Clathrates of novel ethylenediamine derivatives: thermal, X-ray crystallographic and conformational analysis of inclusion complexes of N, N′-bis(5-phenyl-5-dibenzo[a, d]cycloheptenyl)ethylenediamine and its 10, 11-dihydro analogue. Issue 47 (24th November 2016)

• Record Type: Journal Article
• Authors: Barton, Benita; Betz, Richard; Caira, Mino R.; Hosten, Eric C.; McCleland, Cedric W.; Pohl, Pieter L.; Taljaard, Benjamin
• Is Part Of: Tetrahedron. Volume 72:Issue 47(2016)
• Page Start: 7536
• Page End: 7551
• Publication Date: 2016-11-24
• Subjects: Host–guest Chemistry -- Inclusion -- Dihalomethane -- X-ray crystallography -- Conformational analysis; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2016.10.007
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: Novel compounds N, N ′-bis(5-phenyl-10, 11-dihydro-5-dibenzo[ a, d ]cycloheptenyl)ethylenediamine3a and N, N′ -bis(5-phenyl-5-dibenzo[ a, d ]cycloheptenyl)ethylenediamine3b are efficient hosts, forming clathrates upon recrystallization from a wide variety of organic solvents. The 1:2 and 1:1 complexes of3a and3b, respectively, with dichloromethane, dibromomethane and diiodomethane were subjected to extensive thermal and X-ray crystallographic studies, and it was found that guests of the thermally less stable complexes reside in channels, while these are accommodated in discrete cavities in the more stable complexes. Host3a adopts similar conformations in its complexes with CH2 Cl2 and CH2 Br2, while a different conformer is involved with CH2 I2 . DFT (B3LYP/6-31G*) geometry optimizations revealed that these conformers are respectively, 8.7 and 7.5 kJ mol −1 less stable than the global minimum energy conformer of3a . Host3b adopts similar conformations in its three complexes, which optimize to the global minimum energy conformer. In the thermally more stable complexes, 3a and3b exist as relatively low energy conformers. Graphical abstract: