C-H-CENTER-DOT-CENTER-DOT-CENTER-DOT-O HYDROGEN-BOND PATTERNS IN CRYSTALLINE NITRO-COMPOUNDS - STUDIES IN SOLID-STATE MOLECULAR RECOGNITION

Several C-H...O hydrogen bond patterns (I-V) have been studied in the crystal structures of organic nitro compounds. It is shown that NO2 and NMe(2) groups have complementary functionalities in C-H...O mediated molecular recognition in the solid state (pattern I). The role of cooperativity in stabilising these weakly hydrogen bonded networks has been studied computationally by examining aggregates of the prototype molecule N,N-dimethylnitroamine. Other geometrically characteristic C-H...O patterns (II-V) are found commonly in these crystal structures especially among nitroalkenes and nitroaromatics and such patterns are expected to be of utility in supramolecular assembly.