Self-assembly of [Cu(CN)4]3− ions with cationic {Me3Sn}+ or {Me2Sn(CH2)3SnMe2}2+ fragments in the presence of a nBu4N+ template

As described earlier, solutions of nBu4NCl and K3[Cu(CN)4] react with Et3SnCl to zeolite-like [(Bu4N)(Et3Sn)2Cu(CN)4] (1), but with Me3SnCl exclusively to [(Bu4N)(Me3Sn)Cu2(CN)4] (2), the crystal structure of which is reported here for the first time. The nBu4N+ guest ions of 2 are accommodated between planar, negatively charged layers, wherein three-coordinated Cu(I) ions are interlinked by CN and CN·SnMe3·NC bridges (2:1). The slightly modified new homologue of 2: [(nBu4N){Me2Sn(CH2)3SnMe2}0.5Cu2(CN)4] (3), displays an almost identical powder X-ray diffractogram as 2 and, moreover, surprisingly similar solid-state NMR spectra for the nuclei 13C, 15N and 119Sn. A three-dimensional host framework is postulated to encapsulate the nBu4N+ guest of 3, the Sn atoms of adjacent layers being therein tied pair-wise together by trimethylene tethers, (CH2)3. For further comparison, the solid-state NMR data of the new coordination polymer [{Me2Sn(CH2)3SnMe2}0.5Au(CN)2] (5) are also presented.