Solid State and Structural Chemistry Unit, Indian Institute of Science^* Solid State and Structural Chemistry Unit Indian Institute of Science India^**
○Deepak Chopra^* Vijay Thiruvenkatam^** Tayur Narasimha Row^**

In-situ cryo-crystallization of low melting halogenated trifluoroacetophenones reveals the features of short halogenhalogen and halogenoxygen contacts acting cooperatively with weak but highly directional C-HO and C-HF contacts. Studies based on Cambridge structural database indicate directional preferences in halogenhalogen and halogen...oxygen short contacts. Intra-molecular C-HF contacts lock the trifluoroacetophenone moiety conformationally to provide the basic building block.