The direction of excitation energy migration is reversed in a system composed of {Ru(bpy)(2)}-{pyridylporphyrin}(2) by the addition of a Zn(2+) ion. The Zn(2+) system shows an excitation-wavelength dependent emission.

Carbonyl-coordinated ruthenium(II) and osmium(II) porphyrin dimers bridged with aza ligands, [{M(por)(CO)}(2)](BL), (M = Ru-II, Os-II; por = ttp (5,10,15,20-tetra-p-tolylporphyrinato dianion), oep (2,3,7,8,12,13,17,18-octaethylporphyrinato dianion); BL = pz (pyrazine), bpy (4,4'-bipyridine), dabco (1,4-diazabicyclo [2,2,2] octane)), were prepared and characterized, and their structures were determined by using single-crystal X-ray crystallography. The metal-metal distances of the pz-, bpy-, and dabco-bridged dimers in [{M(por)(CO)}(2)(BL)] were about 7.1-7.3, 11.5, and 7.3-7.4 angstrom, respectively. From electrochemical measurements, the first oxidation waves of the ruthenium and osmium porphyrin dimers with the pz and dabco, except the Ru-oep systems, were split, although the first oxidation in the Ru complexes occurs at the porphyrin rings and in the Os complexes occurs at the metal centers. The extent of the potential splits at the first oxidation processes, which reflects magnitude of the intramolecular redox interactions, was in the orders: up > oep and Os (metal oxidation) > Ru (ring oxidation), and dabco >= pz >> bpy.

5-(3-Pyridyl)porphyrinatoruthenium(IT) tetramers, [{Ru(3-PyT(3)porph)(CO)}(4)](1), [(Ru(3-PytB(3)PorPh)(CO)}(4)] (2), [{Ru(3-PyHex(3)porph)(CO)}(4)] (3), and [{Ru(3-PytB(3)porph)(py)}(4)] (4) were prepared. The structures of the isolated tetramers were determined to be rhombic shaped with two chemically nonequivalent porphyrinatoruthenium(II) subunits by H-1 NMR, IR, and ESI-MS measurements. The tetramers were stable in benzene at 70 degrees C. However, the tetramers reacted with a large excess of pyridine to give two geometrical isomers of porphyrinatoruthenium(II) in dichloromethane at room temperature as observed by 1 H NMR spectrometry. UV-vis spectra of the tetramers showed splitting or broadening of the Soret band due to excitonic interactions. Stepwise oxidations of the porphyrin rings or the ruthenium ions in the cyclic tetramer skeleton were observed in cyclic voltammograms.

New hybrid complexes of polypyridyl ruthenium and pyridylporphyrins have been prepared by the coordination of pyridyl nitrogens to the ruthenium centers. A 1:4 hybrid complex, [{Ru(bpy)(trpy)}4(mu4-H2Py4P)]8+ ([1]8+) (bpy = 2,2'-bipyridine; trpy = 2,2':6',2"-terpyridine; H2Py4P = 5,10,15,20-tetra(4-pyridyl)porphyrin), has been characterized by the single-crystal X-ray diffraction method. A 1:1 complex, [{Ru(bpy)(trpy)}(H2PyT3P)]2+ ([2]2+) (H2PyT3P = 5-(4-pyridyl)tritolylporphyrin) has also been prepared. The Soret band of the porphyrin ring shifts to longer wavelength with some broadening, the extent of the shift being larger for [1]8+. Cyclic voltammograms of the two complexes show simple overlap of the component redox waves. The complexes are weakly emissive at room temperature, which becomes stronger at lower temperatures. While [1]8+ at >140 K and [2]2+ at 77-280 K show only porphyrin fluorescence, [1]8+ at <140 K shows ruthenium and porphyrin phosphorescence, in addition to the porphyrin fluorescence.

