کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1327090 977462 2008 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Cobalt(II) complexes with disubstituted 3-aminopyrazole derivative: Mononuclear Co(II) complex with in situ prepared formamidine ligand
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Cobalt(II) complexes with disubstituted 3-aminopyrazole derivative: Mononuclear Co(II) complex with in situ prepared formamidine ligand
چکیده انگلیسی

In the reaction of Co(NO3)2 · 6H2O with 4-acetyl-3-amino-5-methylpyrazole (aamp) two octahedral Co(II) complexes, [Co(aamp)2(H2O)4](NO3)2, 1, and [Co(ampf)(MeOH)2NO3]NO3 (ampf = N,N′-bis(4-acetyl-5-methylpyrazole-3-yl)formamidine), 2, were obtained, depending on the reaction conditions. The presence of water in the reaction system leads to incorporation of water molecules into the crystal lattice and 1 was formed. In an anhydrous environment, due to addition of CH(OEt)3, the fusion of two aamp was induced through their NH2-groups, incorporating the methine group of CH(OEt)3. As a result, complex 2, containing an adenino-mimetic NNO pharmacophore ligand, was obtained. The crystal and molecular structure of both compounds was determined. The coordination of aamp in 1 was achieved through N2 of the pyrazole ring. On the contrary, in 2, an unusual coordination mode of pyrazole is found: one of the pyrazole moieties, due to steric hindrance, coordinates through the oxygen atom of the acetyl group instead of N2. The complexes were characterized by elemental analysis and electronic spectra. For 2 a comprehensive IR spectral analysis is given. The metal–ligand interactions in 2 are analyzed by quantum chemical computations. The desolvation mechanism of both compounds is discussed in detail.

The novel [Co(ampf)(MeOH)2NO3]NO3 complex with a formamidine-type ligand is obtained by an one-step template synthesis. It is characterized by X-ray diffraction, FT-IR and UV–Vis spectroscopy, elemental and thermal analysis. The quantum chemical computations indicate a comparable involvement of the ligand donor atoms in the total charge transfer.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Organometallic Chemistry - Volume 693, Issue 1, 1 January 2008, Pages 77–86
نویسندگان
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