CS273036B1 - Double cobalt-copper cyclo-tetraphosphates and method of their preparation - Google Patents

Abstract

The invention concerns new compounds of double cobalt-copper cyclo-tetraphosphates of the formula c-Co2-xCuxP4O12, where x is in a range of values approaching zero to values approaching two.They are prepared by crystallisation from the melt in a dry atmosphere at a temperature above 870 degrees C; the melt contains cobalt and copper cations in a reciprocal molar ratio of Co/Cu corresponding to the relationship (2-x)/x and further containing phosphate anions in a quantity corresponding to the ratio of P2O5/(Co+Cu) equalling 0.98 and 1.1 during their hardening.

Description

The invention relates to new compounds of type double cyclo tetrapolyphosphate ^cobalt-c ~ mě3natých formula ^Cu x ^Co 2.x ^P 4 ° i2 '3® ^{wherein x ranges} from values close to zero until the ee values close ee by two.

Of the compounds of the condensed phosphate type 8 Jednia divalent metal and 8 aolarium by immersion of phosphorus pentoxide ( ^p 2 ° s) to the corresponding metal equal to one, the yen known mostly are both cyclotetraphosphates (formulas x-Me ^ P ^ Oj ^) and higher linear phosphates (formula Men / 2 H 2 P _n 0 ^II _{3fj +} ^). ^{Thus toeu also} P ^{at pH ade} cobalt condensed phosphates, which exists as a cyclo-tetraphosphate dikobeltnatý (c-Co2P ^ Oj2) and higher linear phosphates kobeltneté ί ^ ° η / 2 ^Η 2 ^Ρ η ° 3η + ΐ) ^{1 EXAMPLE} ^ "padž cupric compounds when there is a higher linear phosphates W ^u * n / _n ^ £ ^Q 2n + l) e ¹ product cykllckýni tetrafoeforečnanovýai anlonty (c Cu ₂ P ^ 0 ^ _2). Double cyclotetraphosphates containing pairs of bivalent metal cations are gaining importance. These products have not been known so far and if the existence of condensed phosphates with pairs of these cations has been considered, then only the higher linear phosphates. However, these higher linear divalent metal phosphates, whether single ketone or double wolf catonts, find some properties that are suitable for their use. For they are substances of anorphine, non-crystalline, glassy character, which are fragile. The axes are relatively easily soluble, and some even tend to not get wet. Their thermal stability is provided with recrystallization temperatures (500 to 800 ° C).

Due to the existence of simple higher linear phosphates (and single cations) and simple cyclotrophosphates with the corresponding cation and, in particular, a comparison of their properties, it is expected that double compounds of the cyclo-tetraphosphate type will possess novel properties. It can be assumed that they will be far more appropriate than the higher linear phosphates for all contemplated uses of condensed phosphates.

SUMMARY OF THE INVENTION The present invention relates to cobalt-ammonium double cyclo-tetraphosphate phosphates as novel compounds of the formula ^e - ^c ® 2-x ^Cu x ^P 4 ° 12 * where x is in the range of from ee to zero up to two . The lower and upper limits for x result from the fact that the values zero to two cannot be used, since ee would no longer be a double product, namely pure, simple dicobaltous cyclo-tetraphosphate dicobaltate c-Co ₂ P ₄ Oj ₂ , respectively. dibasic orthophosphate c-CugP2O4. The cobalt-copper (II) -butyl cyclohexane phosphates are nodroflelic substances and their densities range from 3.4 to 3.6 g / cm ³ according to the Co / Cu coating. They have a crystal structure in a non-clinical set with a spatial group C 2 / c. The lattice parameters ae according to the Co / Cu ratio range from 1.1799 to 1.2546 nn for a, 0.8092 to 0.8304 nn for b, 0.9565 to 0.9887 nn for c, 118.50 ° to 118.70 ° for the beta angle, and the volume of the elementary cell ee moves in range 0.8441 to 0.8523 nm ³ . The cobalt-ammonium double cyclohexanephosphates are chemically and thermally very stable substances, which are insoluble in water, organic solvents and dilute mineral acids, only slowly dissolve in caustic solutions. It melts at high temperatures according to the Co / Cu ratio in the range of 870 to 1060 ° C. In a completely dry atmosphere or in vacuum, it melts congruently, in an atmosphere containing at least traces of water vapor melts non-congruantly.

