From chemistry-request {*at*} www.ccl.net Thu Feb 11 17:02:12 1999 Received: from broadway.gc.cuny.edu (broadway.gc.cuny.edu [146.96.128.10]) by www.ccl.net (8.8.3/8.8.6/OSC/CCL 1.0) with SMTP id RAA18353 Thu, 11 Feb 1999 17:02:11 -0500 (EST) Received: by broadway.gc.cuny.edu id AA23321; Thu, 11 Feb 1999 17:01:58 -0500 Date: Thu, 11 Feb 1999 17:01:58 -0500 (EST) From: Artem Masunov X-Sender: amasunov # - at - # broadway.gc.cuny.edu Reply-To: Artem Masunov To: Jerry Perlstein Cc: chemistry |-at-| www.ccl.net Subject: More ?? :color of molecules in the solid state In-Reply-To: <36C332EB.167E -8 at 8- chem.chem.rochester.edu> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII > Anik Peeters wrote: > > The molecule I am studying right now has been observed in three different > > polymorphic forms. One has a white colour, another one is yellow and a > > third one is light yellow. I have been trying to relate the yellow and > > light yellow colour to the band gap between the HOMO and LUMO. > On Thu, 11 Feb 1999, Jerry Perlstein wrote: > Before you do anything fancy why don't you visually looked at the > structures to see if there are any molecular interactions which would > suggest charge transfer transitions? I wonder what kind of interactions in homomolecular crystals (except conventional pi-pi stacking) could be considered as charge transfer? Are there CT spectra for sigma-interactions? I would appreciate if Jerry Perlstein (and all CCLers) give me some references for the examples and interpretations. Artem Masunov > __ _________ Artem.Masunov(+ at +)usa.net;tel 212-772-5751;fax212-772-5332 > / \ / _ _ \ text pager: instantmessage |-at-| bigfoot.com (max. 120 char.) > / \\ \\ \\ \ Chemistry Department, Hunter College, City U. of NY > / /\ \\ \\ \\ \ 695 Park Avenue, New York, NY 10021 > / ____ \\ \\ \\ \ --------------------------------------------------- > /__/\__/\__\\__\\__\\__\ > \__\/ \/__//__//__//__/