桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应（英文）

Reaction of Tungsten Carbonyl with Bis(pyrazol-1-yl)methanes Functionalized by Azaaryl Groups

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L1),2-吡啶基双(3,5-二甲基吡唑)甲烷(L2)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L3)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)5(L=L1或L3),LW(CO)4(L=L1,L2或L3)和LW(CO)3(L=L1或L2)。核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式。在LW(CO)5中,当配体为L1时,其倾向于通过咪唑氮与金属配位,而为L3则倾向于利用吡啶氮与金属作用;在LW(CO)4中,配体L1表现为通过咪唑氮和吡唑氮原子配位的[N,N′]双齿配体,而L2和L3表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)3中,L1和L2起着[N,N,N′]三齿螯合配体的作用。

Reaction of W（CO）6 with （N-methylimidazol-2-yl）bis（3,5-dimethylpyrazol-l-yl）methane （L1）, （pyridin-2- yl）bis （3,5-dimethylpyrazol-1-yl）methane （L2） and （pyridin-4-yl）bis （3,5-dimethylpyrazol-1-yl）methane （L3） yielded complexes LW（CO）5 （L=L^1 or L^3）, LW（CO）4 （L=L^1, L^2 or L^3） and LW（CO）3 （L=L^1 or L^2）, respectively. NMR, IR and X-ray structural analyses indicated that these three ligands possessed variable coordination modes in these complexes. L1 and L3 acted as monodentate ligands through the imidazolyl nitrogen or the pyridyl nitrogen in LW （CO）5. A N,N＇-chelating bidentate ligand through the imidazolyl nitrogen and one pyrazolyl nitrogen was observed in LIW（CO）4, while L2 and L3 acted as N,N-chelating bidentate ligands through two pyrazolyl nitrogens in L2W （C0）4 and L3W（CO）4. A tridentate N,N,N＇-chelating ligand through two pyrazolyl nitrogens and the imidazolyl or 2-pyridyl nitrogen was observed in L^1W（CO）3 and L^2W（CO）3. The different donor ability of these imidazolyl, pyridyl and pyrazolyl nitrogens possibly plays important roles for the structural diversity.