Trimetaphosphate

The hexahydrate is formed by the addition of anhydrous STP to water or by the hydrolysis of sodium trimetaphosphate [7785-84-4] (STMP), (NaP02)3, in alkaline media. The hexahydrate is stable at room temperature but undergoes rapid hydrolytic degradation to pyro- and orthophosphate upon drying. 

Sodium tripolyphosphate is produced by calcination of an intimate mixture of orthophosphate salts containing the correct overall Na/P mole ratio of 1.67. The proportions of the two anhydrous STP phases are controlled by the calcination conditions. Commercial STP typically contain a few percent of tetrasodium pyrophosphate and some trimetaphosphate. A small amount of unconverted orthophosphates and long-chain polyphosphates also may be present. 

Other Tripolyphosphates. Potassium tripolyphosphate [24315-83-1] (KTP), K P O q, has a high aqueous solubihty (near 180 g/100 g) and has been used in place of STP for Hquid detergents. The potassium salt, however, is more expensive than STP. Sodium potassium tripolyphosphate (SKTP), Na K P O Q, is prepared by calcination of a feed Hquor having the proper Na20/K20ratio or by reaction of sodium trimetaphosphate with KOH. For some detergent or food appHcations, SKTP may provide the optimum compromise between solubihty and cost. 

The only tme metaphosphate (ring stmcture) of significant commercial interest is sodium trimetaphosphate (STMP), Na P O. Because of the strain inherent in the small ring stmcture, STMP is more reactive toward nucleophiles than chain phosphates. In the presence of NaOH, for example, STMP forms sodium tripolyphosphate. 

Although reasonably stable at room temperature under neutral conditions, tri- and tetrametaphosphate ions readily hydrolyze in strongly acidic or basic solution via polyphosphate intermediates. The hydrolysis is first-order under constant pH. Small cycHc phosphates, in particular trimetaphosphate, undergo hydrolysis via nucleophilic attack by hydroxide ion to yield tripolyphosphate. The ring strain also makes these stmctures susceptible to nucleophilic ring opening by other nucleophiles. 

Cross-bonded starches can also be manufactured by reaction with trimetaphosphates (115), but these require more vigorous conditions than phosphoms oxychloride. Typically, a starch slurry and 2% trimetaphosphate salt react at pH 10—11 and 50°C for 1 h. 

Sodium trimetaphosphate was used as an eluting agent for the removal of heavy metals such as Pb, Cd, Co, Cu, Fe, Ni, Zn and Cr from aqueous solutions. Distribution coefficients of these elements have been determined regarding five different concentrations of sodium trimeta phosphate (3T0 M 5T0 M 0.01 M 0.05 M 0.1 M) on this resin. By considering these distribution coefficients, the separation of heavy metals has been performed using a concentration gradient of 3T0 - 5T0 M sodium trimetaphosphate. Qualitative and quantitative determinations were realized by ICP-AES. 

It has been seen that this resin has also some important advantages over the other resins in the literature like high total ion exchange capacity, easy synthesis, lower cost, simple regeneration. Furthermore, very good sepai ations were obtained using a concentration gradient of elution. In these elutions, very low concentrations of sodium trimetaphosphate were used. As a result, the resin synthesized can be used as an adsorbent for the effective removal of Pb, Cd, Co, Cu, Fe, Ni, Zn and Cr from aqueous solutions. 

Chemical Designations - Synonyms Sodium phosphate is generic term and includes the following (1) monosodium phosphate (MSP sodium phospWe, monobasic), (2) disodium phosphate (DSP sodium phosphate dibasic), (3) trisodium phosphate (TSP sodium phosphate, tribasic), (4) sodium acid pyrophosphate (ASPP SAPP disodium pyrophosphate (TSPP), (6) sodium metaphosphate (insoluble sodium metaphosphate), (7) sodium trimetaphosphate, and (9) sodium tripolyphosphate (STPP TPP) Chemical Formula (1) NaHjPO (2) Na HPO (3) NajPO (4) Na H P O, (5) Na P O, (6) (NaPOj) (7) (NaP03)3 (8) (NaP03) NaO (9) Na,P30,o. 

The complex preparative interrelationships occurring in the sodium polyphosphate system are summarized in Fig. 12.21 (p. 531). Thus anhydrous NaH2p04, when heated to 170" under conditions which allow the escap>e of water vapour, forms the diphosphate Na2H2p207, and further dehydration at 250" yields either Maddrell s salt (closed system) or the cyclic trimetaphosphate (water vapour pressure kept low). Maddrell s salt converts from the low-temperature to the high-lemperaturc form above 300", and above 400" reverts to the cyclic... 

