Paweł Szlachcic

1,3,4-Triphenyl-7-trifluoromethyl-1H-pyrazolo[3,4-b]quinoline at 293 and 100 K.

In the structure of the title compound, C(29)H(18)F(3)N(3), belonging to the space group P6(5) (or P6(1)), three symmetry-independent molecules are arranged in two chains, with two molecules alternating along the 3(2) axes, whereas the remaining molecule forms a chain along [0001] due to the 6(5) screw axis. The conformation of each of the molecules is stabilized by an intramolecular C-H...N hydrogen bond, with C...N distances in the range 2.964 (6)-3.069 (5) A at room temperature (293 K) and 2.943 (4)-3.084 (4) A at low temperature (100 K). One molecule has its -CF(3) group ordered even at 293 K, which can be explained only by considering its involvement in two weak intermolecular C-H...F interactions, with C...F distances in the range 3.084 (6)-3.302 (5) A at 293 K and 3.070 (3)-3.196 (3) A at 100 K, and also a C-F...N interaction, with a C...N distance of 3.823 (5) A at 293 K and 3.722 (4) A at 100 K. The trifluoromethyl groups in the two remaining molecules are disordered at 293 K, whereas at 100 K the continuous (dynamic) positional disorder of one of the -CF(3) groups (of the molecule forming the chain along [0001]) is totally eliminated while the -CF(3) group disorder remains for the third molecule.

1,3-Diphenyl-8-trifluoro-methyl-1H-pyrazolo-[3,4-b]quinoline.

The 1H-pyrazolo[3,4-b]quinoline (PQ) core of the title molecule, C23H14F3N3, is aromatic and essentially planar (r.m.s. deviation = 0.015 Å) and the two phenyl substituents at positions 1 and 3 are twisted relative to this fragment by 29.74 (7) and 25.63 (7)°, respectively. In the crystal, molecules are arranged along the b axis into stacks via π–π interactions, with an interplanar distance of the PQ core of 3.489 (4) Å.

6-Fluoro-1,3,4-triphenyl-1H-pyrazolo[3,4-b]quinoline benzene hemisolvate.

In the title compound, C28H18FN3·0.5C6H6, the 1H-pyrazolo[3,4-b]quinoline core is almost planar (r.m.s = 0.0371 Å, maximum deviation = 0.0571 Å) and aromatic. The solvent benzene molecules are located around inversion centres. In the crystal, molecules related by centres of symmetry form dimers, with distances of 3.932 (3) Å between best planes through the fused core due to π⋯π stacking. The phenyl substituents at positions 1, 3 and 4, are twisted away from the core, making dihedral angles of 29.66 (7), 44.59 (7) and 67.94 (6)°, respectively.

3-Methyl-1,4-diphenyl-1H-pyrazolo­[3,4-b]quinoline

In the title molecule, C23H17N3, the phenyl substituents at positions 1 and 4 are twisted relative to the central core by 27.09 (5) and 66.62 (4)°, respectively. In the crystal, molecules are assembled into centrosymmetric dimers via π–π stacking interactions between the 1H-pyrazolo[3,4-b]quinoline units, with an interplanar distance of 3.601 (2) Å and by weak intermolecular C—H⋯N interactions.