i-Ling Hu

Ligand isomerism-controlled structural diversity of cadmium(II) perchlorate coordination polymers containing dipyridyladipoamide ligands

The syntheses, structures and ligand conformations of three Cd(II) coordination polymers [Cd(L1)(ClO4)2]∞ [L1 = N,N′-di(2-pyridyl)adipoamide], 1, {[Cd(L2)2(CH3OH)2](ClO4)2·2CH3OH}∞ [L2 = N,N′-di(3-pyridyl)adipoamide], 2 and [Cd(L3)2(ClO4)2(CH3CH2OH)2]∞ [L3 = N,N′-di(4-pyridyl)adipoamide], 3, are reported. Their structures have been characterized by X-ray crystallography. Complex 1 forms 1D zigzag chains, while complex 2 forms 2D pleated sheets which are positioned in an ABAB manner. Complex 3 shows a rare 3D entanglement from parallel polycatenation of 3-fold interpenetrated square layers. While the L1 ligands in 1 adopt AAAtrans conformations and the L2 ligands in 2 adopt GAGtrans conformations, the L3 ligands in 3 adopt AAAtrans and AGAtrans conformations. The structural types of the Cd(II) coordination polymers can be directed by ligand isomerism.

Methyl 4-[(pyrimidin-2-yl)carbamo-yl]benzoate.

Molecules of the title compound, C13H11N3O3, are connected into centrosymmetric dimers via intermolecular N—H⋯N hydrogen bonds, generating an R 2 2(8) motif. The pyrimidine and the phenyl rings are twisted with respect to each other by an interplanar angle of 61.3 (1)°.

N-(6-Methyl-2-pyrid-yl)formamide.

The molecule of the title compound, C7H8N2O, is essentially planar with a maximum deviation of 0.0439 (1) Å from the best plane. In the crystal, N—H⋯O hydrogen bonds between self-complementary amide groups join molecules into centrosymmetric dimers.

Bis[μ-N-(pyridin-2-yl)methane­sulfon­amido-κ2N:N′]silver(I)

In the title compound, [Ag2(C6H7N2O2S)2], the AgI atom is coordinated by two N atoms from two N-(pyridin-2-yl)methanesulfonamidate anions in a slightly bent linear geometry [N—Ag—N = 166.03 (7)°]. The AgI atoms are bridged by the N-(pyridin-2-yl)methanesulfonamidate anions, forming a centrosymmetric dinuclear molecule, in which the Ag⋯Ag distance is 2.7072 (4) Å.

Methyl 4-[N-(5-bromo­pyrimidin-2-yl)carbamo­yl]benzoate

In the title compound, C13H10BrN3O3, the pyrimidine and benzene rings are twisted with an interplanar angle of 58.4 (1)°. The secondary amide group adopts a cis conformation with an H—N—C—O torsion angle of 14.8 (1)°. In the crystal, molecules are connected into inversion dimers via pairs of N—H⋯N hydrogen bonds, generating an R 2 2(8) motif. The dimers are further connected through a C—Br⋯O interaction [3.136 (1) Å and 169.31 (1)°] into a chain along [110]. Weak C—H⋯N hydrogen bonds between the methyl benzoate groups and pyrimidine rings are also observed in the crystal structure.

6,6′-Dimethyl-2,2′-[oxalylbis(aza­nedi­yl)]dipyridinium dichloride acetonitrile solvate

In the crystal structure of the title compound, C14H16N4O2 2+·2Cl−·CH3CN, weak intermolecular N—H⋯Cl hydrogen bonds are found between the H atoms bound to the pyridine and amine N atoms and the chloride anions. The asymmetric unit consits of one half cationic molecule which is located on a centre of inversion, one chloride anion in a general position and one half acetonitrile molecule which is located on a twofold axis. Because of symmetry, the C—H hydrogens of the acetonitrile solvent molecule are disordered over two orientations.