## Abstract

TePEt_{3} reacts quantitatively with [M(Se_{4}) _{2}]^{2−} anions (M = Zn, Cd, Hg) in DMF. The ring-bound Se atoms are substituted by Te atoms in the MSe_{4} rings before the metal-bound Se atoms are. For n = 4, the reaction of n equiv of TePEt_{3} with 1 equiv of [M(Se_{4}) _{2}]^{2−} thus affords mixtures of [MTe_{n}Se_{8-n}]^{2−} anions, in which the Se atoms remain metal-bound. The pure isomer [PPh_{4}]_{2}[Hg(Te_{2}Se_{2}) _{2}] crystallizes in the tetragonal space group S_{4}^{2}-I4 with four formula units in a unit cell of dimensions a = 21.174(5) Å, c = 10.976(3) Å, and V = 4921(2) Å^{3} (T = 108 K). The values of the agreement indices R(F) and R_{w}(F^{2}) are 0.051 and 0.102, respectively. The [PPh_{4}]^{+} salts of [Hg(Se_{4}) _{2}]^{2−} and [Hg(TeSe_{3}) (Se_{4})]^{2−} cocrystallize in a 0.42:0.58 ratio in the monoclinic space group C_{2h}^{5}-P2_{1}/n with eight formula units in a unit cell of dimensions a = 22.911(3) Å, b = 20.161(4) Å, c = 23.685(2) Å,ß= 118.65(1) °, and V = 9601(2) Å^{3} (T = 108 K). The values of the final agreement indices are 0.078 and 0.153. The [PPh_{4}]^{+} salts of [Hg(Se_{4}) _{2}]^{2−}, [Hg(TeSe_{3}) (Se_{4})]^{2−}, [Hg(TeSe_{3}) _{2}]^{2−}, and [Hg(Te_{2}Se_{2}) (Se_{4})]^{2−} cocrystallize in a 0.05:0.39:0.43:0.13 ratio in the monoclinic space group C_{2h}^{5}−P2_{1}/c with eight formula units in a unit cell of dimensions a = 22.940(3) Å, b = 20.220(2) Å, c = 23.797(2) Å, ß = 118.50(1) °, and V = 9701(2) Å^{3} (T = 108 K). The values of the agreement indices are 0.059 and 0.127. From the ^{77}Se and ^{125}Te NMR chemical shifts, which are sufficiently sensitive, it was possible with one exception to distinguish every unique chalcogen atom in every [MTe_{n}Se_{8-n}]^{2−} anion from every other one; these resonances are assigned and discussed.

Original language | English (US) |
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Pages (from-to) | 1859-1867 |

Number of pages | 9 |

Journal | Inorganic Chemistry |

Volume | 34 |

Issue number | 7 |

DOIs | |

State | Published - Mar 1 1995 |

## ASJC Scopus subject areas

- Physical and Theoretical Chemistry
- Inorganic Chemistry