Crystal engineering in the gem-alkynol family: interplay between strong and weak interactions in structures of 2,3,5,6-tetrahalo
Structures of the title compounds are all mediated by strong cooperative arrangements of O-H.O hydrogen bonds, supported by a variety of weaker interactions which affect the type of O-H.O synthon that is formed. The tetrafluoro compound contains hexameric O-H.O synthons in a supramolecular chair conformation, together with C identical withC-H.F interactions. However, the tetrachloro and tetrabromo compounds both form tetrameric O-H.O synthons. This dominant pattern is supported by halogen.halogen interactions having one C-Cl[Br].Cl[Br] angle close to 180 degrees and the other close to 90 degrees, and by C identical withC-H.Cl[Br] interactions.
Madhavi
NN
School of Chemistry, University of Hyderabad, Hyderabad 500 046, India.
Desiraju
GR
Bilton
C
Howard
JA
Allen
FH