Isolation and authentication of a sodium bispyrazolylaluminate

Substitution effects in N-pyrazole and N-imidazole derivatives along the periodic table

“…In the case of the pyrazoles and imidazoles substituted by alkaline and alkaline-earth elements, two different minima structures have been found, one interacting with the nitrogen atom and the second one above the ring interacting with its p-cloud, in agreement with recent theoretical and experimental reports [25,26]. The first minima is the global minima in the case of the pyrazoles and alkaline-earth derivatives of the imidazoles while in the case of the alkaline derivatives of the imidazoles the global minima is the second one.…”

Cyclooctadiene Rh(I) Bis- and Tris(pyrazolyl)aluminate Complexes and Their Catalytic Activity on the Polymerization of Phenylacetylene

“…A similar situation is observed in the 13 for which typical distances are in the range of 2.569−2.873 Å. 8,18,22 The t Bu analogue of 1 also exhibits a κ 1 ,κ 2 coordination, but it appears as a dimer with Al-Me-Na bridges and a single THF ligand per Na. 18 In 2 (Figure 2), the aluminate binds the sodium ion in a κ 3 -N,N,N fashion that involves κ 1 coordination of the three 4) in 63% and 89% yield, respectively.…”

“…Although the first report on such a ligand system dates to the 1970s, 7 it was not until a few years ago that one of us reported the first authenticated sodium poly(pyrazolyl)aluminate exhibiting Al−CH 3 bonds. 8 A remarkable series of poly-(pyrazolyl)aluminates with Al−H bonds were also reported, 6,9 with the aim of transferring the aluminate to different metal halides. Significantly, the successful transfer of the hydrotris-(pyrazolyl)aluminate [HAl(Ph 2 pz) 3 ] − to a Zn center was accompanied by the undesired hydride transfer from aluminum to zinc giving [{HAl(Ph 2 pz) 3 }ZnH].…”

“…In stark contrast to the ubiquitous poly­(pyrazolyl)­borates, − very few reports of the heavier aluminum analogues are known. , In addition to easy tuning of steric and electronic properties promoted by the rich pyrazole chemistry, the change from boron to aluminum would be highly valuable due to the availability of ligands with wider bites and redox activity. Although the first report on such a ligand system dates to the 1970s, it was not until a few years ago that one of us reported the first authenticated sodium poly­(pyrazolyl)­aluminate exhibiting Al–CH 3 bonds . A remarkable series of poly­(pyrazolyl)­aluminates with Al–H bonds were also reported, , with the aim of transferring the aluminate to different metal halides.…”

Improved Synthesis and Detailed Characterization of a Hybrid Pyrazole‐TACN Dinucleating Ligand

“…In the solid state the pyrazolato unit in NaL displays an unusual μ 2 -η 2 :η 1 bridging mode, leaving one side arm completely uncoordinated. While such coordination is rarely observed with compartmental pyrazole ligands such as HL, [29] sodium cation complexes formed with simple 3,5-di-alkyl-substituted pyrazole units (alkyl = methyl, [53,54] phenyl, [55] or tertbutyl [53,[55][56][57][58] ) show a diverse range of binding motifs. For example, structural determination of the sodium cation complex [55] Indeed, the pyrazole ring has been referred to as the "most flexible ligand group in coordination chemistry" and displays no fewer than 20 different coordination modes.…”