lone-pair-orientation in Furan

From: Inge Muszynski <inge.muszynski "at@at" uni-tuebingen.de>
Subject: lone-pair-orientation in Furan
Date: Thu, 20 Aug 1998 19:10:18 +0200

 Dear CCL'lers,
 I have got a question concerning the lone-pair-orientation of the oxygen in
 Furan or in other 5-cycled heteroaromatic systems like 1,3,4-Thiadiazol etc.
 Due to the planar character of Furan I would suppose a sp2-hybridisation for
 the oxygen and an in-plane-orientation for its lone-pair. Surprisingly I
 have found  an 0sp3 for Furan in the fragmental library of my molecular
 modelling software SYBYL.
 How to think about this?
 Many thanks in advance.
 Bye Inge Muszynski