GUEST HOST RELATIONSHIPS IN ZEOLITE SYNTHESIS - RING-SUBSTITUTED PIPERIDINES AND THE REMARKABLE ADAMANTANE MIMICRY BY 1-AZONIO SPIRO [5.5] UNDECANES/

This paper explores the contribution to high silica zeolite syntheses based upon derivatives of a six-ring heterocycle, piperidine. The zeol ite product selectivity can be rationalized in terms of the type and l ocation of ring substitution in the derivatives studied as structure-d irecting agents (SDAs) in zeolite crystal growth. A number of new zeol ite products were found as the substitution leads to spatially larger molecules. The pure phase MEL was produced by one very specific SDA. A s well as the synthesis studies presented, a select group of derivativ es built around the azaspiro [5.5] undecane architecture were also stu died as to their hydrophobic transfer from water to chloroform during solvent partitioning studies. One surprising discovery was that a sing le spiro derivative produced five different zeolite products over a ra nge of synthesis conditions, and these five zeolites were initially en countered in studies with a single adamantyl derivative. Attempts were made via molecular modeling to determine why these two disparate SDAs yield almost the same zeolite product selectivities. (C) 1998 Elsevie r Science B.V. All rights reserved.