Synthesis and structure of [K(+)-(2,2)diaza-[18]-crown-6][K3Ge9]-2ethylenediamine: stabilization of the two-dimensional layer (2)(infinity)[K3Ge9(1-)]

C Downie; J G Mao; A M Guloy

doi:10.1021/ic001107q

Synthesis and structure of [K(+)-(2,2)diaza-[18]-crown-6][K3Ge9]-2ethylenediamine: stabilization of the two-dimensional layer (2)(infinity)[K3Ge9(1-)]

Inorg Chem. 2001 Aug 27;40(18):4721-5. doi: 10.1021/ic001107q.

Authors

C Downie¹, J G Mao, A M Guloy

Affiliation

¹ Department of Chemistry, University of Houston, Houston, Texas 77204-5641, USA.

PMID: 11511221
DOI: 10.1021/ic001107q

Abstract

Large bright-red, transparent crystalline plates of [K-(2,2)diaza-[18]-crown-6]K3Ge9-2en are obtained, in high-yield, from a reaction of (2,2)diaza-[18]-crown-6 in toluene with a solution of K4Ge9/potassium metal (K) in ethylenediamine (en). The compound crystallizes in the monoclinic space group P2(1)/m (a = 10.740(1) A, b = 15.812(1) A, c = 12.326(1) A, beta = 114.74 degrees; Z = 2). The crystal structure of [K-(2,2)diaza-[18]-crown-6]K3Ge9-2en features two-dimensional [K3Ge9] layers formed by uncomplexed K(+) cations and Ge94(-) anions. The "not-so-bare" cluster compound features a unique Ge94(-) cluster that exhibits a slightly distorted C(2v) geometry that is closer to D(3h) than the expected C(4v). Use of noncryptand sequestering agents in the isolation of Ge cluster anions from en solutions opens new avenues in understanding important cation-anion interactions in the stability and reactivity of Zintl ions, as well as a viable route to isolating Zintl anions with higher charges per atom.