The crystal structure of bis-(<i>N</i>-isopropylsalicylaldiminato)nickel(II)

Fox, M. R.; Orioli, Pierluigi; Lingafelter, E. C.; Sacconi, L.

doi:10.1107/s0365110x64002997

Cited by 69 publications

(27 citation statements)

References 4 publications

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“…They exhibit either planar (Akhtar & Drew, 1982) or tetrahedral (Fox et al, 1964) coordination around the central atom. Also, widening of the coordination sphere by additional metal'metal (Shkol'nikova et al, 1970) or metal-base (Hall et al, 1968) interactions can occur.…”

Section: Commentmentioning

confidence: 99%

[N,N'-Bis(salicylidene)ethylenediaminato-N,N',O,O']platinum(II)

Sawodny¹,

Thewalt²,

Potthoff³

et al. 1999

Acta Crystallogr C

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Stabilité d'ondes périodiques dans des EDP hamiltonniennes Résumé Les équations aux dérivées partielles munies d'une structure hamilton-nienne sont connues pour admettre des familles entières d'ondes progressives périodiques. C'est le cas pour l'équation de Korteweg-de Vries et de nombreux autres modèles plus ou moins classiques. L'étude de la stabilité de ces ondes en est cependant encore à ses balbutiements. Plusieurs approches sont pos-sibles. L'une d'elles est bien sûr l'analyse spectrale des équations linéarisées. Toutefois, le lien avec la stabilité non-linéaire, et en fait la stabilité orbitale puisque ce sont des problèmes invariants par translation, est loin d'être clair. Car on ne peut espérer qu'une stabilité spectrale neutre, étant donné que la structure hamiltonnienne exclut l'existence d'un trou spectral, et ce même en faisant abstraction de la valeur propre nulle, liée à l'invariance par translation. D'autres méthodes pour étudier la stabilité des ondes progressives périodiques consistent à tirer parti de la structure sous-jacente. C'est naturellement le cas de l'approche variationnelle. Celle-ci consiste à utiliser le hamiltonnien, ou plus précisément une fonctionnelle modifiée pour tenir compte des autres quantités conservées, comme fonction de Lyapunov. Lorsqu'elle s'applique, cette mé-thode est très efficace et donne directement accès à la stabilité orbitale. Une troisième voie est la théorie de la modulation, dont les fondements ont été posés par Whitham à l'orée des années 1970. L'objectif est ici de présenter quelques résultats récents, valant pour des équations et systèmes du type de l'équation Korteweg-de Vries, qui mettent en relation les approches spectrale, variationnelle et modulationnelle. Abstract Partial differential equations endowed with a Hamiltonian structure, like the Korteweg-de Vries equation and many other more or less classical models, are known to admit rich families of periodic travelling waves. The stability theory for these waves is still in its infancy though. The issue has been tackled by various means. Of course, it is always possible to address stability from the spectral point of view. However, the link with nonlinear stability-in fact, orbital stability, since we are dealing with space-invariant problems-, is far from being straightforward when the best spectral stability we can expect is a neutral one. Indeed, because of the Hamiltonian structure, the spectrum of the linearized equations cannot be bounded away from the imaginary axis, even if we manage to deal with the point zero, which is always present because of space invariance. Some other means make a crucial use of the underlying structure. This is clearly the case for the variational approach, which basically uses the Hamiltonian-or more precisely, a constrained functional associated with the Hamiltonian and with other conserved quantities-as a Lyapunov function. When it works, it is very powerful, since it gives a straight path to orbital stability. An alternative is the modulational approach, following ...

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Section: Commentmentioning

confidence: 99%

[N,N'-Bis(salicylidene)ethylenediaminato-N,N',O,O']platinum(II)

Sawodny¹,

Thewalt²,

Potthoff³

et al. 1999

Acta Crystallogr C

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“…1. The dihedral angle between the coordination plane defined by atoms Ni, N(1), and N(2) and the coordination plane defined by atoms Ni, N(I'), and N(2') (primes refer to atoms related to the corresponding independent atoms by the twofold symmetry) is 88.7 (3) °, a value slightly different from the corresponding value of 89.6 (4) ° obtained for the cobalt complex; it is appreciably larger than the equivalent values of 81.5 and 85.3 ° , respectively, in the distorted tetrahedral complexes bis-(N-isopropylsalicylaldiminato)Ni(II) (Fox et al, 1964)and bis-(N-isopropyl-3-ethylsalicylaldiminato)Ni(II) (Braun & Lingafelter, 1967), which contain less bulky sec-alkyl groups attached to the ligand parts. Among the class of Nsubstituted Schiff base and fl-ketoaminine nickel(II) complexes, the present compound possesses the maximum molecular tetrahedrality yet determined by X-ray diffraction -a tetrahedrality which seems to persist in solution (Holm & O'Connor, 1971), in contrast with those complexes having less bulky ligands such as Nsec-alkylsalicylaldimine.…”

