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Updated: Jun 1, 2026

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Semiexperimental equilibrium structure for cis,trans-1,4-difluorobutadiene by the mixed estimation method
Jean F Demaison1, Norman C Craig
1Laboratoire de Physique des Lasers, Atomes et Molécules, Université de Lille I, 59655 Villeneuve d'Ascq Cedex, France.
Abstract:
The available experimental rotational constants of cis,trans-1,4-difluorobutadiene do not permit a determination of a complete structure. However, this problem, rather frequent in finding structures, may be solved by the mixed estimation method. The experimental ground state rotational constants are corrected for the rovibrational contribution calculated from an ab initio force field. These semiexperimental data are supplemented by structural parameters from ab initio calculations and a weighted least-squares fit allows us to obtain a reasonable structure. The accuracy of the fitted parameters is checked by optimizing a structure at the coupled cluster level. A good agreement is found between the two methods, validating our procedure.
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