Abstract
The mixture of Sm(NO 3 ) 3. · . 6H 2 O( 0.5 mmol, 0.223 g) and Nsulfonyl amino acids (tsglyH, 1mmol, 0.229 g) in 10 mL aqueous solution was stirred for about 10 minutes to give aclear solution at room temperature. Then the pH value of the reaction mixture was adjusted to 6orsobyslow addition of 0.1 MNaOH solution. After 3ho fs tirring at 65 .°C , 5.mL ethanol solution of 2,2'-bipyridine (0.5 mmol, 0.078 g) was added and the solution was stirred and heated for 6hat65 .°C , and then filtered. The colorless crystal was separated from the mother liquor by slow evaporation at room temperature after 27 days.
The hydrogen atoms bond to Nand Owere found from Fourier difference maps and refined freely. The other Hatoms were positioned geometrically and allowed to ride on their parent atoms, with d(C-H) =0.93 -0.97 Å;and U iso (H) =1.2 U eq (C).
Amino acid is an important biological ligand. It may coordinate to the metal ions by the carboxylate or amino groups. Research on the coordination of metal-amino acid complexes has contributed to our understanding of the function of metal ions in organisms, interactions between amino acids and DNA are of great importance in biochemistry [1, 2] . N-sulfonyl amino acids were found to reproduce the coordination behavior of peptides and their selectivity towards metal ions [3] [4] [5] [6] . N-sulfonyl amino acids (tsglyH) form stable complexes with various transition metal ions, but to our best knowledge their lanthanide(III) (Ln) complexes still remain poorly investigated. Ln complexes with amino acids and its related biologically relevant ligands play an important role in a number of fields of application, for example luminescent probes in biology, medicine and in medical diagnosis in reality, relaxation agents in nuclear magnetic resonance imaging, catalysts for the cleavage of DNA and RNA, drugs for anticancer treatments. The asymmetrical unit in the title crystal structure consists of two crystallographically independent Sm(III) ions, two coordinated water molecules, two coordinated bipy ligands, one uncoordinated bipy ligand and six tsgly ligands. Four of the six tsgly ligands function as bidentate ligands, the other two as monodentate ligands. Each Sm(III) ion is coordinated by two Na toms from bipy molecule and five oxygen atoms from five tsgly ligands and remaining oxygen atoms from water molecules. These eight atoms form adistorted square antiprism. The Sm-Obond lengths in the range of 2.361(3) -2.501(4) Å are close to the normal compared with those reported in the literature. Bipy ligands coordinate Sm(III) ions in chelating mode with the angle being 61.77(1)°[N4A−Sm−N5A]. The coordinated modes of the four bridging carboxyl groups are the same, adopting as yn-syn bidentate fashion. Thus the two Sm(III) ions are bridged by four carboxylate group of tsgly ligands to form abinuclear arrangement with the Sm···Sm distance of 4.439.Å.

reproduce the coordination behavior of peptides and their selectivity towards metal ions [3] [4] [5] [6] . N-sulfonyl amino acids (tsglyH) form stable complexes with various transition metal ions, but to our best knowledge their lanthanide(III) (Ln) complexes still remain poorly investigated. Ln complexes with amino acids and its related biologically relevant ligands play an important role in a number of fields of application, for example luminescent probes in biology, medicine and in medical diagnosis in reality, relaxation agents in nuclear magnetic resonance imaging, catalysts for the cleavage of DNA and RNA, drugs for anticancer treatments. The asymmetrical unit in the title crystal structure consists of two crystallographically independent Sm(III) ions, two coordinated water molecules, two coordinated bipy ligands, one uncoordinated bipy ligand and six tsgly ligands. Four of the six tsgly ligands function as bidentate ligands, the other two as monodentate ligands. Each Sm(III) ion is coordinated by two Na toms from bipy molecule and five oxygen atoms from five tsgly ligands and remaining oxygen atoms from water molecules. These eight atoms form adistorted square antiprism. The Sm-Obond lengths in the range of 2.361(3) -2.501(4) Å are close to the normal compared with those reported in the literature. Bipy ligands coordinate Sm(III) ions in chelating mode with the angle being 61.77(1)°[N4A−Sm−N5A]. The coordinated modes of the four bridging carboxyl groups are the same, adopting as yn-syn bidentate fashion. Thus the two Sm(III) ions are bridged by four carboxylate group of tsgly ligands to form abinuclear arrangement with the Sm···Sm distance of 4.439.Å. 

{'paper_id': '201061868', 'title': "Crystal structure of diaqua-bis(2,2'-bipyridine)-hexa(N-tosylglycinato) disamarium(III) —2,2'-bipyridine (1:1), Sm2(H2O)2(C10H8N2)2(C9H10NO4S)6 ·C10H8N2", 's2_url': 'https://api.semanticscholar.org/CorpusID:201061868', 'source': 'S2ORC'}