Homo- and heterometallic carboxylate cage complexes as precatalysts for olefin polymerization—Activity enhancement through “inert metals”

Lassahn, Paul-Gerhard; Lozan, Vasile; Timco, Grigore A.; Christian, Paul; Janiak, Christoph; Winpenny, Richard E. P.

doi:10.1016/j.jcat.2003.10.028

Cited by 93 publications

(66 citation statements)

References 68 publications

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“…For the past four decades, these species have been studied as precursors for metal oxide nanoparticles, [7] novel magnetic materials, [8] and polymerization catalysts. [9] Coordination complexes of higher nuclearity, such as {Ni 11 }, [10] or {Co 14 } [11] frequently comprise corner-, edge-, or face-sharing aggregates of M II 4 O II 4 . As such, the generation of isostructural metalligand frameworks is especially important as they allow systematic, comparative studies of their complex magnetic phenomena and the possibility to precisely position heterometal atoms within a given architecture.…”

mentioning

confidence: 99%

Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

et al. 2007

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Full compositional and structural control in the high-nuclearity coordination clusters of transition-metal cations is a crucial synthetic target, and is motivated by these species complex electronic and magnetic properties which single them out as metalloenzyme models, [1] nanoscale containers and catalysts, [2] quantum computing components, [3] and molecular magnets.[4] Strategies for their synthesis range from the use of multifunctional organic ligands [5] to the controlled production of molecular sections of solid-state structures, such as those of transition-metal oxides.[6] In most instances the resulting metal frameworks are derived from various archetypal condensed substructures, such as (distorted) M 4 L 4 cubanes (M = metal, L = O, N, etc.). Such cubanes constitute a class of discrete compounds such as complexes based on Ni 4 O 4 or Co 4 O 4 structures, which themselves represent sections of their respective oxides. For the past four decades, these species have been studied as precursors for metal oxide nanoparticles, [7] novel magnetic materials, [8] and polymerization catalysts.[9] Coordination complexes of higher nuclearity, such as {Ni 11 }, [10] or {Co 14 } [11] frequently comprise corner-, edge-, or face-sharing aggregates of M II 4 O II 4 . As such, the generation of isostructural metalligand frameworks is especially important as they allow systematic, comparative studies of their complex magnetic phenomena and the possibility to precisely position heterometal atoms within a given architecture. However, while several almost isostructural compounds of Ni II and Co II exist, including M 4 O 4 cubane structures, because of their very similar coordination chemistry, [12] these are invariably of low nuclearity, and systems exceeding ten metal centers are rare.[13] Correspondingly, mixed-metal isostructures (i.e. structures incorporating both Ni II and Co II centers in varying ratios that are distributed over the metal framework of a coordination cluster) can be generated, yet site-specific occupation is frequently subject to binomial statistics and cannot be resolved by diffraction techniques. In such situations, as we demonstrate herein, magnetic properties can be used to discern between the possible intramolecular distribution scenarios and indicate how narrow the distribution curves are for (cocrystallizing) compositions (of the typeHerein, we demonstrate the use of templating and multifunctional ligands to facilitate the directed assembly of archetypal isostructural Ni [14]These clusters comprise three M 4 O 4 cubane units symmetrically arranged around a central templating carbonate anion and the intact clusters {M 12 } can be detected in solution using cryospray mass spectrometry.[15] Moreover, isostructural mixed Ni:Co clusters of specific composition can be accessed since the pH value of the reaction solution (i.e. an additional reaction parameter besides the stoichiometric reaction ratio of Ni and Co) is used to differentiate the relative population of the metal sites in the {M 12 } system. ...

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Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

et al. 2007

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“…Carboxylate complexes have been widely studied in recent years duetotheir interestingcoordinationchemistry allowing forunusuals tructuralf eaturesa nd leadingt ov arious physical and chemical properties and practical applications in fields of dyes, extractants, drugs, pesticides and catalysts [1][2][3][4]. In recent years, the heavy element cadmium has received increased attention for its impact on plants andtoxicity to humans as well as the luminescent properties of its complexes [5][6].…”

Section: Discussionmentioning

confidence: 99%

Crystal structure of diaqua(5-nitrosalicylate)cadmium(II), Cd(H2O)2(C7H7NO7)

