Structure of 1,1'-di(4-pyridyl)-2,2',6,6'-bi(4-piperidone) dihydrochloride dihydrate, C20H22N4O22+.2Cl−.2H2O

Abstract

Mr= 457.35, monoclinic, P2Jc, a = 10.3282(19), b= 12.1735(19), c=8.2311 (13)A, fl=92.456(14) ° , V=1033.9 (3) A 3, Z=2, O,,= 1.437, D x= 1.469gcm -3, MoKct, 2=0.71069/k, # = 3.473 cm -1, F(000) = 480, T= 295 (2) K, R(R w) =0.0434 (0.0408) for 1513 observed independent reflections (I > 2.5tr(/)). The dimer lies on a center of symmetry and contains a molecule of water hydrogen- bonded to both the carbonyl oxygen and the chloride ion. The piperidone rings have a distorted chair conformation, flattened at the carbonyl group. The pyridine rings are planar with the nitrogens of the piperidone groups out of this plane. Introduction. As part of a study of the photoelectron- abstraction reactions of six-membered heteroaromatic nitrogen compounds with alcohols (Vittimberga & Morrocchi, 1981), we recently examined the photo- reduction of N-(4-pyridyl)-4-pyridone hydrochloride (1). Irradiation of an aqueous 2-propanol solution of (1) results in the formation of a number of different compounds, among which was the highly crystalline dimer (2), the crystal structure of which is the subject of this communication.