Darstellung und Struktur des Polyvanadato-periodates Na₆[H₂V₂I₂O₁₆]·10H₂O / Preparation and Crystal Structure of the Heteropoly Periodate Na₆[H₂V₂I₂O₁₆]·10H₂O

Abstract

<jats:title>Abstract</jats:title><jats:p> The structure of the heteropoly periodate ion [H<jats:sub>2</jats:sub>V<jats:sub>2</jats:sub>I<jats:sub>2</jats:sub>O<jats:sub>16</jats:sub>]<jats:sup>6-</jats:sup> has been determined in its Na salt at -150 °C by single crystal X-ray diffraction with 1909 reflections and refined to F = 0.022 (R′= 0.028). Na<jats:sub>6</jats:sub>[H<jats:sub>2</jats:sub>V<jats:sub>2</jats:sub>I<jats:sub>2</jats:sub>O<jats:sub>16</jats:sub>]·10H<jats:sub>2</jats:sub>O crystallizes in the triclinic space group P1 with a = 11.407(5), b = 8.865(3), c = 6.105(3) Å, α = 82.07(3)°, β = 84.24(4)° γ = 70.23(3)°, V = 574.5 Å<jats:sup>3</jats:sup> , Z = 1. The [H<jats:sub>2</jats:sub>V<jats:sub>2</jats:sub>I<jats:sub>2</jats:sub>O<jats:sub>16</jats:sub>]<jats:sup>6-</jats:sup> anion consists of edge and corner sharing IO<jats:sub>6</jats:sub> octahedra and VO<jats:sub>5</jats:sub> square pyramids. The vibrational spectra clearly indicate the presence of VO(terminal)<jats:sub>2</jats:sub> groups.</jats:p>

Structure of hexasodium dihydrogendivanadodiperiodate decahydrate

“…All ten H atoms of five water molecules were found at distances of Note added in proof." The authors noticed lately the study of the same structure at 123 K (Mattes & Richter, 1982). Changes of the corresponding distances are found to be significant.…”

Synthesis, Spectroscopic and Structural Studies on Vanadium(V) Periodates

“…The reaction of V 2 O 5 with aqueous NaHCO 3 , followed by the addition of sufficient H 5 IO 6 to take the pH to approximately 7.5, gave a yellow solution from which pale yellow Na 6 [V 2 I 2 H 2 O 16 ] · 10H 2 O separated on standing 13. The same product was also obtained by starting with NaVO 3 and H 5 IO 6 and following a slightly modified literature procedure 14.…”

“…The powder X‐ray diffraction patterns for the products obtained by the two methods were in excellent agreement and also agreed well with the pattern simulated from the single‐crystal X‐ray diffraction data 14. The structure of this discrete complex anion (Figure 1) is based upon IO 5 (OH) octahedra [I–O 1.820(2)–1.961(3) Å] sharing vertices with two essentially square‐pyramidal VO 5 groups [V–O 1.628(3)–2.109(2) Å] and a very long bond to a sixth oxygen [V–O 2.544(2) Å] 13,14. The IR spectrum shows bands at 3400 ν(OH), 1635 δ(HOH), 1174 δ(IOH), 939, 845 ν(VO), 756, 684 ν(IO) cm –1 and lower frequency bands due to ν(V–O–I).…”

“…Method 1: Using the method of Mattes et al,13 a slurry of NaHCO 3 (7.6 g, 90 mmol) in water (125 mL) and V 2 O 5 (2.75 g, 15 mmol) was heated until a clear pale yellow solution was formed. The solution was cooled to room temperature and filtered.…”

“…Recently, there has been interest in the SHG properties of vanadium iodates, including some very strong responses from Na[VO 2 (IO 3 ) 2 (H 2 O)] 11,12. In group 5, there is a single example of a vanadium periodate complex, Na 6 [V 2 I 2 H 2 O 16 ] · 10H 2 O, whose structure has been independently reported twice,13,14 which contains edge‐sharing IO 5 OH and VO 5 groups, although other data on this complex are limited. The only other report is on compounds with a 2:1 V/I ratio dating from 1923 15.…”