Catalytic activity correlation of Ni(II), Co(II) and Pd(II) complexes to metal atom net charge

Abstract

The metal atom net charge correlation (MANCC) method was developed in prediction of catalyst activity of asymmetric late-transition metal complexes, 2-quinoxalinyl-6-iminopyridine Ni (II), 2-imino-1, 10-phenanthroline Co(II) and 2-methoxycarbonyl-6-iminopyridine Pd(II) complexes, from the net charge of the metal atom for ethylene polymerization. Dreiding force field was modified according to the X-ray diffraction data. We found that the asymmetric structure of the complexes resulted in a charge difference between two halogen atoms coordinated to the metal atom. In order to remove such contribution we introduced the effective charge Q eff , which was obtained by the charge equilibration (QEq) approach. The results verified the successful introduction of Q eff and showed that the catalytic activities of different complexes are related to central metal atom effective charge. asymmetric catalyst, effective charge, force field, MANCC, QEq

Cooperative effect through different bridges in nickel catalysts for polymerization of ethylene

“…[36] Chen and co-workers reported a rigid conjugated α-diimine backbone in dinuclear Ni and Pd catalysts, and unimodal to bimodal molecular weight distributions of polyethylene were observed. [43][44][45][46][47][48] In the work reported herein, we computed the structures for better understanding of relation between theoretical parameters, interactions and catalyst behaviors. [38] Sun and co-workers synthesized a series dinuclear iminopyridine Ni complexes bearing rigid and rigid/flexible bridges giving oligomeric to oligomeric/polymeric polyethylene.…”

Quantitative Investigation of the Electronic and Steric Influences on Ethylene Oligo/Polymerization by 2‐Azacyclyl‐6‐aryliminopyridylmetal (Fe, Co, and Cr) Complexes

“…More than a dozen years, we have developed various models of organic compounds as ligands for transition metal precatalysts performing high activities toward ethylene reactivity; moreover, the combination of the molecular mechanics (MM) and the charge equilibration (QEq) method was successfully used to correlate the catalytic activity with the net charge of the metal center . Extensively, the advent of the effective net charge Q eff makes the relationship between net charge of metal center and catalytic activity extend to asymmetric complex catalyst . Recently, the density function theory (DFT) combined with QEq method was used to investigate the catalytic activity, achieving the quantitative correlations between the catalytic activity and the effective net charge of metal center …”

Correlating net charges and the activity of bis(imino)pyridylcobalt complexes in ethylene polymerization

“…However, the computation simulations provide reliable tendencies regarding experimental reports, and the catalytic activities were assumed to correlate the electronic factors of the metal complexes [9,10]. Catalytic activities have been investigated by combining molecular mechanics (MM) and QEq charge equilibration method [11], which have successfully assessed the ethylene polymerization by different metal complexes including Ti, Ni and Fe complexes [12][13][14][15][16][17][18]. Recently, we employed DFT-QEq method to correlate the catalytic activities and the net charges of the iron complexes according to the electronegativity of the substituents on ligands [19], providing consistent results to the experimental observations [20,21].…”