New didentate bispyrazole ligands forming uncommon eight-ring chelates with divalent copper, zinc and cobalt

The Chelating Ligand 1,3‐Bis(pyrazol‐1′‐yl)propane (Bpp) Enforces a Tetrahedral Geometry in Both CuII and CuI Species

“…In these complexes, the bpp ligands act as didentate chelating ligands to form uncommon eight-atom chelate rings. In earlier work [7] metal complexes with the general formula [M(bpp)X 2 ] (M ϭ Cu 2ϩ , Zn 2ϩ or Co 2ϩ and X ϭ Cl Ϫ or NO 3 Ϫ ) have been reported.…”

“…[1] Chelate rings of different sizes have been the subject of intensive research in the past. For instance, five-to thirteen-membered rings are formed with 2,2Ј-bipyridine, [2] bis(2-benzimidazolyl)ethanes, [3,4] bis(2-benzimidazolyl)propanes [3,5,6] 1,3-bis(pyrazol-1Ј-yl)propane and derivatives [7] and 1,8-bis(3,5-dimethyl-1-pyrazolyl)-3,6-dithiaoctane. [8] Five-membered chelate rings are generally the most stable.…”

“…The X-band EPR spectra of a polycrystalline powder of α-[Cu(bpp) 2 ](BF 4 ) 2 (1) were recorded at room temperature and 77 K. The resolution did not improve upon cooling to 77 K. The spectra show an axial S ϭ 1/2 signal with g values that are normal for Cu II in a slightly distorted tetrahedral environment: g Ќ ϭ 2.11, g // ϭ 2.32 and A // ϭ 13.0 mT. [7] The spectrum of α-[Cu(bpp) 2 ](BF 4 ) 2 in a frozen solution of ethanol was also recorded. This spectrum shows g values that are similar to the g values of the powder spectra, which indicates that the complex is stable in solution.…”

Crystal structure of dichloro[1,3-bis(5-methyl-3-phenylpyrazol-1-yl)propan-2-ol]palladium(II),Pd[(C10H9N2)2C3H5OH]Cl2

“…Broker SMART CCD, φ/ω 58.42° 17640,6223 /obs > 2 a(Iobs), 4764 280 SHELXS-97 [11], SHELXL-97 [12] Source of material A solution of 0.1 g (0.268 mmol) of the newly synthesized ligand 1,3-bis(5-methyl-3-phenylpyrazol-1 -yl)propan-2-ol (Hmppzhp) [6][7][8][9] in 10 ml of methanol was treated with 6.4 mg (0.268 mmol) of LiOH and stirred for 30 min, followed by addition of a solution of 95 mg (0.536 mmol) of PdCh in 10 ml of methanol and stirred further for 3 h at 50 °C. After removal of the insoluble impurities the light yellow solution was evaporated to dryness.…”

Crystal structure of dichloro[1,3-bis(5-methyl-3-phenylpyrazol- 1-yl)propan-2-ol]palladium(II), Pd[(C10H9N2)2C3H5OH]Cl2

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Source of materialA solution of 0.1 g (0.268 mmol) of the newly synthesized ligand 1,3-bis(5-methyl-3-phenylpyrazol-1-yl)propan-2-ol (Hmppzhp) [6][7][8][9] in 10 ml of methanol was treated with 6.4 mg (0.268 mmol) of LiOH and stirred for 30 min, followed by addition of a solution of 95 mg (0.536 mmol) of PdCl2 in 10 ml of methanol and stirred further for 3 h at 50°C. After removal of the insoluble impurities the light yellow solution was evaporated to dryness.

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