Ayaaz Mehdi Pirani

[2,2,2-Crypt-Na]2[Cr2(CO)10]: a Chromium(–1) Carbonyl Structure with a Very Weakly Coordinating Cation

The title compound, bis[(1,10-diaza-4,7,13,16,21,24-hexaoxabicyclo[8.8.8]hexacosane)sodium(+)] decacarbonyldichromate(Cr—Cr)(2-), [Na(C18H36N2O6)]2[Cr2(CO)10], has been prepared by the reduction of [Cr(CO)6] with Na2Tl in dimethylformamide followed by the addition of the macrobicyclic ligand, 2,2,2-crypt in ethylenediamine (en) solvent. The geometric parameters observed for the anion in the title salf differ significantly from those reported previously for the DME solvated (DME = 1,2-dimethoxyethane) K+ and [PPN]+ {[PPN]+ = bis[bis(triphenylphospine)iminium]} salts, reflecting the more weakly coordinating nature of the [2,2,2-crypt-Na]+ cation.

(K+)2(18-crown-6-K+)2[Sn2Se6]4−.4en: an [Sn2Se6]4− Anion with a Short Sn

The title compound, dipotassium(+) bis[(1,4,7,10,13,16-hexaoxacyclooctadecane)potassium(+)] hexaselenodistannate(4−) tetrakis(ethylenediamine) solvate, K2[K(C12H24O6)]2[Sn2Se6].4C2H8N2, (1), has been prepared by the extraction of the alloy KSn0.67Se1.93 in en (en = ethylenediamine) in the presence of 18-crown-6 followed by addition of tetrahydrofuran. The geometric parameters observed for the Sn2Se64− anion in (1) are significantly different from those previously reported in the (enH+)2(2,2,2-crypt-K+)2 (2,2,2-crypt is 1,10-diazabicyclo- 4,7,13,16,21,24-hexaoxa[8.8.8]hexacosane), K+(NMe3+)3 and M+ (M = Na, K, Rb, Cs) salts.