Effect of methylation on the coordination of copper by small azacryptands; the role of geometrically constrained hydrogen bonding in stabilizing terminally coordinated oxygen species.
Treatment of N-methyl substituted aminocryptand hosts with copper(II) generates monocopper(II) cryptates where copper(II) coordinates an oxygen-centered species, formally H3O+, which is also strongly hydrogen bonded to three aminocryptand N-methyl atoms via bonds which may best be viewed as NH(delta+)...O(delta-) in consequence of charge transfer. The strength of this hydrogen bonding precludes successful competition of another copper ion for the second coordination site thus suppressing formation of any Cu-Cu bonded average-valent system.
Farrell
David
D
Dept. of Chemistry, Queens University, Belfast BT9 5AG, UK.
Harding
Charles J
CJ
McKee
Vickie
V
Nelson
Jane
J