Hydrothermal synthesis and characterization of two new arsenic–vanadate compounds with the same cluster anion [As₈V₁₄O₄₂(H₂O)]⁴⁻

Abstract

Two new arsenic-vanadate compounds [Co(C 4 H 13 N 3 ) 2 ] 2 [As 8 V 14 O 42 (H 2 O)] Á 3.5H 2 O (1) and (C 2 N 2 H 9 ) 2 (C 2 N 2 H 10 )[As 8 V 14 O 42 (H 2 O)] Á 2.33H 2 O (2) have been hydrothermally synthesized and characterized by X-ray single crystal diffraction, IR spectra and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic space group P 2 (1)/c, a ¼ 24.649(9) Å , b ¼ 13.364(5) Å , c ¼ 22.463(8) Å , ¼ 104.008(5) , V ¼ 7180(5) Å 3 , Z ¼ 4, R 1 ¼ 0.0787, and wR 2 ¼ 0.1859. Compound 2 crystallizes in rhombohedral system with space group R3c, a ¼ b ¼ c ¼ 22.2405(5) Å , ¼ ¼ ¼ 110.4030(10) , V ¼ 8163.4(3) Å 3 , Z ¼ 6, R 1 ¼ 0.0341 and wR 2 ¼ 0.0941. The structural analyses show that both compounds have the same discrete cluster anion [As 8 V 14 O 42 (H 2 O)] 4À . Moreover, in 1, the polyanions are connected through van der Waals forces to generate soft channels that are filled by [Co(C 4 H 13 N 3 ) 2 ] 2þ cations and water. In 2, water and organic molecules link cluster anions to create the supramolecular assembly through hydrogen bonding.

In situ ligand exchange-mediated 0D/1D transformation of a polyoxovanadate

“…Si, Ge, As, or Sb. 1 Charge compensation of the negatively charged POV clusters is realized by ammonium, [2][3][4] alkali metals cations, [5][6][7][8] protonated amine molecules [9][10][11][12] or transition metal amine complexes. [13][14][15] There are also reports that bond formation between the POV cores and cations [16][17][18] leads to charge-neutral complexes.…”