... 

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