Chemical, spectral, structural, and charge transport properties of the "molecular metals" produced by iodination of nickel phthalocyanine

Schramm, Charles J.; Scaringe, Raymond P.; Stojaković, Djordje; Hoffman, Brian M.; Ibers, James A.; Marks, Tobin J.

doi:10.1021/ja00542a008

Cited by 405 publications

(165 citation statements)

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“…Treatment of metal and free base phthalocyanines (M = Ni, Cu, Zn, Pt, H2) with oxidants such as iodine results in a change from the normal X crystal phase of the phthalocyanine to a stacked cofacial structure with disordered polyiodide anions residing in the channels surrounding the conducting stacks (10,11). These structural changes are accompanied by a dramatic increase in the electrical conductivity.…”

mentioning

confidence: 99%

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

Collman

McDevitt

Yee

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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The synthesis and characterization of pyrazine-bridged polymers of iron(I/IlI), ruthenium(U/Il), and osmium(H/III) octaethylporphyrin (dubbed "shish-kebab" polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polym,ers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway. Unlike most of the previously reported porphyrinic molecular metals in which the conduction electrons are macrocyclicbased, electron transport in these materials proceeds exclusively along the metal-pyrazine backbone. pressure (3, 4). Considerable effort has been directed toward the synthesis of superconductors with higher critical temperatures. The possibility that high-temperature organic superconductors could exist came initially from a suggestion by Little in 1964 that excitonic superconductors could be fabricated from a highly conjugated organic polymer to which dye molecules were covalently bound at regular intervals (5). It was proposed that electrostatic interactions between the conducting electrons and the ir electrons on the polarizable dyes might result in the same type of phenomenon that is responsible for the low-temperature superconductivity found in some metals and metal alloys. A key feature of these hypothetical polymers is that their superconducting critical temperature is predicted to be well above those of the conventional phonon superconductors.Since the introduction of Little's theory, tremendous progress has been made in the study of organic metals and low-temperature organic superconductors. However, virtudlly no evidence has been found for the existence of excitonic superconductivity. The lack of progress in this area may be ascribed to the stringent requirements of the theory (6) and to the extreme difficulties associated with the synthesis of the proposed materials. Recently, a few reports of metastable, diamagnetic anomalies at temperatures well above the Bardeen-Cooper-Schrieffer limit have further stimulated speculation that some kind of high-temperature superconducting state might exist (ref. 7 and references therein).Considerable interest has been directed toward the synthesis and characterization of conducting molecular crystals formed from inorganic coordination complexes. Although no superconductors have been prepared from coordination complexes to date, these materials form an interesting set of molecular conductors. Conductive molecular crystals can be placed into two categories. The first and most widely known is typified by the tetracyanoplatinate complexes (Krogman salts) (8, 9). These systems are characterized by electron transport properties resulting from extended metal-metal overlap in the core of stacked square planar complexes. The ancillary ligands appear to play little role in the conduction process. The second category contains those systems in which a macrocycle, and not the bound metal, supports the conduction.Much o...

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confidence: 99%

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

Collman

McDevitt

Yee

et al. 1986

Proc. Natl. Acad. Sci. U.S.A.

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“…This delocalisation and the interactions of the p-electron with the central metal atom determine the redox properties of these complexes [1,2]. These in turn led to the study of semi-conductivity, photoconductivity, photochemical reactions, photosynthetic and electrocatalytical activities, etc.…”

Section: Metallophthalocyaninesmentioning

confidence: 99%

Ir and Uv-Visible Spectra of Iron(ii) Phthalocyanine Complexes With Phosphine or Phosphite

Zanguina

Bayo-Bangoura

Bayo

et al. 2002

Bull. Chem. Soc. Eth.

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ABSTRACT.We have prepared and studied by vibrational and electronic spectrometry of a series of ferrophthalocyanine complexes with phosphine or phosphite axial ligands [PMe3, P(OMe)3, PPh3, P(OPh)3, PPh(OMe)3 and POH(OEt)2]. With PMe3, P(OMe)3 as ligands, only hexacoordinated complexes are obtained but with PPh3, P(OPh)3 and POH(OEt)2 as ligands, the coordination number depends on the FePc:ligand ratio in the reaction mixture. In the ratio 1:1 the complexes thus formed are pentacoordinated and in the ratio 1:2 hexacoordinated complexes are obtained. In the electronic spectra of hexacoordinated complexes, two charge-transfer transition bands, one at ~375 nm and the other at ~421 nm can be observed. We attribute the band at 375 nm to charge-transfer from axial ligand to macrocycle (CT Lax ® Pc) and the band at 421 nm to charge-transfer from metal to axial ligand (CT Fe ® Lax). In the IR spectra, the position of the nFeN4 band is linked to the coordination number; in the spectra of pentacoordinated complexes, its frequency is almost the same as that in the FePc spectrum but in hexacoordinated complexes, it moves to high frequencies.

