Fluxional rhenium(I) tricarbonyl halide complexes of pyrazolylpyridine ligands. A detailed nuclear magnetic resonance investigation
摘要:
2,6-Bis(pyrazol-1-yl)pyridine (bppy) reacted with pentacarbonylhalogenorhenium(I) complexes under mild conditions to form stable octahedral complexes of type fac-[ReX(CO)3(bppy)] (X = Cl, Br or 1) in which bppy acts as a bidentate chelate ligand. In solution these tricarbonyl complexes are fluxional with bppy oscillating between equivalent bidentate bonding modes by a twist mechanism involving the breaking/making of two Re-N bonds. 2,6-Bis(3,5-dimethylpyrazol-1-yl)pyridine (tmbppy) and 2-(3,5-dimethylpyrazol-1-yl)-6-(pyrazol-1-yl)pyridine (dmbppy) formed analogous fluxional complexes. The 1,4-Re-N metallotropic shifts of [ReX(CO)3(dmbppy)] interconvert chemically distinct complexes with different solution populations. Under more severe reaction conditions the complex cis-[ReBr-(CO)2(tmbppy)] was formed in which the ligand adopts its more usual terdentate behaviour. Rates and activation energies of these 'tick-tock' twist fluxions have been investigated by one- and two-dimensional NMR methods. Activation energies are dependent on the relative donor strengths of the N atoms, with magnitudes of AG(double dagger) (298.15 K) being 55-56 (bppy), almost-equal-to 69 (dmbppy) and 70-77 kJ mol-1 (tmbppy).
Three new dinuclear silver(I) complexes derived from pyrazolyl type ligands
作者:O. Atakol、H. Fuess、R. Kurtaran、A. Akay、C. Arici、Ü. Ergun、K. C. Emregül
DOI:10.1007/s10973-006-7689-9
日期:2007.11
ligands derivedfrom 2,6-dichlorpyroidine, pyrazol and 3,5-dimethylpyrazole and their silvercomplexes were prepared in methanol media. The complex structures were characterized using IR spectroscopy, X-ray diffraction and elemental analysis. X-ray studies showed the complexes to be dimeric in structure. The two nitrogen atoms of the ligand coordinated the first Ag(I) ion whereas the second Ag(I) ion
Six nickel(II) complexes, using azide and thiocyanate ions, have been synthesized from bis-2,6(pyrazol-1-yl)pyridine (pp) and some methyl derivatives, 2-(3,5-dimethyl(pyrazol-1-yl)-6-(pyrazol-1-yl)pyridine (app) and bis-2,6(3,5-dimethyl(pyrazol-1-yl) pyridine (dmpp) in non-aqueous media. The complex structures were analyzed using elemental analysis, IR spectroscopy and thermogravimetry. Appropriate
由双2,6(吡唑-1-基)吡啶(pp)和一些甲基衍生物2-(3,5-二甲基(吡唑-1)合成了六种使用叠氮化物和硫氰酸根离子的镍(II)配合物非水介质中的-yl)-6-(吡唑-1-基)吡啶(app)和双-2,6(3,5-二甲基(吡唑-1-基)吡啶(dmpp)。用元素分析,红外光谱和热重分析法进行了分析,制备了含有叠氮化物[Nipp(N 3)2 ]·MeOH( I )和硫氰酸盐[Nidmpp(SCN)2 ·MeOH]( VI )的合适的配合物晶体,并给出了分子结构使用X射线衍射确定的复杂 我 被看作是双核如文献中所述,空间群P2 1/ n ,单斜, a = 10.503, b = 10.681, c = 13.291Å, β= 106.56°, Z = 2,而复合物 VI 是单核的,空间群P2 1 / n ,单斜, a = 8.646, b = 12.614, c = 20.697Å,β= 97
New Energetic Copper(II) Complexes With Pyrazolyl Type Ligands
and a molecular structure of this complex was obtained with X-ray diffraction method. Complexes were examined by thermogravimetry and differential scanning calorimetry methods. Thermal decomposition was observed in complexes including two azide groups similar to that seen in explosives. In the complexes containing one azide group, formation of the CuI complexes was observed after thermal decomposition