Effect of axial anthracene ligands on the luminescence of trinickel molecular wires

Cotton, F. Albert; Chao, Hui; Li, Zhong; Murillo, Carlos A.; Wang, Qingsheng

doi:10.1016/j.jorganchem.2007.07.025

Cited by 20 publications

(9 citation statements)

References 56 publications

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“…In the trinickel core [Ni 3 (dpa) 4 ] 2+ , the average Ni-N distance for two terminal Ni ions is 2.089 Å and the average central Ni-N distance is 1.904 Å. These average Ni-N distances are very similar to those of other trinickel metal complexes [7][8][9][10], illustrating that the axial ligands only tune the Ni-Ni distances through the self-adjustment of the structural parameters of the helix.…”

Section: Resultssupporting

confidence: 61%

An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O

Zheng¹,

Zhu²

2011

Crystals

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An unsymmetrical trinickel metal complex, [Ni3(dpa)4(4-sb)(H2O)]×3H2O (1), where dpa is a 2,2’-dipyridylamine anion and 4-sb is 4-sulfobenzoate dianion, was synthesized and characterized by X-ray crystallography, IR, elemental analysis, fluorescence, and cyclic voltammetry. The molecular structure of 1 is a cluster with a linear trimer. The extended structure is a 3D architecture assembled by hydrogen bonds. The 4-sulfobenzoate axial replacement leads to the change of Ni-Ni distances, the shift of the fluorescence emission, and the reversible one-electron reduction process without oxidation process

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Section: Resultssupporting

confidence: 61%

An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O

Zheng¹,

Zhu²

2011

Crystals

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“…This difference (vide infra) greatly influences the magnetism. For comparison, the calculated values of d for the outer units of other Ni 3 6+ EMACs are 0.289 and 0.278 Å in Ni 3 (dpa) 4 Cl 2 ,17 0.242 and 0.235 Å in Ni 3 (dpa) 4 (CH 3 CN) 2 ,9e 0.238 Å in Ni 3 (depa) 4 (CH 3 CN) 2 ,9e 0.279 and 0.289 Å in Ni 3 (dpa) 4 (AnCOO) 2 9h. For the oxidized species containing Ni 3 7+ cores, the d distances are 0.102 Å for [Ni 3 (dpa) 4 ](PF 6 ) 3 ,16 and 0.103 Å for [Ni 3 (depa) 4 ](PF 6 ) 3 9e.…”

Section: Resultsmentioning

confidence: 90%

Unusual Magnetism of an Unsymmetrical Trinickel Chain

et al. 2008

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An extended metal atom chain (EMAC) compound with an unsymmetrical trinickel core and the formula [Ni3(dpa)4(CH3CN)](PF6)2·2CH2Cl2 (1·2CH2Cl2, dpa is the anion of 2,2′‐dipyridylamine) has the central Ni atom in an essentially square‐planar configuration. Besides having four equatorial nitrogen atoms, the two terminal metal centers have axial interactions that are notably different with one having a strongly bound acetonitrile molecule with a Ni(3)–N(3) distance of 2.108(5) Å while the other unit has a very weak interaction with an axial PF6 anion [Ni(1)···F(1) separation of 2.690 Å]. In these outer units, the Ni(3) atom is pulled out of the idealized plane of the four equatorial nitrogen atoms by 0.239 Å, while in the one with an axial PF6 anion the metal atom is pulled from the plane of the equatorial nitrogen atoms by only 0.097 Å. In 1 there are two unpaired electrons and an S = 1 state prevails from ca. 25 to 300 K. This magnetic behavior differs considerably from that of symmetrical trinickel EMACs with two strongly pyramidal terminal nickel atoms. A discussion of the effect of various axial ligands on the geometry of the terminal nickel atoms is provided. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

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“…Lapinte et al demonstrated the feasibility of 9,10-diethynylanthracene as bridging moiety between two iron centers, displaying excellent π-electron delocalization properties . Subsequent photophysical studies of compounds with both bridging 9,10-diethynylanthracene and monodentate 9-ethynyl anthracene revealed anthracene-based fluorescences with significantly reduced quantum yields compared to the free ligand. , The trinickel extended metal atom chain compound bearing axial 9-ethynylanthracene was reported by Cotton and displays an anthracene-based fluorescence red-shifted from that of the free ligand . 1-Ethynyl naphthalene was used as the capping ligand of a planar tricopper(I) cluster, which displays unusually long phosphorescence lifetimes from predominantly ligand-based emissive states …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterizations of Macrocyclic Cr(III) and Co(III) 1-Ethynyl Naphthalene and 9-Ethynyl Anthracene Complexes: An Investigation of Structural and Spectroscopic Properties

2018

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Reported herein are the syntheses and structural and emission spectroscopic characterizations of new Cr(HMC) and Co(cyclam) complexes bearing fluorophore alkynyl ligands, where HMC and cyclam are 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane and 1,4,8,11-tetraazacyclotetradecane, respectively. Two Cr(III) bis-1-ethynylnaphthalene (CNp) complexes, trans-[Cr(HMC)(CNp)]Cl ([1]Cl) and cis-[Cr(HMC)(CNp)]Cl ([2]Cl), were prepared from the reactions between trans/cis-[Cr(HMC)Cl]Cl and lithium 1-ethynylnaphthalene (LiCNp) in yields of 73 and 66%, respectively. Also investigated are Co(cyclam) complexes bearing both CNp and CANT (ANT = 9-anthryl), namely [Co(cyclam)(CAr)Cl]Cl (Ar = ANT ([3]Cl), Np ([4]Cl)), [Co(cyclam)(CNp)(NCCH)](OTf) ([5](OTf)), and [Co(cyclam)(CNp)]OTf ([6]OTf). Complexes [3]Cl (72%) and [4]Cl (67%) were prepared from the reaction between [Co(cyclam)Cl]Cl and MeSiCANT or MeSiCNp, respectively, in the presence of triethylamine. The reaction of [4]Cl with excess silver triflate in CHCN yielded complex [5](OTf) (78%), which was reacted with HCNp in the presence of triethylamine to form complex [6]OTf in 39% yield. Single crystal X-ray diffraction studies of [1], [3], [4], and [6] revealed a pseudo-octahedral geometry around the Cr(III) or Co(III) center with the tetraaza-macrocyclic ligand occupying the equatorial plane and the alkynyl- and/or chloro-ligand occupying the apical positions. The absorption spectra of complexes [1] and [2] display structured d-d bands between 400 and 550 nm, a feature that is absent in the d-d absorption of the Co(III) complexes [3]-[6]. Contrasting emission behaviors were observed: the Cr(III) complexes display metal-centered phosphorescence, while the Co(III) species exhibit ligand-based fluorescence. Time-delayed phosphorescence measurements revealed lifetimes of 447 and 97 μs for [1] and [2] at 77 K, respectively, and a room temperature lifetime of 218 μs for [1].

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Effect of axial anthracene ligands on the luminescence of trinickel molecular wires

Cited by 20 publications

References 56 publications

An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O

An Unsymmetrical Trinickel Metal Complex with 4-Sulfobenzoate Axial Ligand: [Ni3(dpa)4(4-sb)(H2O)]×3H2O

Unusual Magnetism of an Unsymmetrical Trinickel Chain

Synthesis and Characterizations of Macrocyclic Cr(III) and Co(III) 1-Ethynyl Naphthalene and 9-Ethynyl Anthracene Complexes: An Investigation of Structural and Spectroscopic Properties

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