Molecular stereochemistry of (.alpha.,.gamma.-dimethyl-.alpha.,.gamma.-dihydrooctaethylporphinato)oxotitanium(IV)

Dwyer, Patrick N.; Puppe, Lothar; Buchler, Johann W.; Scheidt, W. Robert

doi:10.1021/ic50150a008

Cited by 63 publications

(21 citation statements)

References 22 publications

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“…Selected structural data for the porphodimethenes are compiled in Table 2. In general, the structural characteristics are similar to those of known porphyrins [14] and porphodimethenes [36][37][38][39][40][41], the major distinction being somewhat larger mesodisplacements in the present porphodimethenes compared with those found in the literature, which are mainly of the 5,15-dialkyl-2,3,7,8,12,13,18,18-octaethylporphyrin type. There are some interesting differences in the conformation of the three porphodimethenes.…”

Section: Bearing Meso-ch-(c-spsupporting

confidence: 76%

“…This leads to a roof-type conformation with syn-axial orientation of the two tert-butyl groups at the sp 3 -hybridized meso-carbons (5 and 15). Such porphodimethene conformations have been described before by Buchler and co-workers [36][37][38][39][40][41]. Depending on the crystallization conditions, we were able to obtain single crystals for two unsolvated, triclinic modifications of Cu(II)14 and complexes of Zn(II)13 with either methanol or piperidine as axial ligands.…”

Section: Bearing Meso-ch-(c-spsupporting

confidence: 57%

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Synthesis, Reactivity and Structural Chemistry of 5,10,15,20-Tetraalkylporphyrins

Senge

Bischoff

Nelson

et al. 1999

J. Porphyrins Phthalocyanines

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The synthesis, reactivity and full characterization of a series of meso-tetraalkyl porphyrins and metalloporphyrins with R ≡ n-butyl (6), 2-methyl-propyl (7), isopropyl (8), l-ethyl-propyl (10) and tert-butyl (11) groups are reported. Derivatives of the last of these show considerably bathochromically shifted absorption bands and the crystal structure of Zn ( II )11(pyr) exhibits a severely ruffled macrocycle conformation. Systematic crystallographic studies of the porphyrins showed that the free base porphyrins with R ≡ n-butyl ( H 26), 2-methyl-propyl ( H 27) and 1-ethyl-propyl ( H 210) are planar. A larger conformational variety was found for the metal complexes. While most Ni ( II ) derivatives and Pd ( II )8 showed a ruffled macrocycle conformation with a degree of ruffling exceeding that of meso-unsubstituted porphyrins, both planar and non-planar forms were found for the related Cu ( II ) derivatives. The Zn ( II ) complexes of porphyrins with isopropyl or 1-ethyl-propyl exhibited conformations with variable degree of distortion. Together with comparative structures from the literature, this study provides experimental evidence that considerable conformational flexibility exists for meso-alkylporphyrins with substituents less bulky than tert-butyl groups.

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Section: Bearing Meso-ch-(c-spsupporting

confidence: 76%

Section: Bearing Meso-ch-(c-spsupporting

confidence: 57%

Synthesis, Reactivity and Structural Chemistry of 5,10,15,20-Tetraalkylporphyrins

Senge

Bischoff

Nelson

et al. 1999

J. Porphyrins Phthalocyanines

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“…The typical examples for the latter ones are the low-spin nickel(II) [4,13], chromium(III) [14,15], titanium(IV) [16] and manganese(III) porphyrins [17], as well as the copper(III) corrole [18], while their high-spin complexes (if it is possible) are usually planar. Fig.…”

Section: Figmentioning

confidence: 99%

Application of the electronic spectra of porphyrins for analytical purposes: The effects of metal ions and structural distortions

Valicsek

Horváth

2013

Microchemical Journal

122

118

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We investigated the UV-Vis absorption, singlet-1 and singlet-2 fluorescence, as well as the formation of several metalloporphyrins from equilibrial and kinetic aspects in aqueous solution. Among these complexes were numerous typical out-of-plane and several in-plane metalloporphyrins, and between the two categories, a few border-line cases. On the basis of our results, we have complemented the categorization introduced by Barnes and Dorough for the metalloporphyrins. According to our observations, also in metalloporphyrins, the distortion, i.e., the planarity or nonplanarity of the macrocycle, is basically responsible for the spectral characteristics, while the electronic structure of metal center is a secondary factor, with a considerable importance mainly in the in-plane complexes. The type of complexes can be spectrophotometrically determined on the basis of their UV-Vis absorption and fluorescence spectra. Beside the spectral and photophysical effects of metalation, also those of the structural distortions were studied, which can originate also from metalation, protonation or overcrowded peripheral substitution of the free-base porphyrins, as well as from the axial ligation of metalloporphyrins. Our observation may be useful for different spectrophotometric analytical detection and determination methods, e.g. size-selective metal detection using free-base porphyrins (or other ringed chelate ligands), as well as the determination of Lewis bases as potential axial ligands, using metalloporphyrins.

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“…2.624(4) Å . The Ti-OH distance of 1.758(3) Å is short compared with that in [LTi(OH)] (LH 3 = tris(2-hydroxy-3,5-di-tert-butylbenzyl)-amine) (1.810(2) Å ) [13], but is significantly longer than typical terminal Ti@O bonds (e.g., 1.619 Å in oxotitanyl (IV) porphyrin compounds [15]). Thus, 1 is best described as a Ti(IV) hydroxo complex with a hydrogen-bonded triflate rather than an oxo complex hydrogen-bonded with HOTf.…”

Section: X-ray Crystallographymentioning

confidence: 87%

Titanium(IV) terminal hydroxo complexes containing chelating bis(phosphine oxide) ligands

Yi¹,

Williams²,

Leung³

2006

Journal of Organometallic Chemistry

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Molecular stereochemistry of (.alpha.,.gamma.-dimethyl-.alpha.,.gamma.-dihydrooctaethylporphinato)oxotitanium(IV)

Cited by 63 publications

References 22 publications

Synthesis, Reactivity and Structural Chemistry of 5,10,15,20-Tetraalkylporphyrins

Synthesis, Reactivity and Structural Chemistry of 5,10,15,20-Tetraalkylporphyrins

Application of the electronic spectra of porphyrins for analytical purposes: The effects of metal ions and structural distortions

Titanium(IV) terminal hydroxo complexes containing chelating bis(phosphine oxide) ligands

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