摘要
The crystal structure of Rb <sub>2</sub> V <sub>3</sub> P <sub>4</sub> O <sub>17</sub> has been determined from single‐crystal X‐ray diffraction data. Rb <sub>2</sub> V <sub>3</sub> P <sub>4</sub> O <sub>17</sub> crystallizes in the orthorhombic space group Pnma (No. 62) with a = 17.502(7), b = 7.292(2), c = 11.399(6) Å <sup>3</sup> , V = 1455(1) Å <sup>3</sup> , Z=4, R=0.0295, R <sub>W</sub> = 0.0320 for 1129 unique reflections with I > 2.5 σ(I). The structure contains intersecting tunnels where the Rb <sup>+</sup> cations are located. The framework can be described as consisting of V <sup>2</sup> O <sub>10</sub> units formed from one VO <sub>5</sub> square pyramid and one VO <sub>6</sub> octahedron sharing a corner, and infinite chains of corner‐shared VO <sub>6</sub> octahedra, which are linked in three dimensions by pyrophosphate groups. The structural formula is Rb <sub>2</sub> (VO) <sub>3</sub> (P <sub>2</sub> O <sub>7</sub> ) <sub>2</sub> . A single‐phase product can be obtained by heating appropriate amounts of Rb <sub>4</sub> V <sub>2</sub> O <sub>7</sub> , VO <sub>2</sub> , V, and P <sub>2</sub> O <sub>5</sub> in an evacuated fused silica tube at 950°C. Powder magnetic susceptibility data confirm the presence of V <sup>4+</sup> (d <sup>1</sup> ) ions without magnetic ordering down to 3 K. Copyright © 1990 The Chemical Society Located in Taipei & Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim, Germany