Crystal and molecular structures of the 4-(1H)-pyridone (=L) lanthanide complexes {[GdL(NO3)3(H2O)]�CH3OH}2 and [DyL4(NO3)2](NO3) and of L2HNO3

Abstract

The crystal structures of the title compounds have been determined by single crystal diffraction methods. Crystals of the dysprosium compound are monoclinic, space groupP21/c witha=14.133(4),b=13.438(5),c=14.401 (4)A,β=103.98(2)°,V=2654(1)A3,Z=4,D c =1.82 g cm−3, finalR=0.035. The Dy atom is eight-coordinate with a distorted dodecahedral coordination geometry involving two bidentate nitrate groups and four pyridone oxygen atoms. An erbium complex with analogous stoichiometry was also prepared but not structurally characterized. Crystals of the Gd compound are monoclinic, space groupP21/n, witha=11.226(2),b=9.075(2),c=16.737(3)A,β=93.88(3)°,V=1701(1)A3,Z=2,D c =1.91 g cm−3, finalR=0.042. Each Gd atom is bonded to one pyridone oxygen atom, a water molecule and three bidentate nitrate groups. An oxygen atom of one of the bidentate nitrates additionally serves to bridge pairs of Gd atoms so as to form a dinuclear complex in which each Gd atom is nine-coordinate with a tricapped trigonal prismatic geometry. Crystals of L2HNO3 are monoclinic, space groupI2/a witha=12.479(4),b=6.535(2),c=14.297(6)A,β=96.07(3)°,V=1159(1)A3,Z=4,D c =1.45 g cm−3, finalR=0.057. The pyridones are linked in pairs by very short (2.44 A) symmetrical O⋯H⋯O hydrogen bonds. Each pair is further linked via a nitrate ion by means of N-H⋯O(nitrate)⋯H-N hydrogen bonds, so as to form an extended chevron-like pyridone-pyridone-nitrate-pyridone-pyridone array. Adjacent chains are linked via weak C-H⋯O(NO3) interactions.