Ya-Min Li

Two binuclear tetracarboxylate-bridged complexes: syntheses, structures, and properties

Cu2(C9N5H9)2(C6H5CO2)4 (1) and Zn2(C9N5H9)2(C10H7CH2CO2)4 (2) have been synthesized by hydrothermal methods with 2,4-diamine-6-phenyl-1,3,5-triazine (phdat) and aromatic carboxylic acid (benzoic acid (ba) or naphthylacetic acid (naa)) as ligands and characterized by single-crystal X-ray diffractions, elemental analyses, infrared spectra, magnetism, fluorescence spectra, and thermogravimetric analyses. In 1 and 2, the two metals are bridged by four carboxylates in paddle-wheel-shaped binuclear [M2(CO2)4] units (M=Cu (1) and Zn (2)) and coordinated by one nitrogen from phdat, forming five-coordinate centers. The temperature-dependent magnetic susceptibility of 1 was obtained from 300 to 2 K, showing an anti-ferromagnetic interaction between Cu(II)s. Compound 2 exhibits solid state fluorescence at 404 nm upon excitation at 304 nm.

Syntheses and structures of three chiral complexes derived from nucleophilic addition of L-proline to di-2-pyridyl ketone

In the presence of nickel acetate, a chiral ligand, (S)-Hdphp ((S)-N-[di(2-pyridyl)-hydroxy-methyl]-proline), was synthesized in situ by nucleophilic addition of L-proline to di-2-pyridyl ketone. Based on this ligand, three chiral mononuclear complexes, {Ni[(S)-dphp](DMF)(H2O)}(ClO4) (1), {Ni[(S)-dphp](H2O)2}(ClO4)(H2O)1.5 (2), and {Ni[(S)-dphp](SCN)(H2O)} (3), have been obtained and characterized by single-crystal X-ray diffraction, elemental analyses, and infrared spectra. By virtue of charge-assisted O–H ··· O hydrogen-bonding interactions, all the complexes possess double chain structures. The double chains were connected into 2-D networks via π ··· π stacking and CH ··· π interactions in 1. For 2, O–H ··· O hydrogen-bonding interactions between free water molecules and other oxygens as well as π ··· π stacking and CH ··· π interactions extend the chains into a 3-D network. Complex 3 exhibits 3-D structure via O–H ··· S interactions.

Syntheses, structures and characterization of the tetranuclear tin(IV) oxysulfide clusters ( n -Bu4N)2[Sn4(μ4-O)S5(edt)2X2] (X=Cl, Br) (edt=1,2-ethanedithiolate)

During attempts to prepare cubane-like clusters from the precursor (Bu4N)2[Sn3S4(edt)3] (edt = 1,2-ethanedithiolate), two new tetranuclear tin(IV) oxysulfide clusters, (Bu4N)2 [Sn4(μ4-O)S5(edt)2Cl2] (1) and (Bu4N)2[Sn4(μ4-O)S5(edt)2Br2] (2) were unexpectedly obtained by reaction of (Bu4N)2[Sn3S4(edt)3] with SnX2 (X = Cl, Br). X-ray crystal structure analyses show that the two compounds possess an isostructural anionic cluster with a highly distorted tetrahedral metal skeleton. The two compounds have been characterized spectroscopically.