SYNTHESES AND CRYSTAL STRUCTURES OF POTASSIUM SALTS OF 3-NITROPHENOL AND 4-NITROPHENOL
The potassium salts of 3-nitrophenol and 4-nitrophenol were synthesized. Volumetric methods were used to add aqueous potassium hydroxide to ethanolic phenol in a 1:1 stoichiometric ratio. The 3-nitrophenol solution immediately produced a red precipitate. The 4-nitrophenol solution immediately produced a bright yellow precipitate. Gravity filtration with deionized water was employed to separate both products from impurities. Slow evaporation resulted in a precipitate of thin, dark orange crystal aggregates of 3-nitrophenolate and large yellow-green rhomboid-esque crystals of 4-nitrophenolate. The crystals were analyzed by x-ray diffraction. The unit cell dimensions (a = 3.90094(7) Å, b = 43.8508(8) Å, c = 10.8990(2) Å, a = 90°, b = 90.738(2)°, g = 90°) of the crystal of the 1:2 complex of potassium 3-nitrophenolate and 3-nitrophenol and its crystal structure were determined. The potassium cation is coordinated by oxygen atoms from both phenols and nitro groups. The phenolate oxygen receives hydrogen bonds from adjacent phenols. It is interesting that the crystal structure displayed an absence of water in the unit cell. The unit cell dimensions (a = 10.4947(4) Å, b = 7.2933(2) Å, c = 11.2310(4) Å, a = 90°, b = 117.650(5)°, g = 90°) of potassium 4-nitrophenolate monohydrate and its crystal structure were determined. The potassium cation is coordinated by water, nitro, and phenolate oxygen atoms. The phenolate oxygen is accepting hydrogen bonds from adjacent waters.
We thank Dr. John Bacsa, Emory X-ray Crystallography Facility for the X-ray structural analysis and acknowledge the use of the Rigaku Synery diffractometer supported by the National Science Foundation under grant CHE-1626172. We also acknowledge Berry College and the Richards Undergraduate Research Grant.
Kahn, Paula A. and Martin, Kenneth L.
"SYNTHESES AND CRYSTAL STRUCTURES OF POTASSIUM SALTS OF 3-NITROPHENOL AND 4-NITROPHENOL,"
Georgia Journal of Science, Vol. 76, No. 1, Article 129.
Available at: https://digitalcommons.gaacademy.org/gjs/vol76/iss1/129