Stability of nonplanar N-methylporphyrins and their zinc complexes

Use ofF-BODIPYs as a Protection Strategy for Dipyrrins: Optimization of BF2Removal

“…Compound 20 was prepared previously from the dipyrrin·HBr salt using GP1 and repurified using column chromatography on silica, eluting with 5–10% ethyl acetate in hexanes. Mp 118–122 °C; 1 H NMR (CDCl 3 , 500 MHz) δ 6.99 (s, 1H), 6.00 (s, 1H), 2.51 (s, 6H), 2.39 (q, 2H, J = 7.7 Hz), 2.23 (s, 3H), 2.17 (s, 3H), 1.07 (t, 3H, J = 7.7 Hz); 13 C NMR (CDCl 3 , 125 MHz) δ 156.7, 155.4, 140.0, 137.7, 133.3, 133.0, 132.6, 119.4, 118.4, 17.5, 14.7, 14.6, 12.8, 11.3, 9.5; 11 B { 1 H} NMR (CDCl 3 , 160 MHz) δ 0.81 (t, J = 32.7 Hz); LRMS-ESI ( m / z ): 299.1 [M + Na] + ; HRMS-ESI ( m / z ): [M + Na] + calcd for C 15 H 19 N 2 BF 2 Na 299.1502; found, 299.1502; ε 519 nm = 95 000.…”

Advances in the Chemistry of Dipyrrins and Their Complexes

“…Data pertaining to the solvation properties, light absorption spectra, and thermal decomposition values of some dipyrrin hydrobromide salts, bis(dipyrrin) hydrobromide salts, and dipyrrinato metal complexes were reported recently. 3,4,[47][48][49][50] In a study of the antioxidant properties of two bis(dipyrrin)s and several other oligopyrrolic compounds it was shown that the 1,1′-linked bis(dipyrrin), which mimics the linkage of natural linear tetrapyrrolic compounds, exhibited effective antioxidant activity while the unnatural 2,2′-bis(dipyrrin) did not. 51 Free-base dipyrrins are regarded as relatively strong bases.…”

“…194,196 Diversification of the methods for calix- [4]phyrin(1.1.1.1) synthesis have allowed for placement of two substituents at each of the sp 3 -hybridized meso-like centers, making the molecules more resistant to oxidation and rearrangement. Most synthetic pathways to transporphodimethenes produce products in which the two sp 3 hybridized meso-like centers bear the same substituents. These methods include the following: (1) photoreduction of porphyrins (Figure 42), 189 (2) reductive meso-alkylation of porphyrins (Figure 43), 197 (3) oxidation of calix [4]pyrroles (Figure 44), 192 (4) dealkylation of calix [4]pyrroles (Figure 45), 198 and ( 5) acid-catalyzed condensation of pyrrolic compounds with carbonyl-containing molecules, followed by oxidation as appropriate.…”

“…203 In this example structural data of the solid-state material showed that the usual preference of calix [4]phyrin(1.1.1.1)s for the syn-axial configuration was not followed; however, 1 H NMR spectra of the two isomers in solution show significant motion in the structure. 203 Most of the methods for synthesizing calix [4]phyrin-(1.1.1.1) derivatives provide products in which the two sp 3 hybridized meso-like centers bear the same substituents. Asymmetrically substituted trans-porphodimethenes are most efficiently synthesized by MacDonald-type condensations of dipyrromethenes, thus providing modular control over the substitution patterns of the products.…”

Stability of Magnesium(II) Azaporphyrins and Porphyrazines

“…Мы полагаем, что регистрируемые изменения не связаны с процессами деструкции азапорфиринового макроцикла, а обус-ловлены либо удалением молекул растворителя, либо [34] наличие объемных заместителей уменьшает жесткость молекулы и дестабилизирует молекулу к термической деструкции. Наиболее стабильным комплексом оказался MgAAAA, по-видимому, вследствие наличия атомов фтора, увеличивающих устойчивость к термическому разложению соединения.…”