Crystal structure and electrical conductivity of nickel 6, 13‐di (p‐tolyl)‐5, 14‐dihydrodibenzo [b,i]‐1,4,8,11‐tetraaza [14]annulene Iodide (Ni (dtdbtaa)I2.58)

Hunziker, M.; Loeliger, H.; Rihs, Grety; Hilti, B.

doi:10.1002/hlca.19810640810

Cited by 21 publications

(3 citation statements)

References 14 publications

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“…Interestingly, the two attached indolenine rings are coplanar with this system; thus the whole molecule (except for the methyl groups) lies in a plane [maximum deviation = 0.043(4) Å for C7], and the methyl groups lie on either side of the plane. In contrast, the planar dibenzotetraaza[14] annulenes with the meso -carbons linked to six-membered aromatic rings showed some degree of twist about the linkages. − The methyl hydrogens H8C and H9C are separated from the propanediiminato H atom, H12, by 2.17 and 2.12 Å respectively, which are shorter than the van der Waals sum (2.4 Å). Selected bond lengths and angles are listed in Table .…”

Section: Resultsmentioning

confidence: 99%

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II

et al. 2013

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A new dibenzotetraaza[14]annulene bearing two 3,3-dimethylindolenine fragments at the meso positions (LH(2)), has been synthesized through a nontemplate method. X-ray crystallography shows that the whole molecule is planar. The basicity of the indolenine ring permits the macrocycle to be protonated external to the core and form LH(4)(2+)·2Cl(-). Yet another structural modification having strong C-H···π interactions was found in the chloroform solvate of LH(2). The latter two modifications are accompanied by a degree of nonplanar distortion. The antiaromatic core of the macrocycle can accommodate a number of metal ions, Mn(III), Fe(III), Co(II), Ni(II) and Cu(II), to form complexes of [Mn(L)Br], [Mn(L)Cl], [Fe(LH(2))Cl(2)](+)·Cl(-), [Co(L)], [Ni(L)], and [Cu(L)]. In addition, the reaction of LH(2) with the larger Pd(II) ion leads to the formation of [Pd(2)(LH(2))(2)(OAc)(4)] wherein the macrocycle acts as a semiflexible ditopic ligand to coordinate pairs of metal ions via its indolenine N atoms into dinuclear metallocycles. The compounds LH(2), [Co(L)], and [Ni(L)] are isostructural and feature close π-stacking as well as linear chain arrangements in the case of the metal complexes. Variable temperature magnetic susceptibility measurements showed thermally induced paramagnetism in [Ni(L)].

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Section: Resultsmentioning

confidence: 99%

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II

et al. 2013

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“…The nickel complexes of dibenzo[b,i]- [1,4,8,11]tetraaza [14]annulene (TAA) and 5,7,12,14-tetramethyl-dibenzo[b,i] [1,4,8,11]tetraaza [14]annulene (TMTAA), as shown below, were amongst the first to be prepared and their properties may be tailored by selective structural modification or ligation. For example, structural studies have shown that TAA complexes and analogues with methyl and aryl groups in the meso-positions, such as nickel-6,13-di(p-tolyl)-5,14-dibenzo[b,i] [1,4,8,11]tetraaza [14]annulene, [Ni II DTTAA] [2] and their Co analogues [3], and nickel-6,13-dimethyl-5, 14-dibenzo[b,i] [1,4,8,11]tetraaza [14]annulene, [Ni II DMTAA] [4] possess predominantly planar macrocyclic ring systems. In contrast, the TMTAA complexes are saddle-shaped due to the steric interaction between the methyl groups and benzene rings.…”

Section: Introductionmentioning

confidence: 99%

Cyclic voltammetry and spectroelectrochemical study of nickel and cobalt diphenyltetraazaannulene complexes

