Meili Zhang, Xiaoming Gao, Danjun Wang
2008
Citations
1
Influential Citations
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Citations
Journal
Zeitschrift für Kristallographie - New Crystal Structures
Abstract
C18H20N2O6, hexagonal, P65 (no. 170), a = 10.58(2) Å, c = 26.58(7) Å, V = 2576.7 Å, Z = 6, Rgt(F) = 0.064, wRref(F ) = 0.173, T = 296 K. Source of material The N,N'-bis(4-hydroxy-3-methoxybenzyl)oxalamide was prepared with some modification to the reported method [1]. The 10 % NaOH solution was added to the corresponding vanillyamine hydrochloride water solution to neutralize the hydrochloride and obtain vanillyamine. Then vanillyamine was reacted with diethyl oxalate (3 : 1 molar ratio) in absolute ethanol, under refluxing for 4 hours. The solution was evaporated under reduced pressure in a rotary evaporator, and the residue was treated with hydrochloric acid (1M) to remove unreacted amine. The crude product was purified from 50 % ethanol. Recrystallization from chloroform gave crystals suitable for X-ray structure analysis (m.p. 212.3 212.6 °C). Elemental analysis − found: C, 60.00 %; H, 5.556 %; N, 7.778 %; calculated for C18H20O6N2: C, 60.350 %; H, 5.912 %; N, 7.582 %. IR and H-NMR data are available in the CIF. Discussion The field of molecular-base magnets has show spectacular advance in the last two decades, especially in the metal-complex based magnetic materials. A number of versatile magnets with multi-dimensional network structures, spontaneous magnetization, and photo-switch property have been developed. So the rational synthetic design for single-molecule magnet should be developed and many efforts have devoted for it [2-5]. It is essential that the chosen ligand possesses suitable coordination groups and sites. We designed and synthesized a series of new ligands that possess two benzyls with methyoxyl and hydroxyl units and a oxalamido-bridge. The first compound with N,N'-bis(2-hydroxy3-methoxybenzyl)oxalamide was already reported [1]. The unit cell of the title crystal structure contains two symmetrically independent molecules, which differ in the position of the hydroxy group. The planes of the two phenyl rings are not parallel with the dihedral angle of 27.51°. In the first molecule the O1− C1−N1−O1A−C1A−N1A stoms of oxalamido are in a same plane, and the dihedral angle is 75.4° between this plan and the plane of the phenyl ring. In the second molecule, the O3−C9−N1− O4−C10−N2 atoms of oxalamido are not in same plane, and the dihedral angle between these planes of O1−C1−N1 and C1A− O1A−N1A is 10.32°. In the unit cell, each molecule is involved in two types of hydrogen bonds. One type occurs between the oxalamide oxygen group and the phenol hydroxy group of the next molecule with d(O−H···O) = 2.906 2.910 Å and /O−H···O = 151.82 153.81°. The other type is between the oxalamide nitrogen group to the oxalamide oxygen group of the next molecule with d(N−H···O) = 2.849 Å and /N−H···O = 158.74°. Through those hydrogen bonds the organic molecules are linked into 2D supramolecular network. Z. Kristallogr. NCS 223 (2008) 173-174 / DOI 10.1524/ncrs.2008.0071 173 © by Oldenbourg Wissenschaftsverlag, München