Tetrakis(2,6-dimethyl-4-acetoxyphenyl)pyrene H2 containing flexible acetate functionalities at the para positions of sterically-hindered and rigid aryl rings functions as an inclusion host system. Depending on the orientations of the acetate functionalities, a variety of conformers may indeed be expected. A limited number of the crystal structures of the inclusions compounds of H2 reveal that one indeed observes 2 different conformations for the host based on the orientations of the acetate functionalities. The inclusion compound of H2 with benzene guest molecules is particularly appealing in terms of how the latter are held in trough domains of the host by weak C-H…O and C-H…π hydrogen bonds. More experimentation and analyses of crystal structures of such systems is expected to lead to better insights toward realizing multicomponent molecular crystals in a rational manner.
Tetraarylpyrene host TP exhibits remarkable differential binding of guest molecules in the solid state to include aromatic and aliphatic guests in different domains to permit synthesis of ternary co-crystals in a predictable manner.
compounds constitute rather rare examples of supramolecular isomerism. The thermogravimetric analyses of the inclusioncompounds show that the guest in one of the modifications is released in a relatively higher temperature range. The structural diversity exhibited by the host TP with various guest molecules and its ability to exhibit different forms with the same guest has been to attributed its unique
Steric Inhibition of π-Stacking: 1,3,6,8-Tetraarylpyrenes as Efficient Blue Emitters in Organic Light Emitting Diodes (OLEDs)
作者:Jarugu Narasimha Moorthy、Palani Natarajan、Parthasarathy Venkatakrishnan、Duo-Fong Huang、Tahsin J. Chow
DOI:10.1021/ol7023136
日期:2007.12.1
The sterically congested tetraarylpyrenes 1-3, which can be readily accessed by Suzuki coupling, exhibit no-aggregation (pi-stacking) behavior in both solution and solid states. The indisposed tendency of 1-3 toward crystallization and their moderate molecular dimensions permit exploitation as blue light emitting materials in OLEDs with respectable device performances.
Abundant Lattice Inclusion Phenomenon with Sterically Hindered and Inherently Shape-Selective Tetraarylpyrenes
Tetraarylpyrenes H1−H4 that typify molecularsystems with orthogonal planes and lack hydrogen bonding functional groups were designed as new host systems with three distinct domains for guest inclusion. In particular, H2 and H4 hosts are found to include a variety of guest molecules. We have determined 42 crystalstructures overall (i) to establish the importance of skeletal features of the hosts,