Aiming at construction of robust molecular architectures having an active center surrounded by stable walls, a box-shaped cobalt (II)-rhodium (III) pentaporphyrin [Co(tpyp)][Rh(tpp)Cl](4) (2) (tpyp = 5,10,15,20-tetrapyridylporphyrinato dianion, tpp = 5,10,15,20-tetraphenylporphyrinato dianion) was newly synthesized via coordination bonds. The cobalt(II) center of the complex 2 reacts reversibly with O-2 to give a corresponding dioxygen complex of [Co(tpyp)(py)(O-2)][Rh(tpp)Cl](4) (2(py)(O-2)) at low temperatures in dichloromethane-containing pyridine.

Rhodium(III) porphyrin complexes, [Rh(4-PyT(3)P)Cl](4) (1) and [Rh(2-PytB(3)P)Cl](2) (2) (4-PyT(3)P = 5-(4-pyridyl)-10,15,20-tritolylporphyrinato dianion, 2-PytB(3)P = 5-(2-pyridyl)-10,15,20-tri(4-tert-butyl)phenylporphyrinato dianion), were self-assembled and characterized by (1)H nuclear magnetic resonance spectroscopy, infrared spectroscopy, and electron spray ionization-mass spectroscopy methods. The spectroscopic results certified that the rhodium porphyrin complexes 1 and 2 have a cyclic tetrameric structure and a cofacial dimeric structure, respectively. The X-ray structure analysis of 1 confirmed the cyclic structure of the complex. The Soret bands of both oligomers were significantly broadened by excitonic interactions between the porphyrin units, compared to those observed for a corresponding analogue of Rh(TTP)(Py)Cl (TTP = 5,10,15,20-tetratolylporphyrinato dianion, Py = pyridine). Stepwise oxidation of the porphyrin rings in the oligomers was observed by cyclic voltammetry. The oligomers 1 and 2 are very stable in solution, and they slowly undergo reactions with pyridine to give corresponding monomer complexes only at high temperatures (approximately 80 degrees C).

Four novel Fe-Ru mixed-metal hexaporphyrins having an Fe(III)-O-Fe(III) porphyrin dimer unit at the center and four surrounding ruthenium(II) porphyrin units were synthesized, characterized, and structurally analyzed by X-ray crystallography.

The synthesis and properties of novel anthracene-bridged porphyrin dimers having an oxomolybdenum(V) porphyrin unit, H(2)(DPA)[Mo(V)O(OMe)] (1) and (DPA)[Mo(V)O(OMe)][Zn(II)(MeOH)] (2), and the relevant monomer porphyrin complexes Mo(V)O(MPP)OMe (3) and Zn(II)(MPP) (4) are presented. An oxomolybdenum(V) unit was introduced into one of the two porphyrins in DPA to give 1, which has a free-base porphyrin unit. By introducing a zinc(II) ion to the free-base part, a mixed-metal complex of 2 was prepared and isolated. The structure of 2 was analyzed by X-ray crystallography (2.(7)/(6)CH(2)Cl(2), triclinic, P(-)1 (no. 2), a = 15.2854(12) A, b = 19.9640(15) A, c = 13.6915(12) A, alpha = 90.968(3), beta = 113.108(4), gamma = 96.501(4), Z = 2, R1 = 9.9, wR2 = 19.2). The structure of 2 demonstrated that a methanol is stably coordinated to the Zn(II) ion with the aid of a hydrogen bond to the methoxo ligand on the Mo(V) ion in the binding pocket of DPA. The electrochemical measurements of 2 suggested that the methanol was kept in the pocket of DPA in solution even at the reduced state of the molybdenum ion.

Ein Porphyrinball: Sechs oktaedrisch angeordnete Porphyrine erhält man durch Koordination von 5-(4-Pyridyl)-10,15,20-tritolylporphyrinen (H2PyT3Ps) an einen Octa(μ3-S/μ3-Se)hexarhenium(III)-Kern. Wie eine Röntgenstrukturanalyse von [Re6(μ3-S)8(H2PyT3P)6](SbF6)2 zeigt, sind die sechs Porphyrinliganden S6-symmetrisch angeordnet (siehe Bild).

The one-electron oxidation of MoVIO(tmp)(O2) gave a product with reduced metal ion, oxomolybdenum(V) tetramesitylporphyrin, by releasing O2.

