| 摘要 |
<p>Hydrophobic microporous crystalline tectosilicate material (I) of regular geometry comprises Al-free sites in a siliceous lattice that contain 1-4 moieties of formula Si(OR) where R is a substit. that is a weaker pt. electric source than Al or OH. - Pref. tectosilicates are (I) with R = 1-4C alkyl or acyl, pref. Si(R1)nXp (where R1 = 1-4C alkyl or acyl, cycloalkyl, aryl, aralkyl or mixts.; X = halogen or loner alkoxy esp. Cl; n = 0-3 esp. 1-2; p = esp. 1-2; p = 3-n). The Al-free sites may be prepd. by: (a) removal of Al from an aluminous tectosilicate lattice (so that lattice Si:Al ratio is above 25:1) pref. with refluxing 2-10N aq. mineral acid (esp. 3-7N-HCl) for 1-3 hr.; (b) dehydration at 100-200 deg.C for 10-40 hr. esp. in vacuo; then (c) derivatisation with an alkylating, acylating, or silylating agent, e.g. 1-4C alkanols or alkyl halides, dihalodialkylsilanes, or dialkoxydialkylsilanes (so that 1-4 moieties per site are converted to Si(OR) (R = pref. 1-4C alkyl or SiR2X where X = halogen), or at least 2 Si(OH) moieties per site are bridged by Si(R1)q where q = 0-2), esp. MeOH or SiMe2Cl2. A prefd. starting material is clinoptilolite.</p> |
