反应详情

Thirty grams of ZnSO4 ·7H2O was dissolved in 200 ml. deionized water at room temperature. Thereafter, 20 g. picolinic acid (Sigma Chemical, St. Louis, MO) was added to the solution and the solution was stirred continuously. Within 3-5 minutes a precipitate began to form. After 30 minutes the stirring was discontinued and the mixture was left standing at room temperature until the precipitate had settled to the bottom. The supernatant was removed by aspiration and the precipitate was suspended in enough deionized water to yield 200 ml. This suspension was then heated in a beaker with continuous stirring until the precipitate had completely dissolved after which the beaker was placed in an ice bath and stored overnight in a cold room (4°). The following morning the supernatant was aspirated from the crystals and the crystals were freeze dried. Assay of the crystals proved that the complex contained 2 moles of picolinic acid and 1 mole of zinc [zinc dipicolinate, Zn(PA)2 ].

1. customat room temperature
2. customto form
3. waitAfter 30 minutes the stirring was discontinued
4. waitthe mixture was left
5. customstanding at room temperature until the precipitate
6. customThe supernatant was removed by aspiration
7. customto yield 200 ml
8. temperatureThis suspension was then heated in a beaker
9. stirringwith continuous stirring until the precipitate
10. dissolutionhad completely dissolved after which the beaker
11. customwas placed in an ice bath
12. waitstored overnight in a cold room (4°)
13. customdried