02001nas a2200193   4500008004100000245021400041210006900255260000800324300001400332490000700346520115000353100002401503700001901527700002901546700002501575700002701600700002401627856015601651       2013                        eng d00aEvaluation of viability of halogen•••O2N interactions: insight form crystal packing in a series of isomeric halo and nitro substituted triaryl compounds with modular positioning of halogen and NO2 groups0 aEvaluation of viability of halogen O2N interactions insight form  cAPR  a5283-53000 v153 a<p>A series of isomeric triaryl compounds with a modular positioning of the halogen and NO2 groups have been synthesized by the azide–alkyne “click reaction” and have been characterized by single crystal X-ray structure analysis. This isomeric series has provided an opportunity for understanding the efficiency of the bifurcated halogen⋯NO2 synthon in the organization of the molecules in the crystalline lattice. The changes in molecular conformation, crystal packing and supramolecular aggregation due to the change in the relative positioning of the complementary groups, halogen atom and the NO2 group on ring A and ring C respectively, have been discussed. All the isomers synthesized are crystalline and establish the triazole as a reliable linker for crystal engineering oriented molecular synthesis. The 2-NO2 derivatives display in general, a helical architecture and 3-NO2 derivatives exhibit a centrosymmetric dimeric assembly via the complementary C–H⋯O interactions leading to either a helical or a 2-dimensional sheet pattern. The molecular organization in 4-NO2 derivatives revealed in general a 2D sheet pattern.</p>1 aRamana, Chepuri, V.1 aGoriya, Yogesh1 aDurugkar, Kulbhushan, A.1 aChatterjee, Soumitra1 aKrishnaswamy, Shobhana1 aGonnade, Rajesh, G.  uhttps://library.ncl.res.in/content/evaluation-viability-halogen%E2%80%A2%E2%80%A2%E2%80%A2o2n-interactions-insight-form-crystal-packing-series-isomeric