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“…IOp7 Ycm. This enhancement is rather low relative to PcNi (a = 10-* S/cm) [22] and PcNiI, (B = 7.10-l S/cm)[221. The doped product PcReNI, (3a) contains about 12% iodine (x = 0.8).…”

Section: Cnmentioning

confidence: 99%

Synthesis and Characterization of Nitrido(tetra‐tert‐butylphthalocyaninato)‐ rhenium(V) and Nitrido(phthalocyaninato)rhenium(V)

Ziener

Hanack

1994

Chem. Ber.

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Key Words: Rhenium(V), nitrido(tetra-tert-butylphtha1ocyaninato)-/ Rhenium(V), nitrido(phthalocyaninat0)-/ Phthalocyaninato complexes 4-tert-Butylphthalodinitrile (1) reacts with ammonium perrhenate, NH4Re04, to yield nitrido(tetra-tert-butylphthalocyaninato)rhenium(V), ( t B~)~p c R e N (2), which is characterized by IR, UV/Vis, CV, MS, 'H and I3C NMR, and elemental analysis. It shows good solubility in common organic solvents. In solution 2 is assumed to be monomeric whereas in the solid state also dimers or higher aggregates are present. From the NMR spectra it is concluded that different constitutional isomers of 2 are formed but not in the expected ratio of a statistical distribution. By analogy with 2, the already known nitrido(phthalocyaninato)rhenium(V), PcReN (3), is prepared for comparison.Our ongoing work is concerned with bridged macrocyclic phthalocyaninato transition metal complexes [PcM(L)], (with M e.g. Fe, Ru, OS) that contain the ligands L as bidentate linear organic molecules, e. g. pyz (pyrazine), tz (tetrazine), dib (1,4-diisocyanobenzene), leading to a comparable large distance (600-1200 pm) between the cofacial Pc rings in the polymer [']. A smaller distance of the macrocycles in such polymers could be advantageous, e.g. for the electrical properties. Oxygen as the bridging ligand which could lead to a smaller distance between the macrocyclic units is only known for one example in the hemiporphyrazine (Hp) compound [HpFeO], with Fetrv as the central metal ion[2]. PcFe does not form an equivalent compound but p-0x0 dimers ( P C F~)~O [~] .Therefore we investigated the possibility of using nitrogen as a potential candidate for a bridging ligand. In this paper we report on the synthesis of the first soluble nitrido(phtha1ocyaninato)rhenium complex, nitrido-(tetra-tert-butylphthalocyaninato)rhenium, (tBu),PcReN (2). For comparison the synthesis of PcReN (3) was repeatedL91. Up to now the bonding conditions of the axial Re-N bond in both 2 and 3 are not completely clear. Asymmetric bridging as known for example in K2ReN(CN),. H20[121 cannot be excluded. Results and DiscussionNitrido(tetra-tert-butylphthalocyaninato)rhenium(V), (tBu),PcReN (2), was synthesized by reaction of 4-tert-b~-tylphthalodinitrile (1) with ammonium perrhenate (see Scheme 1). Compound 2 was purified by column chromatography; its yield is low compared to that of PcReN (3) (see below).The IR spectrum of 2 is very similar to those of other tetra-tert-butyl-substituted phthalocyaninato metal complexes such as (tBu),P~Co ['~l and (tB~)~PcFe['~l. In the region between 950 and 1000 cm-' a band of low intensity is found in all these IR spectra. In the spectrum of 2 the intensity of this band at 978 cm-' is somewhat increased. This Chew.

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Chemical, spectral, structural, and charge transport properties of the "molecular metals" produced by iodination of nickel phthalocyanine

Cited by 405 publications

References 1 publication

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

Ir and Uv-Visible Spectra of Iron(ii) Phthalocyanine Complexes With Phosphine or Phosphite

Synthesis and Characterization of Nitrido(tetra‐tert‐butylphthalocyaninato)‐ rhenium(V) and Nitrido(phthalocyaninato)rhenium(V)

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