Crystals of the acidic diphosphate K2Cu(H2P2O7)2·2 H2O, dipotassium copper bis(dihydrogendiphosphate) dihydrate, obtained via two different syntheses, revealed by means of single-crystal X-ray diffraction to be polymorph within triclinic P? (a = 6.8560(4), b = 7.3140(3), c = 7.5570(4) Å; ? = 81.028(4)°, ? = 72.327(5)°, ? = 83.697(5)°, V = 355.86(3)Å3) and orthorhombic Pnma (a = 9.8990(6), b = 10.7810(7), c = 13.4010(7) Å, ? = ? = ? = 90°, V = 1430.17(15) Å3) space groups. Both phases were analyzed by FT-IR and micro-Raman vibrational spectroscopy and interpreted using factor group analysis. No coincidences of majority of the Raman and infrared spectral bands of K2Cu(H2P2O7)2·2 H2O confirmed the centrosymmetric structure of these two materials. The vibrational spectra point to a bent POP bridge angle.
Structure and Vibrational Spectra of a New Acidic Diphosphate K2Cu(H2P2O7)2·2H2O.
2013
Abstract
Crystals of the acidic diphosphate K2Cu(H2P2O7)2·2 H2O, dipotassium copper bis(dihydrogendiphosphate) dihydrate, obtained via two different syntheses, revealed by means of single-crystal X-ray diffraction to be polymorph within triclinic P? (a = 6.8560(4), b = 7.3140(3), c = 7.5570(4) Å; ? = 81.028(4)°, ? = 72.327(5)°, ? = 83.697(5)°, V = 355.86(3)Å3) and orthorhombic Pnma (a = 9.8990(6), b = 10.7810(7), c = 13.4010(7) Å, ? = ? = ? = 90°, V = 1430.17(15) Å3) space groups. Both phases were analyzed by FT-IR and micro-Raman vibrational spectroscopy and interpreted using factor group analysis. No coincidences of majority of the Raman and infrared spectral bands of K2Cu(H2P2O7)2·2 H2O confirmed the centrosymmetric structure of these two materials. The vibrational spectra point to a bent POP bridge angle.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
