159152-17-7Relevant articles and documents
Bridged bis-BODIPYs: Their synthesis, structures and properties
Kesavan, Praseetha E.,Das, Sudipta,Lone, Mohsin Y.,Jha, Prakash C.,Mori, Shigeki,Gupta, Iti
, p. 17209 - 17221 (2015)
A series of bis-BODIPYs 1-6 bridged via thiophene, furan, N-alkylcarbazole, triphenyl-amine, para- and meta-phenylene groups have been synthesized and characterized by various spectroscopic techniques. The change in the spectroscopic properties of bis-BODIPYs upon varying the size of spacers was studied. X-ray crystal structures of three bis-BODIPYs containing triphenylamine, para- and meta-phenylene bridges were solved. Intermolecular C(H)...π and π...π stacking interactions were observed in solid state structures of three bis-BODIPYs. The dihedral angles between the spacer unit and two boron-dipyrrin units were lower in all three compounds as compared to their corresponding monomers. This suggests increased interactions between the two boron-dipyrrin units in molecules which are in turn reflected in the anodic shifts in their reduction potentials. DFT studies indicated effective electronic interactions between spacers and two boron dipyrrin units in all the bis-BODIPYs. The calculated HOMO-LUMO gap was found to be lower for bis-BODIPY having bulky carbazole spacers and higher for bis-BODIPY having smaller furan spacers. Changing the spacer size clearly affected the spectroscopic properties of the bis-BODIPYs and red shifted absorption and emission maxima were observed for bis-BODIPYs with furan and thiophene spacers as compared to bis-BODIPYs with phenylene or bulky aromatic spacers.
One-flask synthesis of meso-substituted dipyrromethanes and their application of the synthesis of trans-substituted porphyrin building blocks
Lee,Lindsey
, p. 11427 - 11440 (2007/10/02)
The reaction at room temperature of an aldehyde with excess pyrrole in the absence of solvent affords the meso-substituted dipyrromethane. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. The dipyrromethane is purified by crystallization or by flash chromatography on silica with eluants containing 1% triethylamine. The reaction is compatible with aliphatic or aromatic aldehydes, including 2,6-disubstituted benzaldehydes. Nine dipyrromethanes have been prepared in this manner in yields of 47-86%, indicating the broad scope of the reaction. The dipyrromethanes are stable in the purified form in the absence of light and air. Similar reaction with terephthalaldehyde and pyrrole affords the corresponding bis-dipyrromethane. The reaction of a meso-substituted dipyrromethane with an aldehyde under the conditions of the two-step one-flask porphyrin synthesis affords a direct route to trans-substituted meso-porphyrins. Acidolysis of the dipyrromethane is negligible under the conditions of the porphyrin-forming reaction. Four porphyrins bearing peripheral functional groups and facially-encumbering groups have been prepared which serve as key building blocks in the synthesis of linear porphyrin arrays.