The molecular structure of a reversible oxygen carrier, MoVIO(tmp)(O2) has been characterized by X-ray crystallography. Oxo and dioxygen ligands are actually coordinated with cis conformation, which leads to a saddle-like distortion of the porphyrin ring. The result of 2D ROESY shows the distortion of the porphyrin ring is retained in solution.

Reversibility in the formation reaction of a series of the oxo(peroxo)porphyrinatomolybdenums, [MoVIO(tmp)(O2)] 1, [MoVIO(tdcpp)(O2)] 2, [MoVIO(ttp)(O2)] 3, [MoVIO(tdmpp)(O2)] 4, and [MoVIO(tpp)(O2)] 5, was studied. In these dioxygen complexes with various porphyrin rings, two complexes, 2 and 4, were newly prepared by the solid-state reactions of corresponding Mo(IV) complexes with O2. All the complexes were characterized by IR, 1H NMR, and UV-vis spectroscopic measurements. In the reaction of O2 with [MoIVO(tdcpp)] 2r, which has bulky substituents with an electron-withdrawal character, the association rate constant was determined to be 1.2 × 10-2 dm3 mol-1 s-1 in toluene at 20 °C. The value of the rate constant is about one thirtieth of that for [MoIVO(tmp)] 1r, which also has bulky substituents. The result indicates that the electronic effects of the porphyrin rings, which reflect on the redox potentials of the central molybdenum ion, are important in determining kinetic and thermodynamic stability of ...

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Various porphyrin oligomers assembled from free-base pyridylporphyrins and metallopyridylporphyrins are reviewed. In the oligomers, metal ions such as zinc, ruthenium, and osmium ions are incorporated into pyridylporphyrin units. These can act simultaneously as both axial or bridging ligands as well as functional groups. The oligomers can be divided into two groups: discrete metallopyridylporphyrin arrays and infinite networks. The latter is briefly summarized.

Four atropisomers of a molybdenum porphyrin dioxygen complex, (MoO)-O-VI(TNP)(O-2) 1, having naphthyl groups at the meso positions of the porphyrin ring were separated by column chromatography and characterized as dioxygen complexes by general spectroscopic methods. Although the structures of the atropisomers could not be determined explicitly, the kinetic measurements of the dioxygenation of (MoO)-O-IV(TNP) with O-2 in solution revealed that the association rate constants were significantly affected by the orientation of naphthyl groups with the values of (0.48-1.3) x 10(-1) M-1 s(-1) in toluene at 20 degreesC.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTCoupling of Ground-State Molecular Vibrations to Low-Energy Electronic Transition of Ruthenium(III,II) Porphyrin DimersTaira Imamura, Kenji Funatsu, Shen Ye, Yoshiyuki Morioka, Kohei Uosaki, and Yoichi SasakiView Author Information Division of Chemistry, Graduate School of Science Hokkaido University, Sapporo 060-0810, Japan Department of Chemistry, Faculty of Science Saitama University, Urawa 338-8570, Japan Cite this: J. Am. Chem. Soc. 2000, 122, 37, 9032–9033Publication Date (Web):August 31, 2000Publication History Received8 December 1999Published online31 August 2000Published inissue 1 September 2000https://pubs.acs.org/doi/10.1021/ja994297ghttps://doi.org/10.1021/ja994297grapid-communicationACS PublicationsCopyright © 2000 American Chemical SocietyRequest reuse permissionsArticle Views260Altmetric-Citations14LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Energy levels,Infrared light,Oligomers,Oscillation,Pyrroles Get e-Alerts

A novel porphyrin octamer with a ruthenium porphyrin tetrameric core was synthesized and characterized.

Molybdenum porphyrin dioxygen complexes without bulky substituents, (MoO)-O-VI(ttp)(O-2) 1 and (MoO)-O-VI(tpp)(O-2) 2 were successfully prepared by the direct dioxygenation of corresponding oxomolybdenum(IV) porphyrin complexes in the solid state.