Chelate von Chinolin‐8‐ol‐Derivaten. XII. Die Kristall‐ und Molekülstruktur von Bis(7‐isopropylchinolin‐8‐olato)nickel(II)

Friedrich, Alwin; Uhlemann, E.; Weller, F.

doi:10.1002/zaac.19926150908

Cited by 3 publications

(1 citation statement)

References 14 publications

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“…On the other hand, Ni complex 2 shows square-planar coordination around the central nickel atom and the Niq 2 part has almost complete planarity, as shown in Figure 2b. Such a planar structure has been reported in bis(7-isopropyl-8quinolinato)nickel(II) complex and bis-(4-methylpyridine)bis(8-quinolinolato)nickel(II) complex [30,31]. Because the dihedral angles between the 1,3-dithiole rings that connect to the amide bond and 8-quinolinato parts are calculated to be 8.6 • and 11.6 • in complex 2, the intramolecular interaction between the TTF and Niq 2 parts is considered to be stronger through more planar structures of TTF-8-quinolinato ligands around the amide bonds than Zn complex 1.…”

Section: Molecular Orbital Calculationsupporting

confidence: 63%

Synthesis and Physical Properties of Tetrathiafulvalene-8-Quinolinato Zinc(II) and Nickel(II) Complexes

2021

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To develop donor–acceptor–donor (D–A–D) type new photo-electric conversion materials, new tetrathiafulvalene (TTF)-Mq2-TTF complexes 1 and 2 were synthesized, where two bis(n-hexylthio)tetrathiafulvalene moieties were attached to the Mq2 part (1: M = Zn, 2: M = Ni, q = 8-quinolinato) through amide bonds. UV-Vis absorption spectra of these complexes showed strong and sharp absorption maxima at 268 nm and small absorption maxima around 410 nm, corresponding to those of Znq2 and Niq2 parts. Furthermore, complexes 1 and 2 exhibited absorption tails up to a much longer wavelength region of ca. 700 nm, suggesting the appearance of charge transfer absorption from TTF to the Mq2 parts. The photoelectrochemical measurements on the thin films of these complexes casted on ITO-coated glass substrates suggest that positive photocurrents can be generated by the photoinduced intramolecular electron transfer process between the TTF and Mq2 parts.

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Section: Molecular Orbital Calculationsupporting

confidence: 63%

Synthesis and Physical Properties of Tetrathiafulvalene-8-Quinolinato Zinc(II) and Nickel(II) Complexes

2021

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DFT Computational Design of a Ligand‐Driven Light‐Induced Mechanism for Spin‐State Switching

2013

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A new ligand-driven light-induced spin-state switching mechanism has been designed based on B3LYP*/6-311++G(d,p) DFT calculations of a series of Co II , Ni II , and Cu II complexes with photochromic 2H-chromene (2H-1benzopyran) ligands 4-8 functionalized with N donor groups. The photoinduced electrocyclic rearrangements of the bischelate four-coordinate Ni II complexes with the ring-closed forms of the ligands, all with high-spin ground electronic states, are predicted to lead to the formation of a mixture of approximately equal amounts of the diamagnetic squareplanar and paramagnetic pseudo-tetrahedral isomers of these complexes containing ring-opened o-quinonoid forms of the ligands. Of the Co II complexes, only that with the 2Hchromen-8-amine ligand 4 exhibits the properties required for manifestation of the photoinitiated spin-state switching. No local minima corresponding to four-coordinate copper [a]4203 complexes with ring-closed isomers of the functionalized 2Hchromenes were located on the respective potential energy surfaces. In their ring-closed forms, 2H-chromenes react with Cu II ions to give two-coordinate Cu I complexes, whereas ring-opened o-quinonoid isomers form four-coordinate bischelate Cu II complexes. In the Ni II complexes with isomeric forms of 2H-pyrano[3,2-h]quinoline ligand 8, the counterions Cland even BF 4 enter into the coordination sphere of the central atom to form stable six-coordinate metal complexes with high-spin ground states. The predicted capacity of the Ni II complexes for light-induced spin-state switching is retained with the bulkier BPh 4 counterion. The low-spin state of the ion-pair formed by the complex with the ring-opened form of ligand 8 is 10.5 kcal mol -1 more energetically favorable than the high-spin form.complexes leading to the light-induced excited spin-state trapping (LIESST), [3] which is an essentially cooperative effect dependent on the crystal packing and counterions. [4] The intramolecular mechanisms of magnetic bistability, which are represented by valence tautomeric rearrangements between redox isomers of the transition metal complexes formed by noninnocent ligands and are driven by electron transfer between a metal ion and the ligand [5] and various ramifications of spin-crossover processes in solution, provide for switching between the low-spin (LS) and high-spin (HS) states of the metal complexes. Among the latter are ligand-driven light-induced spin change (LD-LISC) [6] rearrangements and the recently discovered lightdriven coordination-induced spin-state switching (LD-CISSS) rearrangements [7] caused by reversible changes of the coordination number of a metal center. Whereas the LIESST effect is based on the trapping of a metastable excited spin-state of a metal complex, the LD-LISC and LD-CISSS mechanisms provide for the efficient spin-state switching through light-induced isomerizations of photochromic ligands that affect the ligand field of a complex (LD-LISC) or modify steric conditions to allow the binding of an additional donor center to th...

