Synthesis, Characterization and Properties of Expanded Pyriporphyrins: A New Family of Alkylidenyl Porphyrin Homologues Bearing <i>meso</i>‐Exocyclic Double Bonds

Abebayehu, Abeje; Dutta, Ranjan; Lee, Changhee

doi:10.1002/chem.201602136

Cited by 15 publications

(10 citation statements)

References 47 publications

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“…2,6-pyridinedicarboxaldehyde; 2,3,5,6-tetramethyl-1,4- bis (trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene ( F ), 2,5-dimethyl-1,4-bis(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene ( G ) or 1,1′- bis (trimethylsilyl)-1,1′-dihydro-4,4′-bipyridine ( H ); and [( Mes Nacnac)MgMg( Mes Nacnac)] (where Mes Nacnac = [(2,4,6-Mes-C 6 H 3 -NCMe) 2 CH] − ) were prepared according to reported literature procedures. H 2 Mes,Ph L was prepared according to a modified literature procedure − and has been recently reported by Milsmann et al in full detail .…”

Section: Methodsmentioning

confidence: 99%

Bismuth Pyridine Dipyrrolide Complexes: a Transient Bi(II) Species Which Ring Opens Cyclic Ethers

Turner

2019

Inorg. Chem.

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A family of group 15 M III pyridine dipyrrolide complexes has been prepared and fully characterized; the reduction of these complexes was investigated with traditional strong metal reductants, which led either to over-reduction in the case of Mg and Zn or to ligand redistribution and "ate" complex formation when KC 8 was used. However, by utilizing organosilanes as soluble reductants, the ring opening and two electron reduction of thf solvent was observed with concomitant formation of Bi−C and Si−O bonds; this is an example of a main group complex that is capable of ring opening a cyclic ether in the absence of additional metal reducing agents. The proposed Bi II intermediate in this mechanism could be trapped using the stable organic radical TEMPO.

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Section: Methodsmentioning

confidence: 99%

Bismuth Pyridine Dipyrrolide Complexes: a Transient Bi(II) Species Which Ring Opens Cyclic Ethers

Turner

2019

Inorg. Chem.

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“…exhibits novel physico‐chemical properties , , , . Another interesting modification of porphyrins/expanded porphyrins is to replace one or more five membered pyrrole rings with six membered heterocycles such as pyridine and the resulted pyridine containing porphyrinoids or pyriporphyrinoids would be expected to possesses unusual and different properties from regular pyrrole containing porphyrinoids , . A perusal of literature revealed that Berlin and Breitmaier in 1994 reported the first example of pyridine containing porphyrinoids and ever since several interesting pyridine incorporated porphyrinoids that includes regular,, , , , contracted, expanded, , , and heteroporphyrinoids were reported.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Expanded Hetero 2,6‐Pyrihexaphyrins

et al. 2020

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New examples of expanded hetero 2,6‐pyrihexaphyrins 2–6 were synthesized in 12–18 % yields by condensing one equivalent of [10,10'‐bis(p‐tert‐butylphenyl)hydroxymethyl]‐1,3‐bis(2‐thienyl)‐pyridine diol with five different tripyrranes, under mild acid catalyzed conditions. The formation of 2,6‐pyrihexaphyrins 2–6 was confirmed by corresponding molecular ion peak in HR‐MS and were thoroughly characterized by 1D and 2D NMR spectroscopy, absorption, electrochemical and DFT/TD‐DFT studies. In 1H NMR, the proton resonances were either upfield or downfield shifted as the nature of one of the core heterocycles was varied from pyrrole to furan, thiophene, selenophene, and tellurophene indicating that the electronic properties of the macrocycle were altered by changing the core heterocycle. The NMR studies indicated that the macrocycles were nonaromatic in nature and absorption spectra of 2,6‐pyrihexaphyrins 2–6 showed one broad absorption band in the region of 600–1000 nm and two relatively sharp bands in the region of 350–500 nm. The aza analogue 2 showed considerable red shift in the absorption bands compared to other hetero 2,6‐pyrihexaphyrins 3–6. Upon protonation of the macrocycles, the resulting protonated macrocycles 2.H22+‐6.H22+ exhibits bathochromically shifted absorption bands. The redox studies indicated that the 2,6‐pyrihexaphyrins 2–6 are electron deficient and DFT studies supported the distortion and nonaromatic nature of the macrocycles.

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“…Most expanded porphyrins rely on increasing the number of pyrrolic building blocks linked either directly via α–α linkages or through one C atom, such as the classic sapphyrin, , hexaphyrin H 2 1 , − octaphyrin H 4 2 , − or even larger architectures (Figure ). , Nonpyrrolic heterocycles (e.g., thiophene, furan, pyridine, or pyrazole) ,− or conjugated spacers such as phenylene or ferrocene may be incorporated into the macrocycle, illustrating the broad diversity of molecules classified as expanded porphyrins.…”

Section: Introductionmentioning

confidence: 99%

Siamese-Twin Porphyrin Goes Platinum: Group 10 Monometallic, Homobimetallic, and Heterobimetallic Complexes

et al. 2020

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A series of PtII-based monometallic (H 2 PtL), homobimetallic (Pt 2 L), and heterobimetallic (NiPtL and PdPtL) group 10 complexes of the previously established expanded twin porphyrin (H 4 L) were prepared. Structural characterization of the bimetallic PtII series (Pt 2 L, NiPtL, and PdPtL) revealed their similar general structures, with slight differences correlated to the ion size. An improvement of the metal-ion insertion process also allowed efficient preparation of the known Pd 2 L complex, and the novel heterobimetallic NiPdL complex was also structurally characterized. UV–vis spectroscopy, NMR spectroscopy, magnetic circular dichroism (MCD), and (spectro)electrochemistry were used to characterize the complexes; the electronic properties followed largely established lines for metal complexes of the twin porphyrin, except that the PtII-based systems exhibited more complex UV–vis spectral signatures. MCD spectra accompanied by density functional theory (DFT)/time-dependent DFT computations (TDDFT) rationalize the origins of the optical features of the twin porphyrin. The presence of the nonplanar, nonaromatic macrocyclic π system with conjugation pathways confined to each half of the molecule could be visualized. Significant pyrazole(π) → pyrrole(π*) charge-transfer character was predicted for several transitions in the visible region. This study adds to our fundamental understanding of the formation, structure, and electronic structure of bimetallic complexes of this class of expanded metalloporphyrins containing nonpyrrolic moieties.

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Synthesis, Characterization and Properties of Expanded Pyriporphyrins: A New Family of Alkylidenyl Porphyrin Homologues Bearing meso‐Exocyclic Double Bonds

Cited by 15 publications

References 47 publications

Bismuth Pyridine Dipyrrolide Complexes: a Transient Bi(II) Species Which Ring Opens Cyclic Ethers

Bismuth Pyridine Dipyrrolide Complexes: a Transient Bi(II) Species Which Ring Opens Cyclic Ethers

Synthesis of Expanded Hetero 2,6‐Pyrihexaphyrins

Siamese-Twin Porphyrin Goes Platinum: Group 10 Monometallic, Homobimetallic, and Heterobimetallic Complexes

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