SUMMARY OF THE INVENTION It has been found that the cobalt-copper (II) double cyclo-tetraphosphates are prepared by causing a melt having a temperature above 870 ° C, preferably above 1060 ° C, containing cobalt and copper cations in a Co / Cu solar ratio corresponding to (2-x) / x and the data comprise phosphate anonites in an amount corresponding to a molar ratio of P ₂ O _s / (Co-Cu) of 0.98 to 1.1, preferably equal to 1 to 1.005, 5 ° C to give the product as microcrystals. The melt temperature should be selected above the melting point or the freezing point of the products, which ranges from 870 to 1060 ° C, depending on the Co / Cu coating. Mutual ratio of cobalt and green catlons in melted ae voli poX

CS 273 036 Bl

While the requirement for their content in the product is present, the amount of the variable cations may vary within a range. from values approaching zero to. ee two values. The content of phosphate anions in the melt had to correspond to a molar ratio of P ₂ O ₅ / (Co + Cu) equal to one, or to densities differing only from alo to one, corresponding to the total product c-Co _{2-J {} Cu _x P ₄ Oj ₂ otherwise, by-products would be formed in the form of other types of condensed phosphates and would significantly decrease according to the main product. Crystallization of the product by solidification from melt cooling should be conducted in a completely dry atmosphere (or under vacuum) since the presence of even trace amounts of water feathers would again lead to condensation of phosphates and other anions and not 8 anions of cyclotetraphosphate. In this case, it is advantageous to conduct the cooling of the melt at a rate of less than 5 [deg.] C./min, since the possibility of formation of other undesirable condensation products is thereby reduced. If desired, the products according to the invention can still be purified with hydrochloric, sulfuric, nitric or phosphoric acid, since the double cyclotrophosphates resist the leaches, while the other products which have formed are dissolved. The preferred acid concentration for the leach is 0.05 to 10 wt. % of the by-product leaching is sufficiently effective while the risk of attack of the main product is negligible.

The advantages of the invention are that it indicates the existence of new compounds which have not been known so far. These compounds accumulate advantageous physicochemical and application properties having simple divalent metal cyclotetrophosphates.

Example 1

The melt prepared by melting 100 g of higher linear cobalt phosphates and 102.1 g of higher linear copper phosphates at 1080 ° C was cooled in a dry atmosphere at a rate of 6 ° C / min. 202.1 g of a microcrystalline product was obtained, containing 95.8 wt. % C-CoCuP ₄ O | £, blue-violet microcrystals They are in a monoclinic system, the spatial group C 2 / c, whose lattice parameters are a 1,2027 nm, b 0,8202 nm, c ⁿ 0.9737 nm, beta 118.50 and a unit cell volume of 0.8461 nm. Their density is 3.45 g / cm and the melting point is 911 ° C.

Example 2

The melt prepared by melting 150 g of higher linear cobalt phosphates and 51.05 g of higher linear copper phosphates at 1100 ° C was cooled under vacuum at a rate of 20 ° C / nln. 201.0 g of the cryocrystalline product containing 97.9 wt. c-Coi gCu _{0 5} ^ρ 4θΐ2 · Blue-violet microcrystals are in a monoclinic system, spatial group C 2 / c, whose lattice parameters are a ·> 1.1868 nm, b 0.8258 nm, c = 0.9841 nm, peak at 118.56 ° and elemental cell volume 0.8462 nm. Their density is 3.42 g / cm and the melting point is 956 ° C.

Example 3

The melt prepared by melting 50 g of higher linear cobalt phosphates and 153.2 g of higher linear cupric phosphates at 950 ° C was cooled in a dry atmosphere at a rate of 2 ° c / mln. 203.2 g of a microcrystalline product was obtained, which contained 94.6 wt. % Cyclo-double tetrapolyphosphate cobalt-měcSnatého formula ^{C "Ce} 0.5 l ^Cu, 5 ^P 4 ° l2 · Blue-violet microcrystals are monoclinic, space group C2 / c, the lattice parameters and jeou» 1.2338 nm, b 0.8138 nm, c 0.9641 nm, beta 118.62 and the cell volume is 0.8504 per. Their density is 3.52 g / cm and the melting point is 885 ° C.

Claims (2)

1. Double cobalt tetra-phosphate double cyclo-tetraphosphates of the formula ^cc 2 -X ^Cu X ^P 4 ° 12 · **** · * ranges from near to zero up to and near two. 2. A process for the preparation of double cyclotrophosphates, characterized in that the melt has a temperature above 870 [deg.] C. and preferably above 1,060 [deg.] C., containing cobalt and cupric cations in a Co / Cu molar ratio corresponding to (2-x) / x and containing phosphate anions in an amount corresponding to a molar ratio of P ₂ O _g / (Co + Cu) of 0.98 to 1.1, preferably of 1 to 1.005, is allowed to solidify in a completely dry atmosphere by cooling, preferably at a rate of less than 6 ° C The cobalt-copper (III) -cyclo-tetraphosphates of microcrystalline character are then optionally treated by leaching with hydrochloric, sulfuric, nitric or phosphoric acid, preferably a concentration of 0.05 to 10% by weight.