From chemistry-request@server.ccl.net Sat Oct 19 12:36:16 2002 Received: from mail.szote.u-szeged.hu ([160.114.96.63]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g9JGaFK06800 for ; Sat, 19 Oct 2002 12:36:16 -0400 Received: from ovrisc.mdche.u-szeged.hu (IDENT:qmailr@ovrisc.mdche.u-szeged.hu [160.114.101.224]) by mail.szote.u-szeged.hu (8.9.3/8.8.7) with SMTP id SAA12409 for ; Sat, 19 Oct 2002 18:36:13 +0200 Received: (qmail 1416 invoked by uid 525); 19 Oct 2002 16:36:13 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 19 Oct 2002 16:36:13 -0000 Date: Sat, 19 Oct 2002 18:36:13 +0200 (CEST) From: To: Tarek Mamoun El-Gogary cc: "'CHEMISTRY@ccl.net'" Subject: Re: CCL:solvent cutoff wavelength In-Reply-To: <4C7A402190F4BD4385075D6B739AB4141394F9@mum.mans.edu.eg> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, It is also useful to measure the solvent and the sample separately and extract the solvent spectrum from that of the sample. It can be done by most of theavailable spectrophotometers with a built-in function. Best, Csaba From chemistry-request@server.ccl.net Sat Oct 19 13:56:45 2002 Received: from professor.concordia.ab.ca ([199.185.120.58]) by server.ccl.net (8.11.6/8.11.0) with ESMTP id g9JHuiK08123 for ; Sat, 19 Oct 2002 13:56:44 -0400 Received: from concordia.ab.ca (facroute.concordia.ab.ca [199.185.120.35]) by professor.concordia.ab.ca with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2653.13) id PQCWHNH1; Sat, 19 Oct 2002 12:01:18 -0600 Message-ID: <3DB19839.7040605@concordia.ab.ca> Date: Sat, 19 Oct 2002 11:36:57 -0600 From: Vladimir Pitchko User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.4.1) Gecko/20020314 Netscape6/6.2.2 X-Accept-Language: en-us MIME-Version: 1.0 To: Chemistry Computer List Subject: Structure of sugars Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi! Does somebody know any good article (book, review,...) with ab initio structures of glucopyranose systems? Thanks. -- ------------------------------------------------------- | Dr.Vladimir Pitchko, Assistant Professor | Concordia University College of Alberta | 7128 Ada Blvd. | Edmonton,Alberta, T5B 4E4, Canada | Tel.# (780) 479-9376 Fax # (780) 474-1933 | E-mail: vpitchko@concordia.ab.ca ------------------------------------------------------ From chemistry-request@server.ccl.net Sat Oct 19 00:21:36 2002 Received: from web20606.mail.yahoo.com ([216.136.226.164]) by server.ccl.net (8.11.6/8.11.0) with SMTP id g9J4LaK27921 for ; Sat, 19 Oct 2002 00:21:36 -0400 Message-ID: <20021019042135.74004.qmail@web20606.mail.yahoo.com> Received: from [64.130.222.245] by web20606.mail.yahoo.com via HTTP; Fri, 18 Oct 2002 21:21:35 PDT Date: Fri, 18 Oct 2002 21:21:35 -0700 (PDT) From: Sengen Sun Subject: chemical reaction theories To: chemistry@ccl.net MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Hello, every one I have just posted a third paper in the Chemistry Preprint Server on some fundamental issues of organic chemical reactions. I am seeking some public discussions on the issues I raised in the paper. If any bodies are interested, you may check the paper out. The current paper: “Natural forces as the foundation of theoretical explanations in organic chemsitry” at http://preprint.chemweb.com/orgchem/0210002 The two earlier papers: “Playing the natural puzzles of concerted cycloadditions: what are the tricks behind the scene?” at http://preprint.chemweb.com/orgchem/0201002 “Electron reorganization as the general mechanism of concerted cycloaddition reactions” at http://preprint.chemweb.com/orgchem/0107002 Please feel free to make any comments publicly or individually on these issues. Thanks. Cheers! Sengen Sun PS, The abstract for the current paper: Chemical phenomena are controlled by natural forces and relativity effects. Coulombic and magnetic forces are two types of conflicting forces that must be balanced in any chemical systems. Their interplay leads to diverse chemical phenomena such as anti-aromaticity, stereoselectivity of electrocyclisation reactions, and the periodic table of elements. The magnetic force due to the orbital angular momentum along the ring of a delocalized cyclic organic species is discussed in this paper as one of the control factors in organic chemistry. The most stable state (e.g. aromatic species and the noble gases) can be reached when the interference of these two types of forces reaches a minimum in a closed-shell setting. A strong interference of the two forces can be seen in an unstable antiaromatic species. Like the conjugated pi-systems of aromatic compounds, the transition state of a thermally concerted cycloaddition is a strictly closed-shell species of minimum magnetic interference. A thermal chemical reaction favors a closed-shell pathway in which the conflict between the Coulombic forces and magnetic forces is minimized. The interpretation of physical laws on forces in chemistry could lead to a more uniformed understanding of physical sciences. __________________________________________________ Do you Yahoo!? Y! Web Hosting - Let the expert host your web site http://webhosting.yahoo.com/