Dear CCL users: I am playing around with a keto/enolate formation reaction catalyzed by gernal acid and base(methyl amine/ammonium ion). I would like to locate the TS structure in organic solvent such as THF or cyclohexane based on the TS structure previously located in gas phase. Despite semi-empirical method AM1 in spartan was able to locate the initial strucuture in organic solvation, but further optimization in Gaussian was unsuccesful and failed many times.(Gaussian program complain that there is no negative engien vector while desired one)I am not sure if the initial structure located in spartan was not good enough or there was some trap in refinement in Gaussian.Can anybody with experiences of this kind of reaction in solvation give me any suggestions? Your answer will be highly appreciated! Have a good one. The keyword I am using in SCRF caculation #HF/6-31G(d) OPT=(Tight,TS) SCRF=(PCM,Read,Solvent=THF) Freq Test I also attached the PDB file of the TS in gas phase (located in HF/6-31G(d)) and the TS in hexadacane and water.( located in AM1 ) if you are interested. Cheers Yong. L. Y. (o)631-632-5796 Department of Chem. SUNY-Stony Brook
Attachment:
12_01_SE_hexa_output.pdb
Description: Protein Databank data
Attachment:
12_01_SE_water_output.pdb
Description: Protein Databank data
Attachment:
11_27_enolate_output_01.PDB
Description: Protein Databank data