Thallium porphyrin complex

The thallium complexes show somewhat different electrochemical behavior, and reversible oxidations are observed for both n-alkyl and n-aryl thallium porphyrins, indicating that the oxidized complexes have a more stable metal—carbon bond than the gallium or indium analogs. Spectroelectrochemistry revealed that the first oxidation is porphyrin ring-centered. The first reduction is reversible and ring... 

Thallium complexes amidines, 205 phthalocyanines, 863 porphyrins, 821 triazines, 205 Thallium(I) complexes... 

Thalliuin(III) trifluoroacetate will also eliminate trifluoroacetic acid in reactions with compounds containing N—H bonds 40, 240). Thus, brief treatment of octaethylporphyrin in CHgCla and tetrahydrofuran with an excess of T1(02CCF3)3 followed by chromatography on deactivated alumina affords the complex shown in Fig. 10, This was the first unambiguous characterization of a thallium(III) porphyrin 240). 

Thallium complexes amidines, 205 phthalocyanines, 863 porphyrins, 821 triazines, 205 Thallium(I) complexes hexafluoroacetylacetone, 372 Thallium III) complexes carboxylic acids reactions, 443 1,3-diketones synthesis, 377... 

For In(Por)F complexes, the H-umr data indicate that a five-coordinate coordination sphere can be proposed. Similar results have been obtained for the series of thallium (HI) porphyrins. The meso and pyrrole protons give a doublet for Tl(OEP)F and T1(TPP)F. The same spectral morphology is observed for Tl(Por)Cl, and results in a coupling between the... 

Thallium(III) acetate reacts with alkenes to give 1,2-diol derivatives (see p. 128) while thallium(III) nitrate leads mostly to rearranged carbonyl compounds via organothallium compounds (E.C. Taylor, 1970, 1976 R.J. Ouelette, 1973 W. Rotermund, 1975 R. Criegee, 1979). Very useful reactions in complex syntheses have been those with olefins and ketones (see p. 136) containing conjugated aromatic substituents, e.g. porphyrins (G. W. Kenner, 1973 K.M. Smith, 1975). 

Porphyrin, octaethyl-, thallium chloride complex cyclic voltammetry, 4, 399 <73JA5140)... 

Aluminum, Gallium, Indium, and Thallium Porphyrin Complexes, M(Por)R... 

Overall, the UV-visible, NMR, and electrochemical data for the range of O -bonded complexes of gallium, indium, and thallium porphyrins show that there is a trend from pure a -bonded character of the M—C bond in the alkyl complexes to the much more ionic character observed for the fluorophenyl and acetylide complexes. These more ionic complexes show NMR and UV-visible characteristics more like those of the ionic M(Por)Cl or M(Por)C104 complexes. ... 

Most of the studies on organo-gallium, indium, and thallium porphyrin complexes have focused on synthesis and properties of the complexes, and rather little attention has been devoted to reaction chemistry. Two areas which have received some attention are the insertion of small molecules (SO2 or CO2) into the metal—carbon bonds and photochemical metal—carbon bond cleavage. The... 

Halide complexes of this group react with carbanions to form stable alkylmetalloporphyrins.27 The thallium atom is significantly displaced (0.98 A) from the N4 plane with a large T1—N,, distance (2.29 A) in Tl(TPP)Me, formed by the reaction of H2TPP and MeTl(OCOMe)2 (Scheme 5). Monovalent thallium porphyrin complexes are also known.17 They can be prepared by treating a porphyrin with thallium(I) ethoxide in THF.29 Unlike the other Group IIIB metalloporphyrins, [Tl i Por) is easily hydrolyzed. 

I a porphyrins are salts with two M+ counterions II a and II b porphyrins contain metals in their +2 oxidation states Illb porphyrins in the +3 state. All complexes are diamagnetic and produce normal electronic spectra. Most of them fluoresce. For thallium a labile green TPP complex has been described (696, 646, 483, 458), which could be the TI21 salt [.Rothemund (153)]. A report on Tl11 porphyrins (153) is probably in error, because in air only Tlni porphyrins have been found in later investiga-... 

The thallium (III) complex [T1 (OETNP)Cl)] also crystallised with two crystallographically independent molecules. Surprisingly, the structure shows a much smaller degree of conformational distortion than observed in Ni(OETNP), H2(OETNP) and other dodecasubstituted porphyrins (Fig. 21). While in the strongly distorted structures displacement of the Cp atoms are in the range 0.9 A-1.2 A, the two thallium derivatives show displacements of 0.3 and 0.17 A... 

The oxidative ring closure of a magnesium complex of porphyrin p-ketoesters (32a) onto the neighboring me.ro-position by iodine in methanol affords a meth-oxy phaeoporphyrin ester (33a) and provides a model for the biosynthesis of the isocyclic ring of chlorophyll. A more efficient process was the use of thallium... 

The electrochemistry of gallium, indium, and thallium porphyrins with o-bonded aryl and alkyl groups has been reported by Kadish and Guilard . Complexes of Ga(Por)(R), In(Por)(R) and Tl(Por)(R) are reversibly reduced by up to two single electron transfer additions. These electroreductions are shown in Eq. 12 and 13 where M = Ga, In, or Tl. 

The Group 13 porphyrins usually show similar electrochemical behavior upon going down the Periodic Table, although differences do exist in the stability of the oxidized and reduced forms of the compounds upon going from Al(III) to Tl(III). All complexes of the type (P)MX, where M = Al(III) [360], Ga(III) [355], In(III) [356], or Tl(III) [353], and P = TPP or OEP are oxidized at the porphyrin macrocycle to give ranion radicals and dianions upon reduction. The Tl(III) complexes undergo what appears in many cases to be a metal-centered two-electron reduction prior to demetallation [339],... 

Substrate resonances may also be affected by complexation to diamagnetic complexes, where the complexes possess ligands having a diamagnetic anisotropy [38]. Such compounds, e.g. chlorophyll or Ru" porphin show such effects. Here too the mutual interactions of the complexes themselves should be taken into account [39]. The thallium porphyrins cannot further complex and the aggregates are assumed to be formed from an electrostatic interaction between the porphyrin rings. 

OBu In] with metal hexacarbonyls gives the unusual cmnplexes [(CO)jMSn(p.-OBu ),InM(CO)3] (M=Mo,Cr) via initial coordination of the metal at the indium and tin sites . Two papers include both indium and thallium compounds. Thus, the preparation of [ CpM(CX>)3 3E] (MssMo,Cr,Es In,Tl) is described, extended Hiickel calculations indicating that the In-Mo bond is polar, and tire ic-bonding interaction is only weak . The synthesis and electrochemistry of the porphyrin (P) complexes [(P)ERe((X))s] is also described . Hnally one report describes the synthesis of phosphine substituted crown complexes containing a thallium-iridium bond. The nature of this interaction has been studied in some detail . 

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