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In the title compound, C12H10N2O, the dihedral angle between the phenyl and pyridine rings is 64.81 (1)°. Inter­molecular N—H⋯O hydrogen bonds connect the mol­ecules into chains running along the b axis.

We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ~2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO(3) in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

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The title compound, C18H16N2O, crystallizes in the triclinic space group P1, with four independent mol­ecules in the asymmetric unit wherein two mol­ecules have an irregular -ac, -ac, +ap conformation (ap, antiperiplanar; ac, anticlinal), while the other mol­ecules exhibit a different, +ac, +ac, +ap conformation. The planar (r.m.s. deviation = 0.006 Å in each of the four molecules) quinoline ring systems of the four mol­ecules are oriented at dihedral angles of 32.8 (2), 33.4 (2), 31.7 (2) and 32.3 (2)° with respect to the benzene rings. Intra­molecular N—H⋯N inter­actions occur in all four independent mol­ecules. The crystal packing is stabilized by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds, and are further consolidated by C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.728 (3), 3.722 (3), 3.758 (3) and 3.705 (3) Å].