Two compounds containing unbranched Se chains have resulted from the dissolution of Cs3TaSe4 in acetonitrile in the presence of 18-crown-6 and bis(triphenylphosphine)nitrogen(1+) chloride. These new compounds have been characterized by X-ray structure determinations. [Cs(18-crown-6)]2[Se5].CH3CN crystallizes in the monoclinic space group Ch2h2-P21/m, with a = 10.299 (6) Å, b = 15.097 (9) Å, c = 13.768 (8) Å, β = 100.05 (2)°, V = 2108 Å3, and Z = 2. [PPN]2[Se4].4CH3CN crystallizes in the monoclinic space group C52h-P21/c, with a = 10.792 (3) Å, b = 12.653 (4) Å, c = 26.209 (14) Å, β = 90.57 (3)°, V = 3579 Å3, and Z = 2. The nonplanar Se52- chain has a cis configuration and crystallographic symmetry m, while the Se42- chain is planar and trans with a crystallographically imposed center of symmetry. A comparison of metrical data for these isolated ions with those for their free and liganded counterparts is provided.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry