Wei-Zheng Shen

The synthesis and crystal structure of [M{H2B(tz*)2}2(H2O)] (M=Cu, Zn and tz*=3,5-dimethyl-1,2,4-triazole)

Abstract New ligand [KH2B(tz*)2] (tz*=3,5-dimethyl-1,2,4-triazolyl) has been synthesized and the reactions of two different metal salts (copper and zinc) with the new ligand in agar gave two similar crystalline polymorphic forms: [Cu{H2B(tz*)2}2(H2O)] (1) and [Zn{H2B(tz*)2}2(H2O)] (2). A single crystal X-ray study revealed that the compound 1 was the monoclinic system with space group C2/c and a=8.462(3) A, b=14.039(6) A, c=19.991(8) A, β=94.622(7)°, Z=4, R1=0.0451, wR2=0.1110. And the compound 2 was the monoclinic system with space group C2/c and a=8.4214(4) A, b=13.8765(7) A, c=20.2969(6) A, β=95.615(2)°, Z=4, R1=0.0667, wR2=0.1375. The metal(II) ion in the complex is five-coordinated with four nitrogen atoms which come from triazolyl and one oxygen atom which come from water molecular. In both compounds, the hydrogen atoms of water molecule are connected by hydrogen bonding with N atoms of two adjacent complex molecules to form 2-D planes. The spectroscopic results are consistent with the crystallographic study.

The first example of half-sandwich cobalt(III) complex with hydrotris(pyrazolyl)borate ligand

Abstract This paper presents the synthesis, crystal structure and spectroscopic properties of a novel half-sandwich mononuclear cobalt(III) complex with hydrotris(3,5-dimethylpyrazolyl)borate ligand and thiocyanate [Tp*Co(Hpz*)(NCS)2]·H2O·CH3OH (Tp*: hydrotris(3,5-dimethyl- pyrazolyl)borate, Hpz*: 3,5-dimethylpyrazole). The structure was determined by X-ray diffraction. The complex crystallizes in the monoclinic system, space group Cc, a=18.591(6) A, b=10.536(3) A, c=17.568(5) A, β=11.284(5)°, Z=4, R1=0.0501, wR2=0.1179. The cobalt(III) ion in the complex is six-coordinated with nitrogen atoms, three from Tp*, two from pyrazole and two from two thiocyanates, to form octahedral environment. The hydrogen atoms of O(2) of water molecule are connected by hydrogen bonds with S atoms of two adjacent complex molecules to form 1-D chains. The hydrogen atom of N(8) of complex molecule is connected by hydrogen bond with methanol. The spectroscopic results are consistent with the crystallographic study.

Synthesis and crystal structures of [Cu{HC(pz)3}(SCN)2] and [Cu(tacn)(SCN)2] (HC(pz)3: Tris(pyrazolyl)methane; tacn: 1,4,7-triazacyclononane)

Two novel copper complexes with formulae [Cu{HC(pz)3}(SCN)2] 1 and [Cu(tacn)(SCN)2] 2 have been obtained by the reaction of HC(pz)3 and tacn with a copper salt and thiocyanate. The complex 1 crystallises in the orthorhombic space group Aba2, with lattice parameters a = 25.7715(7) Å, b = 7.5034(3) Å, c = 16.2328(6) Å, Z = 8, R1 = 0.0613, wR2 = 0.1353. The complex 2 crystallises in the orthorhombic space group P2(1)2(1)2(1), with lattice parameters a = 8.640(4) Å, b = 10.890(5) Å, c = 13.833(6) Å, Z = 4, R1 = 0.0343, wR2 = 0.0679. Both complexes are isostructural mononuclear compounds. The central copper ions of 1 and 2 are coordinated by three nitrogen atoms of the ligands and two nitrogen atoms of the two thiocyanate ions. Depending on the ligands, the two complexes forms different weak bonds resulting in different crystal packing.

CCDC 196152: Experimental Crystal Structure Determination

Related Article: Wei-Zheng Shen, Long Yi, Peng Cheng, Shi-Ping Yan, Dai-Zheng Liao, Zong-Hui Jiang|2004|Inorg.Chem.Commun.|7|819|doi:10.1016/j.inoche.2004.04.008