Chi-Phi Wu

A convenient, one-pot azulene synthesis from cyclohepta[b]furan-2-ones and vinyl ether and its analogues. II: Acetals as reagent

Title synthesis by the reaction of cyclohepta[b]-furan-2-ones with acetals of several aldehydes and ketones on heating at 160-190 o C in neat or aprotic solvent

Synthesis and structural characterization of two chain complexes of Mn(II) containing 2-aminopyridinium

Abstract The 2-aminopyridine ligand has been exploited in preparation of divalent metal complexes of the formulae [H(2-ampy)][MnCl3(H2O)] 1 and [H(2-ampy)]2[Mn2Cl6(2-ampy)2] 2, where 2-ampy is 2-aminopyridine. Their crystal structures have been determined by X-ray crystallography. Both complexes self-assemble through similar hydrogen bonding motifs which involve three N–H⋯Cl interactions between the 2-aminopyridinium cation and the chloride atoms. Each repeating unit of complexes 1 and 2, [MnCl3(H2O)]− and [Mn2Cl6(2-ampy)]2−, respectively, is doubly edge-sharing to form one-dimensional chains which are cross-linked by hydrogen bonding to the [H(2-ampy)]+ cations. In complex 2, two different 2-aminopyridine molecules were observed. One bridges the Mn atoms directly, while the other, through hydrogen bonding interaction, bridges Mn atoms via the chloride atoms. The structural role of the 2-aminopyridinium cation on the aggregation of the metal ions is discussed.

Synthesis and structural characterization of face-sharing bioctahedral complexes containing poly(pyrazolyl)borate ligands: [HB(Me2Pz)3BH][X3Mo(μ-X)2(μ-H)MoTp*] (X=Cl or Br; Tp*=HB(Me2Pz)3; Pz=pyrazolyl)

Abstract From a solution prepared by reaction of Mo2(O2CCH3)4 with KTp* (Tp*=hydridotris(3,5-dimethylpyrazolyl)borate, HB(Me2Pz)3), in glyme at room temperature, followed by addition of (CH3)3SiCl and (CH3)3SiBr to the red solution in refluxing THF, brown [HB(Me2Pz)3BH][Cl3Mo(μ-Cl)2(μ-H)MoTp*] (1), and [HB(Me2Pz)3BH][Br3Mo(μ-Br)2(μ-H)MoTp*] (2), respectively, can be prepared. A pink product [HB(Me2Pz)3BH][MoBr4(Me2PzH)2] (3), was also obtained during the preparation of 2. Their structures have been determined by X-ray crystallography. The anions of complexes 1 and 2 consist of two octahedra sharing a common triangular face, so that the Mo atoms are bridged by one H and two halogen atoms. The unsymmetrical metal centers are also chelated by tridentate Tp* ligands and coordinated by three halogen atoms. In contrast to the symmetrical [Mo2X8H]3− (X=Cl, Br or I) ions whose MoMo distances are hardly affected by the change in the size of the bridging halide atom, the variation of the MoMo distance from 1 to 2 is approximately 0.040 A. The formation of the cation [HB(Me2Pz)3BH]+ and the anion [MoBr4(Me2PzH)2]− shows the ready BN bond cleavage of the Tp* ligand.

Bridging bonding mode in a metal-pteridine complex. Synthesis and structural characterization of Pt2Cl4(Hmp)2 (Hmp=4-hydroxy-2-mercaptopteridine)

Abstract Reaction of PtCl2 with Hmp (Hmp=4-hydroxy-2-mercaptopteridine) afforded the unique platinum–pteridine complex Pt2Cl4(Hmp)2, in which the Hmp ligand bridges the metal centers through the pyrazine ring nitrogen atom and the sulfur atom in a neutral form. This bonding mode is in marked contrast to the usual O4,N5-chelation mode of the pteridine units found in all the other reported complexes.

Bis(4,4′-methyl­enedicyclo­hexyl­aminium) μ-benzene-1,4-dicarboxyl­ato-bis­[tri­chlorido­zinc(II)] tetra­hydrate

The title compound, (C13H28N2)2[Zn2(C8H4O4)Cl6]·4H2O, was prepared by the reaction of ZnCl2·6H2O, benzene-1,4-dicarboxylic acid and 4,4′-diaminodicyclohexylmethane in methanol. The [Zn2Cl6(C8H4O4)]4− anions lie on centres of inversion and comprise two ZnCl3 groups bridged by benzene-1,4-dicarboxylate. In addition to N—H⋯Cl and N—H⋯O hydrogen bonds between the cations and anions, solvent water molecules form O—H⋯O and O—H⋯Cl hydrogen bonds to give a three-dimensional network.

CCDC 887649: Experimental Crystal Structure Determination

Related Article: Badugu Devendar, Chi-Phi Wu, Chi-Yuan Chen, Hung-Chang Chen, Chung-Hao Chang, Chien-Kuo Ku, Cheng-Yin Tsai, Chieh-Yuan Ku|2013|Tetrahedron|69|4953|doi:10.1016/j.tet.2013.04.034

N,N-Bis(6-methyl-2-pyrid-yl)formamidine.

In the crystal structure of the title molecule, C13H14N4, the two pyridyl rings are not coplanar but twisted about the C—N bond with an interplanar angle of 71.1 (1)°. In the crystal, the molecules form dimers, situated on crystallographic centres of inversion, which are connected via a pair of N—H⋯N hydrogen bonds. C—H⋯π-electron ring interactions are also present in the crystal structure. The title molecule adopts an s–cis–anti–s–cis conformation in the solid state.