Source of materialThe mixture of Co(OAc) 4. · . H 2 O( 124 mg, 0.5 mmol) and (3-carboxyphenyl)sulfonyl]glycine (132 mg, 0.5 mmol) was stirred into 15 mL aqueous solution, which was refluxed about 1h.Then the pH was adjusted to 6orsowith 1Msolution of NaOH. The reaction mixture was heated on awater bath for 12 hat60°C, and then filtered. The red crystals were separated from the mother liquor by slow evaporation at room temperature after 1week.
Experimental detailsAll hydrogen atoms were first found in the difference electron density maps, and then placed in the calculated positions. In order to obtain reasonable bond length and U eq ,the hydrogen atom attached to N1 were found from difference Fourier maps and refined freely. The remaining Hatoms were refined by riding model with Ueq(H) =1.2 U eq (C).
DiscussionInorganic-organic hybrids have developed into an important class in the family of porous materials. This is due to their interesting magnetic or optical properties, their potential application in the fields of gas and liquid separation and storage, their catalysis, as well as their drug delivery [1][2][3][4][5][6][7]. Although many efforts have been devoted to the preparation of specific frameworks including one-, two-and three-dimensional structures, the preparation of the MOFs under rational control is still of great challenge. Amino acid is the fundamental structure unit of biomacromolecules, such as protein and enzyme, and it is also the important biomicromolecular ligand inside the life body. In recent years, the investigation of mixed-ligand complexes of transitional metal ions with N-protected amino acids has attracted considerable interest. The asymmetric unit of the title crystal structure consists of two 4,4-bipyridine molecules, one (3-carboxyphenyl)sulfonyl]-glycinate anion, three coordinating water molecules and one free water molecule. The coordinating (3-carboxyphenyl)sulfonyl]-glycinate anion acts as amono-dentate ligand. The Co ion is sixcoordinated (CoN 2 O 4 ), and the coordination polyhedron can be described as an distorted octahedron. The equatorial plane is formed by O1, O7, O8 and O9 from one (3-carboxyphenyl)-sulfonyl]glycine anion and three water molecules. The Co-O bond lengths are in the range of 2.095(2) -2.142(2) Å.The axial position is occupied by two Na toms from two 4,4-bipyridine molecules. The axial distance Co1-N2 and Co1-N4 are 2.230(2) Å and 2.241(2) Å,respectively. The Co-Oand Co-N bond lengths are close to those found in cobalt(II) complexes of N-protected amino acids and bipyridine ligands. Multiple hydrogen bonds are known to cooperatively exert influence on the control of molecular self assembly in chemical and biological systems. Several kinds of hydrogen bonding are observed in the crystal structure: (a) hydrogen bonding between coordinated water oxygen atoms and uncoordinated oxygen atoms of glycine anion motif (O7−H2W···O2 with the bond distance of 2.635(2) Å and bond angle of 172.5°); (b) hydrogen bonding between coordinated water oxygen atoms and uncoordinated...