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Übergangsmetallorganische Reaktionskaskaden zum Aufbau höher aggregierter Systeme: Nickelacyclische Carboxylate als Precursoren für die Synthese eines Oxinato‐Nickel(II)‐Tetramers

Langer¹,

Görls²,

Gillies³

et al. 2005

Zeitschrift anorg allge chemie

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reacts with the nickelacycle [(py) 2 Ni-CH 2 CH 2 -COO] under formation of the thermically stable nickelalactones [(2)Ni-CH 2 CH 2 -COO] (4) the solid state structure of which was determined by an X-ray crystallographic analysis. In 4 the ligand acts as a six-membered chelating ligand with P,N coordination. According to the NMR spectrathis structure is present in solution as well. However, the stronger electron-withdrawing diphenyl-8-0xychinolylphosphinite reacts under similar conditions in further reactions yielding the tetranuclear oxi- EinleitungObwohl die thermische Zersetzung metallorganischer Verbindungen für die Herstellung anorganischer Materialien (Metallen, Metalloxiden u. a.) von erheblicher praktischer Bedeutung ist, werden metallorganische Reaktionen nur selten zur Konstruktion wohl definierter höher organisierter anorganischer Systeme genutzt. Eine wesentliche Ursache für dieses Defizit besteht darin, dass die Steuerung einer Reaktionskaskade typischer übergangsmetallorganischen Reaktionen meistens schwierig zu bewerkstelligen ist. Oft erfolgt unerwünschte Zersetzung, und vielfach sind die Reaktionen so unselektiv, dass zahlreiche Folgeprodukte entstehen.Um das möglicherweise vorhandene Synthesepotential auszuloten, haben wir am Beispiel von nickelacyclischen Carboxylaten des Typs [(L-LЈ)Ni-CH 2 CH 2 -COO] untersucht, ob daraus wohldefinierte höher aggregierte anorganische Systeme in guten Ausbeuten gebildet werden können. Dabei können die prinzipiellen Stärken dieser metallorgani-2719 nato-diphenylphosphinato-Ni(II) complex 6 in the presence of oxygen. The structure of 6 was determined by an X-ray analysis. The formation of 6 is the result of a reaction cascade of at least five metal-assisted reactions which occur step by step, and to some extend in parallel reactions.

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Chelate von Chinolin‐8‐ol‐Derivaten. XII. Die Kristall‐ und Molekülstruktur von Bis(7‐isopropylchinolin‐8‐olato)nickel(II)

Cited by 3 publications

References 14 publications

Synthesis and Physical Properties of Tetrathiafulvalene-8-Quinolinato Zinc(II) and Nickel(II) Complexes

Synthesis and Physical Properties of Tetrathiafulvalene-8-Quinolinato Zinc(II) and Nickel(II) Complexes

DFT Computational Design of a Ligand‐Driven Light‐Induced Mechanism for Spin‐State Switching

Übergangsmetallorganische Reaktionskaskaden zum Aufbau höher aggregierter Systeme: Nickelacyclische Carboxylate als Precursoren für die Synthese eines Oxinato‐Nickel(II)‐Tetramers

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