NaAs03 has an infinite polymeric chain anion similar to that in diopside (pp. 349, 529) but with a trimeric repeat unit LiAs03 is similar but with a dimeric repeat unit whereas /6-KASO3 appears to have a cyclic trimeric anion As309 which resembles the cyc/o-trimetaphosphates (p. 530). There is thus a certain structural similarity between arsenates and phosphates, though arsenic acid and the arsenates show less tendency to catenation (p. 526). The tetrahedral As 04) group also resembles PO4) in forming the central unit in several heteropoly acid anions (p. 1014). 

Alkali metal trimetaphosphates react with primary amines in water at a pH value between 7 and 10, and at a temperature between 40 and 90°C, to yield surface-active alkylamidotriphosphates [64-66] see Eq. (20) ... 

It is also possible to use salts of polyphosphoric acids, e.g., trimetaphosphate, as the phosphorylating agent in reaction with alkylamines, as is shown in Eq. (75). 

Physical properties and loading capacity of starch-based microparticles crosslinked with trisodium trimetaphosphate. Journal of Food Engineering, Vol. 92, 3, 0une 2009), pp. (255-260), ISSN 0260-8774... 

Any discussion of the prebiotic phosphorylation of nucleosides must take into account the probably neutral or alkaline conditions in a prebiotic environment. Some model phosphorylating systems have been studied, for example, the synthesis of /S-o-ribofuranose 1-phosphate from ribose and inorganic phosphate in the presence of cyanogen. Sodium trimetaphosphate will phosphorylate cw-glycols in good yield under alkaline... 

For the preparation of monofluorophosphates there are quite a lot of methods found in literature. The alkali salts are obtained by shortly melting poly- or trimetaphosphate with alkali fluoride (29,30) - the application of graphite vessels yielding particulary pure products (31) ... 

Kutun, S. and Akseli, A., New elution agent, sodium trimetaphosphate, for the separation and determination of rare earths by anion-exchange chromatography, /. Chromatogr. A, 847, 261, 1999. 

Fragmentation of 143 is not limited to aqueous media. Reaction of threo-745 with cyclohexylamine, triethylamine, or 2,6-lutidine in acetonitrile also leads to (Z)-144 while the phosphorus appears in various polyphosphates, in the trimetaphosphate trianion (after 110 °C/5 h, before work-up), and in phosphoramidates 95). 

Esters of monomeric metaphosphoric acid like 147 are just as unisolable as metaphos-phoric acid itself or its anion. All the metaphosphoric esters described in the previous literature1011 are probably actually mixtures of oligomeric metaphosphoric esters, or well defined compounds such as cyclic trimetaphosphate. 

On use of N,N -dicyclohexylcarbodiimide instead of sulfonyl chlorides as condensation reagent in oligonucleotide synthesis, then the pyro-, tri- and tetraphosphate stages are again involved 124). The metaphosphate 183 a is found in small amounts by 3iP-NMR spectroscopy, but again no cyclic trimetaphosphate 184 can be detected, which would also be a possible phosphorylation reagent. 

Various polyphosphates are effective sequestering agents under appropriate conditions. The best known of these is sodium hexametaphosphate (10.14), the cyclic hexamer of sodium orthophosphate. Further examples are the cyclic trimer sodium trimetaphosphate (10.15), as well as the dimeric pyrophosphate (10.16), the trimeric tripolyphosphate (10.17) and other linear polyphosphates (10.18). All of these polyanions function by withdrawing the troublesome metal cation into an innocuous and water-soluble complex anion by a process of ion exchange as shown in Scheme 10.7 for sodium hexametaphosphate. Hence these compounds are sometimes referred to as ion-exchange agents. 

The synthesis of pentose-2,4-diphosphate referred to above gave the best yields of a ribose derivative. Thus, the search for an effective synthesis leading to necessary starting materials such as glycol aldehyde phosphate (GAP) was important Krishnamurthy et al. (1999, 2000) reported new synthetic routes to GAP glycol aldehyde is allowed to react with amidotriphosphate (AmTP) in dilute aqueous solution. The triphosphate derivative is formed from trimetaphosphate and NH4OH. 

Fig. 4.13 The phosphorylation of glycerinic acid by the trimetaphosphate ion to give 3- or 2-phosphoglycerinic add. After Kolb and Orgel (1996)...

Critics of such experiments may And the concentration of reducing gases too high. It is, however, possible that there were localized areas on Earth where conditions were more strongly reducing for short periods (e.g., after volcanic eruptions). In the search for potential prebiotic syntheses of condensed phosphates, Keefe and Miller (1996) allowed a series of condensation agents to act on o-phosphate or tripolyphosphate, and determined the yields of diphosphate and trimetaphosphate obtained. 

The phosphorylation of adenosine with trimetaphosphate under mild conditions (pH about 7, 413 K) was described by Yamagata (1995). The main product was... 

Reimann and Zubay found that 5 -AMP is selectively converted to adenosine-5 -polyphosphate when a solution of nucleotides, trimetaphosphate and MgCh is evaporated down. These are the same conditions under which 2 (3 )-AMP is converted to 2, 3 -cyclic AMP. 

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