fulltext.study @t Gmail

The phosphorescent behaviors of 9-bromo- and 9-iodophenanthrene in crystals modulated by π–π interactions, C–H⋯π hydrogen bond and C–I⋯π halogen bond

Paper ID Volume ID Publish Year Pages File Format Full-Text
26781 43976 2014 10 PDF Available
Title
The phosphorescent behaviors of 9-bromo- and 9-iodophenanthrene in crystals modulated by π–π interactions, C–H⋯π hydrogen bond and C–I⋯π halogen bond
Abstract

•9-Bromo- and 9-iodophenanthrene have remarkable different phosphorescent behaviors in crystals.•9-Bromo- and 9-iodophenanthrene emit monomer phosphorescence in CD and NaDC media.•Different π–π interactions modulate their phosphorescent behaviors in crystals.•The C–I⋯π halogen bond is more competitive to hydrogen bond in 9-IP crystal.•The C–H⋯π hydrogen bond is more competitive to halogen bond in 9-BrP crystal.

XRD reveals the single crystal of 9-bromophenanthrene (9-BrP) with an infinite herringbone chain structure constructed by itself based on C–H⋯π hydrogen bond and additional edge-to-edge type π–π interaction between phenanthrenes. While, 9-iodophenanthrene (9-IP) possesses an infinite zigzag chain assembled via C–I⋯π halogen bond (XB) and its structure is extended to 3D by typical π–π stacking between phenanthrenes. The interaction energies were estimated by theoretical calculation. The phosphorescence maximum emission wavelengths of two single crystal samples have a significant difference between each other with the 640 nm for 9-BrP and 590 nm for 9-IP, respectively. To understand the effect of interactions between 9-halophenanthrenes in crystals on their phosphorescence, two strategies were utilized to keep them monomers, including 9-halophenanthrenes within hydrophobic cavity of cyclodextrin (CD) with space-regulation of cyclohexane, and sandwiching them in NaDC aggregates. The phosphorescence spectra and decay curves from isolated 9-BrP/9-IP monomers were successfully obtained. All results indicate that the C–H⋯π hydrogen bond and C–I⋯π halogen bond should have smaller effect to their luminescent behaviors while different π–π interactions are the main reason to lead to the obvious different phosphorescent properties between 9-BrP and 9-IP crystals and the largely red-shifted emission bands by approximately 100 nm compared with that of isolated monomers in cyclodextrin/NaDC media or dilute solution of 9-BrP/9-IP. The microcrystal particles separated from suspensions of 9-halophenanthrenes have almost consistent phosphorescent properties compared with their single crystals. Powder XRD confirms the homogeneity of the single crystals and microcrystal particles separated from suspensions of 9-halophenanthrenes and their consistency in structures.

Keywords
π–π interaction; Halogen bond; Hydrogen bond; Phosphorescent behavior; Calculation
First Page Preview
The phosphorescent behaviors of 9-bromo- and 9-iodophenanthrene in crystals modulated by π–π interactions, C–H⋯π hydrogen bond and C–I⋯π halogen bond
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 274, 30 January 2014, Pages 98–107
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us