Jin¹,

Chen²,

Ge³

et al. 2011

Zeitschrift Für Kristallographie - New Crystal Structures

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C 7 H 7 CdNO 7 ,triclinic, P1 (no. 2), a =7.0850(6) Å, b =7.5509(7) Å, c =10.713(1) Å, a =104.696(1)°, Source of materialCrystals of diaqua(5-nitrosalicylate)cadmium(II) were formed during an experiment to synthesize the mixed-ligand cadmium complex. As olution of cadmium acetate dihydrate (27 mg, 0.1 mmol) in 5m Lo fM eOH was added to aM eOH solution (3 mL) containing 3,5-dimethylpyrazole (19.2mg, 0.2 mmol) and 5-nitrosalicylic acid (36.6mg, 0.2 mmol), under continuous stirring. The solution was stirred for about 3h at room temperature, a small amount of precipitate formed, then af ew drops of concentrated ammonia was added till thep recipitate dissolved completely. The clear solution was filtered into the test tubeand after several days, colorless block crystals were obtained by slow evaporationofthe ammonia solution at ambient temperature. Experimental detailsAllHa toms attached to Ca toms were fixed geometrically and treated as riding with d(C-H) =0.93 Åwith U iso (H) =1.2 U eq (C). Ha toms of water molecule were located in difference Fourier mapand included in the subsequent refinement using restraints of d(O-H) =0.85(1) Åwith U iso (H) =1.5 U eq (O). In the last stage of refinement, they were treated as riding on the Oatom.

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“…Carboxylate complexes have been much investigated in recent years due to their interesting coordination chemistry allowing for unusual structural features and leading to various physical and chemical properties and practical applications [1][2][3][4]. Among them copper(II) carboxylates are of special interest as they are easily obtained as polynuclear units having relevance to magnetic materials [5] and biology [6].…”

Section: Discussionmentioning

confidence: 99%

Crystal structure of aqua-ammine-(μ-succinato)copper(II) dihydrate, Cu(H2O)(NH3)(C4H4O4) ·2H2O

Jin¹,

Wang²,

Cao³

et al. 2009

Zeitschrift Für Kristallographie - New Crystal Structures

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C 4H13CuNO7,m onoclinic, P12/c1(no. 13), a =8.434(3) Å, b =7.230(3) Å, c =8. Source of materialCrystals of aqua-ammine-(m-succinato)copper(II) dihydrate were unexpectedly formed during an attempt to synthesize the mixed ligand copper complex. Am ixture of copper chloride dihydrate (34.2 mg, 0.2 mmol), NaOH (16 mg, 0.4 mmol), succinic acid (23.6 mg, 0.2 mmol), and 5,7-dimethyl-1,8-naphthyridine-2-amine (35 mg, 0.2 mmol), in ethanol (10 ml) was refluxed for 1h.The resulted light blue precipitate was collected and dissolved in 3mlofconcentrated ammonia. Blue block-like crystals were obtained by slow evaporation of the ammonia solution at ambient temperature. Experimental detailsHydrogen atoms of methylene groups were only placed in corresponding calculated positions [d(C-H) =0.97 Å]. Positions of hydrogen atoms of water and ammonia molecules were located from the difference Fourier syntheses and refined. All U iso values were restrained on U eq values of the parent atoms.

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Homo- and heterometallic carboxylate cage complexes as precatalysts for olefin polymerization—Activity enhancement through “inert metals”

Cited by 93 publications

References 68 publications

Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

Crystal structure of diaqua(5-nitrosalicylate)cadmium(II), Cd(H2O)2(C7H7NO7)

Crystal structure of aqua-ammine-(μ-succinato)copper(II) dihydrate, Cu(H2O)(NH3)(C4H4O4) ·2H2O

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Homo- and heterometallic carboxylate cage complexes as precatalysts for olefin polymerization—Activity enhancement through “inert metals”

Cited by 93 publications

References 68 publications

Structural and Compositional Control in {M12} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

Structural and Compositional Control in {M12} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

Crystal structure of diaqua(5-nitrosalicylate)cadmium(II), Cd(H2O)2(C7H7NO7)

Crystal structure of aqua-ammine-(μ-succinato)copper(II) dihydrate, Cu(H2O)(NH3)(C4H4O4) ·2H2O

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Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry

Structural and Compositional Control in {M₁₂} Cobalt and Nickel Coordination Clusters Detected Magnetochemically and with Cryospray Mass Spectrometry