Two new silicate structures based on a rhodesite-type heteropolyhedral microporous framework.

摘要: Two new members of the mero-plesiotype rhodesite series [Sr(2)Na(2)(Si(8)O(19)).4H(2)O, abbreviated as TR09; SrNa(4)(Si(8)O(19)).4H(2)O, TR10] have been hydrothermally synthesized in Teflon-lined autoclaves at 503 K and structurally characterized using X-ray diffraction single-crystal data. The crystal structures were solved by direct methods refined to R = 0.021 [TR09; 3317 reflections with I(o) > 2sigma(I(o))] 0.033 [TR10; 5007 2sigma(I(o))]. Both are based on a rhodesite-type microporous heteropolyhedral framework, where two types channels within double silicate layer that alternates an ;octahedral' O sheet. large Sr(2+) cation constrains roughly ellipsoidal shape channels. H(2)O molecules located both sheets channels, they loosely hydrogen bonded. crystal-chemical features allow flexibility framework make it interesting for possible technological applications discussed.