Structure and vibrational spectroscopic study of phthalimido-functionalized N-heterocyclic palladium complexes. Correlations between structure and catalytic activity

Publication date: Available online 2 February 2018 Source:Journal of Organometallic Chemistry Author(s): János Mink, Serena L.M. Goh, Manuel P. Högerl, Fritz E. Kühn, Markus Drees, Judith Mihály, Csaba Németh, László Hajba New complexes of Pd(II) with cationic phthalimido-functionalized N-heterocyclic carbene (NHC), the cis-Diacetonitrile(chloro)[1-(2≷-phthalamidoethyl)-3-methylimidazolin-ylidene]palladium(II) Hexafluorophosphate (and its CD3CN derivative) had been successfully used as catalyst in the Suzuki–Miyaura cross-coupling reaction. This complex have been studied by structural (XRD), spectroscopic (infrared, far-infrared and Raman) and theoretical (DFT and normal coordinate calculations) methods. Palladium is bound to two acetonitrile ligands and one-one chloride ion and phthalimido-functionalized imidazolium salt, [3-methyl-1-(2≷-phthalimidoethyl) imidazolium] (L = ligand) in a square–planar cis arrangement. The molecular structure of the [PdCl(NCCH3)2L]+ was obtained by XRD and DFT geometry optimization. The two acetonitrile ligands exhibited two different Pd-N bonds a shorter one 2.080 Å (opposite to Cl ion) and a longer one 2.120 Å (trans to heterocyclic ligand). The cationic [PdCl(NCCH3)2L+] complex has as much as 132 fundamental modes and practically all of them have been assigned. The complex has no symmetry elements, but interpretation has been performed on the basis of local symmetries of its fragments. Tans-conformation of ...
Source: Journal of Organometallic Chemistry - Category: Chemistry Source Type: research