Section: Solution and Refinement Of The Structurementioning

confidence: 70%

“…Among the best-studied salicylaldimine complexes, the three-dimensional structures of only two complexes, bis-(N-isopropylsalicylaldiminato)Ni(II) (Fox, Orioli, Lingafelter & Sacconi, 1964) and bis-(N-isopropyl-3-ethylsalicylaldiminato)Ni(II) (Braun & Lingafelter, 1967), have been shown to be tetrahedral by X-ray analyses. Further information is to be derived from crystallographic determination of the stereochemistry of complexes involving different basic ligands and containing the bulkier t-butyl group.…”

Section: Introductionmentioning

confidence: 99%

Structure of a bis-bidentate metal complex, bis-(N-t-butylpyrrole-2-carbaldimino)nickel(II). Analysis of its configurational disorder in the crystalline state

Wei¹,

Einstein²

1972

Acta Crystallogr Sect B

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The crystal and molecular structure of a bis-bidentate nickel complex, (CgHI3N2)zNi(II), has been determined from a single-crystal X-ray analysis. The unit-cell data are a= 16-777 (13), b=7.507 (6), c= 15.378 (11) A, Z=4, space group Pbcn. Counter data to 20=48 ° (Mo K~ radiation) were measured with an Oak Ridge computer-controlled diffractometer. The structure was solved by heavy-atom techniques and refined by the full-matrix least-squares method to R(F)= 0"102, based on 1160 independent nonzero reflections, or 0.049 for the 649 reflections with Fo2_> 3tr(F2). The molecule has C2 symmetry with a crystallographic twofold axis passing through the metal atom. The structure is partly disordered in that the t-butyl group appears to have two alternative orientations of equal occupancy. The configuration around the nickel atom is pseudo-tetrahedral with a dihedral angle of 88-7 (3) ° between the plane defined by the Ni, N(I), and N(2) atoms and the plane defined by the Ni, N(I'), and N(2') atoms. The two independent Ni-N bond distances, 2.032 (4) and 1.935 (5) ,~,, are distinctly different. The intrachelate N-Ni-N angle of 83.7 (4) ° is much smaller than any of the interchelate N-Ni-N angles, which range from 116.7 to 132"7 °. The N...N 'bite' distance in the five-membered ring NiN2C~ is 2.647 (7) ~. The pyrrole-2.carbaldimine ligand is nearly planar.

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“…Interestingly, the Ni-O distance of 1.84(1) Ä is intermediate between the Ni-O distances of 1.80 Ä found in bis-(N-methylsalicylaldimine> nickei(II) (Frassor et al, 1959) which has a planar coordination and 1.89 Ä found in bis-(N-isopropyi salicylaldiminato)mckeI(II) (Fox et al, 1964) which has a tetrahedral coordination.…”

Section: Structure Determination and Refinementmentioning

confidence: 75%

Crystal structure of bis(N-2-phenyl-ethyl salicylideneiminato)nickel(II)

Ravikumar¹,

Rajan²

1986

Zeitschrift Für Kristallographie - Crystalline Materials

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Bis(N-2-phenyl-ethyl salicyUdenemiinato)mckel(II) crystallizes in themonoclinicsystem, Space groupi>2i/nwitha = 6.088(3), 6 = 13.601(2), c = 14.862(3) Ä, a = 90.3(2)° and Z = 2. The intensity data were coUected using a CAD-4 difTractometer with MoAa radiation. The structure was determined by Patterson and Fourier methods (R = 0.061 for 1100 MoATa reflections). An interesting result of this structure determination is the confirmation of the Square planar coordination of the nickel(II) ion in this complex. The Ni-O and Ni-N bond lengths have values 1.84(1) and 1.93(1) Ä, respectively. The two aromatic rings are planar and the angle between these planes is 64.1(3)°. IntrodnctionThe structures of the coortUnation Compounds of nickel(II) are of considerable interest because the ion is known to adopt several difTerent coordina-

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The crystal structure of bis-(N-isopropylsalicylaldiminato)nickel(II)

Cited by 69 publications

References 4 publications

[N,N'-Bis(salicylidene)ethylenediaminato-N,N',O,O']platinum(II)

[N,N'-Bis(salicylidene)ethylenediaminato-N,N',O,O']platinum(II)

Structure of a bis-bidentate metal complex, bis-(N-t-butylpyrrole-2-carbaldimino)nickel(II). Analysis of its configurational disorder in the crystalline state

Crystal structure of bis(N-2-phenyl-ethyl salicylideneiminato)nickel(II)

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