Metallkomplexe mit tetrapyrrol-liganden, VI (1)

Buchler, Johann W.; Rohbock, Klaus

doi:10.1016/0020-1650(72)80196-x

Cited by 82 publications

(27 citation statements)

References 6 publications

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“…Complex I was synthesized using procedure [13]: meso -tetraphenylporphyrin ( H 2 TPP ) (0.1 g, 0.16 mmol) was boiled with åÓé 3 (0.076 g, 0.53 mmol) in 0.8 g of phenol at 454 K for 4 h. The procedure was finished when the electronic absorption spectrum of a sample of the reaction mixture dissolved in chloroform did not contain absorption band typical of H 2 TPP ( λ max , nm: 648.0, 592.0, 551.0, 516.0, 485.0, 420.0). In order to isolate the obtained complex, phenol was distilled off in vacuum, the residue was dissolved in a minimum vol-ume of CHCl 3 and twice chromatographed on Al 2 O 3 with the use of chloroform.…”

Section: Methodsmentioning

confidence: 99%

Thermodynamics and Kinetics of Reaction of (Oxo)(hydroxo)molybdenumtetraphenylporphyrin with Pyridine

2005

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The reaction of meso -tetraphenylporphyrin with Mo(VI) oxide in boiling phenol resulted in a stable complex O=Mo(OH)TPP. Thermodynamics and kinetics of the reaction between (oxo)(hydroxo)molybdenumtetraphenyporphyrin with pyridine in toluene were studied by spectrophotometric method. This reaction was found to occur in three equilibrium elementary stages: replacement of OHby Py ( K 1 = 9.1 × 10 3 l/mol, k 1 = 5.25 s -1 mol -1 l), the formation of dication (dipyridine)(hydroxo)molybdenumtetraphenylporphyrin as a result of cleavage of a double bond Mo=O ( K 2 = 39.3 l/mol, k 2 = 1.83 × 10 -2 s -1 mol -1 l), and the formation of cationic complex [ Mo ( Py ) 3 TPP ] 3+ · 3 OH -( K 3 = 1.0 l/mol, k 3 = 1.19 × 10 -3 s -1 mol -1 l).

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Section: Methodsmentioning

confidence: 99%

Thermodynamics and Kinetics of Reaction of (Oxo)(hydroxo)molybdenumtetraphenylporphyrin with Pyridine

2005

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“…12 5,10,15,20 Tetraphenyl 21H,23H porphinemolyb denum(V) hydroxide oxide O=Mo(OH)TPP was synthe sized by complexation of porphyrin with Mo VI oxide. 31 The yield was 60%. The electronic absorption spectrum in chloroform (λ max /nm (logε): 620.0 (2.94), 584.0 (2.92), 456.0 (3.78)) corresponds to the published data.…”

Section: Complexes With Cr III Mo V and W Vmentioning

confidence: 98%

“…5,10,15,20 Tetraphenyl 21H,23H porphinechro mium(III) acetate (AcO)CrTPP was synthesized by the complexation reaction according to a known procedure. 31 The yield of the complex was 40%. The electronic ab sorption spectrum of (AcO)CrTPP (λ max /nm (logε) in , 358 (4.18)) corresponds to that described earlier.…”

Section: Complexes With Cr III Mo V and W Vmentioning

confidence: 99%

Metalloporphyrin receptors for bases

et al. 2007

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The review summarizes data on the reversible addition of inorganic and organic biologi cally active bases at the coordination sites of mixed complexes containing the porphyrin dianion as one of ligands. An analysis of the thermodynamic parameters revealed new receptors for small cyclic molecules holding promise for analytical purposes and sensorics.Porphyrins (H 2 P) form simple and mixed coordina tion compounds (MP) with metal cations. 1-3 Simple complexes can have the cation : ligand composition 2 : 1, 1 : 1, 1 : 2, or 2 : 3. Complexes of the latter two composi tions have a sandwich structure. 4,5 The coordination spheres of mixed complexes contain, in addition to por phyrin, molecular, acido, or chelating ligands. Although sandwich complexes with a 2 : 3 stoichiometry belong to simple coordination compounds, each metal atom in these complexes is bound to two structurally different macro cyclic ligands (X ray diffraction data 6 ), viz., to the central planar ligand and the terminal dish shaped ligand.Among mixed complexes, complexes with aromatic macrocyclic ligands are distinguished by the nearly planar arrangement of the donor and other atoms of the macro cyclic ligand, a high charge density at the bonds in the coordinated aromatic ligand, and the delocalized elec tronic state of the latter. In other classes of mixed com plexes, cyclic ligands can contain only double and triple bonds or heteroatoms with several lone electron pairs as sterically rigid units, whereas the macrocycle in metallo porphyrins is rigid by itself. In other words, one of the ligands in mixed metalloporphyrins is characterized by the maximum steric rigidity. Upon coordination, the metal cation cannot impose stoichiometric constraints on this ligand corresponding to the optimal polyhedron of the complex. Hence, the overall coordination sphere of mixed porphyrin containing complexes is rather specific. Al though the specificity of the replacement of small (non macrocyclic) acido ligands in mixed porphyrin contain ing complexes of highly charged metal cations is well known, these reactions have received little quantitative study.Metalloporphyrins, in which the maximum possible coordination number of the metal cation is not achieved, can bind bases and form mixed coordination compounds.Until recently, these additional ligands in the coordina tion sphere have been commonly called extra ligands. 3,7 However, it is already evident that additional coordina tion processes is a special case of reactions of MP with bases. Nowadays, the coordination or replacement reac tions of ligands involving porphyrin complexes of highly charged metal cations (z > 3) are of considerable interest for coordination and applied chemistry, because these complexes not only have vacancies in the first coordina tion sphere but are also coordinatively unsaturated and are characterized by a high effective positive charge of the central atom due to high diversity of possible coordina tion polyhedra.In the overwhelming majority of cases, the coordina tion of inorganic and o...

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“…Furthermore, porphyrins and their structural analogues are used in broad technological applications such as electrophotographic photoreceptors, air deodorant, pigment preparations and photodynamic therapy 3 and in development of molecular electronic devices used in memory or logic applications 4 . Over the past few years, the d 0 transition-metal porphyrins containing Sc(III), Ti(IV), Zr(IV), Hf(IV), Nb(V), and Ta(V) have been synthesized and characterized [5][6][7][8][9] . This has been mainly due to the use of these compounds in catalysis, photodynamic therapy of cancer cell 10 , as materials with novel electrical properties 11 and as biomimetic model systems of primary processes of natural photosynthesis 12 and also due to their strong affinities for DNA and potential nuclease activity 13 .…”

mentioning

confidence: 99%