Title of article :
Crystal structure of 2,3-dimethoxy-meso-tetrakis(pentafluorophenyl)morpholinochlorin methylene chloride 0.44-solvate
Author/Authors :
Churchill, Serena B. S. Department of Chemistry - University of Connecticut, USA , Sharma, Meenakshi Department of Chemistry - University of Connecticut, USA , Brückner, Christian Department of Chemistry - University of Connecticut, USA , Zeller, Matthias Department of Chemistry - Purdue University, USA
Abstract :
The title morpholinochlorin, C46H16F20N4O3, was crystallized from hexane/methylene chloride as its 0.44 methylene chloride solvate, C46H16F20N4O3·0.44CH2Cl2. The morpholinochlorin was synthesized by stepwise oxygen insertion into a porphyrin using a `breaking and mending strategy': NaIO4-induced diol cleavage of the corresponding 2,3-dihydroxychlorin with in situ methanol-induced, acid-catalyzed intramolecular ring closure of the intermediate secochlorins bisaldehyde. Formally, one of the pyrrolic building blocks was thus replaced by a 2,3-dimethoxymorpholine moiety. Like other morpholinochlorins, the macrocycle of the title compound adopts a ruffled conformation, and the modulation of the porphyrinic π-system chromophore induces a red-shift of its optical spectrum compared to its corresponding chlorin analog. Packing in the crystal is governed by interactions involving the fluorine atoms of the pentafluorophenyl substituents, dominated by C—H⋯F interactions, and augmented by short fluorine⋯fluorine contacts, C—F⋯π interactions, and one severely slipped π-stacking interaction between two pentafluorophenyl rings. The solvate methylene chloride molecule is disordered over two independent positions around an inversion center with occupancies of two × 0.241 (5) and two × 0.199 (4), for a total site occupancy of 88%.
Keywords :
porphyrinoids , pyrrole-modified porphyrins , morpholinochlorins , crystal structure
Journal title :
Acta Crystallographica Section E: Crystallographic Communications