## Abstract

The four tetrachalcogenometalates K_{3}NbS_{4}, K_{3}NbSe_{4}, K_{3}TaS_{4}, and K_{3}TaSe_{4}have been obtained by direct reaction among the elements at 850 °C. The structures of K_{3}NbS_{4}and K_{3}NbSe_{4}have been determined by single-crystal X-ray diffraction methods. K_{3}TaS_{4}and K_{3}TaSe_{4}are isostructural with K_{3}NbS_{4}and K_{3}NbSe_{4}, as determined from X-ray Guinier photographs. All of them crystallize with four formula units in space group D^{16} _{2h}-Pnma of the orthorhombic system in cells of dimensions a = 9.214 (8), b = 10.484 (6), and c = 9.319 (7) Å for K_{3}NbS_{4}, a = 9.599 (2), b = 11.042 (3), and c = 9.660 (2) Å for K_{3}NbSe_{4}, a = 9.283 (2), b = 10.806 (3), and c = 9.387 (2) Å for K_{3}TaS_{4},and a = 9.682 (3), b = 11.276 (4), and c = 9.712 (3) Å for K_{3}TaSe_{4}. The final refinements of 43 variables lead to R and R_{w}values of 0.106 and 0.115 for K_{3}NbS_{4}and 0.069 and 0.083 for K_{3}NbSe_{4}. These structures are of the K_{3}VS_{4}type and contain discrete K_{+}and tetrahedral MQ_{4} ^{3-}ions. In K_{3}NbS_{4}the Nb-S distances range from 2.241 (8) to 2.258 (8) Å and the S-Nb-S angles range from 108.3 (2) to 111.6 (3)°. In K_{3}NbSe_{4}the Nb-Se distances range from 2.387 (1) to 2.403 (1) Å and Se-Nb-Se angles range from 108.49 (3) to 111.68 (5)°.

Original language | English (US) |
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Pages (from-to) | 1503-1505 |

Number of pages | 3 |

Journal | Inorganic Chemistry |

Volume | 29 |

Issue number | 8 |

DOIs | |

State | Published - Jan 1 1990 |

## ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Inorganic Chemistry