Synthesis and reactivity in ethylene oligomerization by heteroscorpionate dibromonickel(II) complexes

NNNO‐Heteroscorpionate nickel (II) and cobalt (II) complexes for ethylene oligomerization: the unprecedented formation of odd carbon number olefins

“…Elemental analysis was performed by the microanalytical laboratory at A. N. Nesmeyanov Institute of Organoelement Compounds. Mass spectra under atmospheric pressure electrospray (ESI) were recorded in the full scan mass of positive and negative ions on the dynamic tandem mass spectrometer Finnigan LCQ Advantage (USA), equipped with a mass analyzer oktapol ion trap pump MS Surveyor, Surveyor autosampler, nitrogen generator Schmidlin-Lab F I G U R E 1 Examples of and Ni(II) scorpionate [13] and heteroscorpionate [17] complexes used as precatalysts in ethylene oligomerization (Germany) and a system for collecting and processing the data using the X Calibur program (version 1.3, Finnigan). Transfer capillary temperature of 150 C, voltage field between the needle and counter electrode 4.5 kV.…”

“…[26] Then, 2-[bis(3,5-dimethylpyrazol-1-yl)methyl]-8-methoxyquino line L has been prepared from 8-methoxyquinoline-2-carbaldehyde and bis(3,5-dimethylpyrazol-1-yl)methanone following the synthetic procedure adopted from Higgs and Carrano. [28] (Scheme 1) It was characterized using 1 H and 13 C NMR (SI, Figures S2,S3) (annotations were proposed based on [17,36] ), IR (SI, Figures S4, S5) and elemental analysis.…”

“…[14][15][16] Earlier, we have obtained a number of nickel (II) complexes with heteroscorpionate ligands (Figure 1, b-g), which showed moderate activities towards ethylene oligomerization with predominant formation of butenes. [17] However, nickel halide complexes with tridentate heteroscorpionates easily undergo isomerization [18] yielding ionic complexes [NiL 2 ] +2 [NiHal 4 ] −2 , which are inactive in oligo-/polymerization of ethylene. So thermodynamically stable molecular complexes of nickel halides with heteroscorpionates [19] or scorpionates [20] are obtained only when bulky substituents are introduced.…”

Synthesis of Bis(benzotriazol-1-yl)methane Derivatives by Cobalt-Catalyzed Formation of C-C Bonds

“…In the compounds described in this paper one of the azolyl ring was changed by a six-membered ring, and this situation was already found in the closely related bis(benzoindazol-1-yl)pyridin-2-ylmethane, described early [48]. It is worth noting that compounds based on comparable bis(pyrazol-1-yl)pyridin-2-ylmethane skeleton were recently used for the preparation of coordination compounds acting as catalysts towards ethylene oligomerization and polymerization [49,50]. The three cycles adopt a helical conformation (see a superimposition of both molecules drawn along the H(1)-C(1) vector in Scheme 2; torsion angles are collected in Table 3).…”

High-Throughput Small-Molecule Crystallography at the ‘Belok’ Beamline of the Kurchatov Synchrotron Radiation Source: Transition Metal Complexes with Azomethine Ligands as a Case Study

“…The mean productivity of the beamline in the small-molecule crystallography mode is 25-30 new crystal structures per week and roughly 500 per year. Examples of recently published challenging crystal structures include cage polynuclear metal-containing organosiloxanolates [52][53][54], synthetic analogs of naturally occurring alkaloids [55] and other biologically active substances [56], unstable catalysis-related intermediates [57,58], products of photoinitiated single crystal-single crystal solid-state reactions [59], etc.…”