Alexander

Crayston

Dines

2007

Journal of Electroanalytical Chemistry

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“…Dibenzotetraaza[14]annulenes are a class of synthetic macrocyclic ligands that have a planar coordination environment for a wide range of metal cations. − The annulene ring is 14-membered with 16 conjugated π-electrons constituting a formally Hückel antiaromatic system. We recently synthesized the meso-substituted dibenzotetraaza[14]annulene ([LH 2 ]) and its complexes with a number of transition metals, including Ni(II) …”

Section: Introductionmentioning

confidence: 99%

Computational Studies of a Paramagnetic Planar Dibenzotetraaza[14]annulene Ni(II) Complex

et al. 2015

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A square-planar Ni(II) dibenzotetraaza[14]annulene complex substituted with two 3,3-dimethylindolenine groups in the meso positions has recently been synthesized and characterized experimentally. In the solid-state, the Ni(II) complex forms linear π-interacting stacks with Ni···Ni separations of 3.448(2) Å. Measurements of the temperature dependence of the magnetic susceptibility revealed a drastic change in the magnetic properties at a temperature of 13 K, indicating a transition from low-to-high spin states. The molecular structures of the free-base ligand, the lowest singlet, and triplet states of the monomer and the dimer of the Ni complex have been studied computationally using density functional theory (DFT) and ab initio correlation levels of theory. In calculations at the second-order Møller-Plesset (MP2) perturbation theory level, a large energy of 260 kcal mol(-1) was obtained for the singlet-triplet splitting, suggesting that an alternative explanation of the observed magnetic properties is needed. The large energy splitting between the singlet and triplet states suggests that the observed change in the magnetism at very low temperatures is due to spin-orbit coupling effects originating from weak interactions between the fine-structure states of the Ni cations in the complex. The lowest electronic excitation energies of the dibenzotetraaza[14]annulene Ni(II) complex calculated at the time-dependent density functional theory (TDDFT) levels are in good agreement with values deduced from the experimental UV-vis spectrum. Calculations at the second-order algebraic-diagrammatic construction (ADC(2)) level on the dimer of the meso-substituted 3,3-dimethylindolenine dibenzotetraaza[14] annulene Ni(II) complex yielded Stokes shifts of 85-100 nm for the lowest excited singlet states. Calculations of the strength of the magnetically induced ring current for the free-base 3,3-dimethylindolenine-substituted dibenzotetraaza[14]annulene show that the annulene ring is very weakly antiaromatic, sustaining a paratropic ring-current strength of only -1.7 nA/T.

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Crystal structure and electrical conductivity of nickel 6, 13‐di (p‐tolyl)‐5, 14‐dihydrodibenzo [b,i]‐1,4,8,11‐tetraaza [14]annulene Iodide (Ni (dtdbtaa)I_2.58)

Cited by 21 publications

References 14 publications

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II

Cyclic voltammetry and spectroelectrochemical study of nickel and cobalt diphenyltetraazaannulene complexes

Computational Studies of a Paramagnetic Planar Dibenzotetraaza[14]annulene Ni(II) Complex

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Crystal structure and electrical conductivity of nickel 6, 13‐di (p‐tolyl)‐5, 14‐dihydrodibenzo [b,i]‐1,4,8,11‐tetraaza [14]annulene Iodide (Ni (dtdbtaa)I2.58)

Cited by 21 publications

References 14 publications

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions MnIII, FeIII, CoII, NiII, CuII, and PdII

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions MnIII, FeIII, CoII, NiII, CuII, and PdII

Cyclic voltammetry and spectroelectrochemical study of nickel and cobalt diphenyltetraazaannulene complexes

Computational Studies of a Paramagnetic Planar Dibenzotetraaza[14]annulene Ni(II) Complex

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Crystal structure and electrical conductivity of nickel 6, 13‐di (p‐tolyl)‐5, 14‐dihydrodibenzo [b,i]‐1,4,8,11‐tetraaza [14]annulene Iodide (Ni (dtdbtaa)I_2.58)

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II

Indoleninemeso-Substituted Dibenzotetraaza[14]annulene and Its Coordination Chemistry toward the Transition Metal Ions Mn^III, Fe^III, Co^II, Ni^II, Cu^II, and Pd^II