85264-37-5Relevant articles and documents
Synthesis and X-ray crystal structure of derivatives from the N,N-bis(1H-pyrazolyl-1-methyl)aniline(dichloro)Zn(II) complex: Substituent effects on the phenyl ring versus the pyrazole ring
Lee, Hyosun,Kim, Eunhee,Woo, Hyun Yul,Kim, Sunghoon,Lee, Hajin,Kim, Dongil
, p. 135 - 141 (2012)
The reaction of anhydrous ZnCl2 with ancillary ligands, including N,N-bis(1H-pyrazolyl-1-methyl)aniline (L1), N,N-bis(1H-pyrazolyl-1-methyl)-p-methoxyaniline (L2), N,N-bis(1H-pyrazolyl-1-methyl)-p-fluoroaniline (L3) and N,N-bis(3,5-dimethyl-1H-pyrazolyl-1-methyl)aniline (L4), in ethanol yields Zn(II) chloride complexes, i.e., L1ZnCl2, L 2ZnCl2, L3ZnCl2 and L 4ZnCl2. X-ray crystallographic analysis revealed that the Zn atoms of all of the synthesized complexes have a distorted tetrahedral geometry involving a nitrogen atom from each of two pyrazole groups and two chloro ligands. However, the nitrogen atom of the aniline group is not coordinated to the Zn center, resulting in the formation of an eight-membered chelate ring. The catalytic activity of the Zn(II) complexes in the polymerization of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO) results in a higher molecular weight and a narrow polydispersity index (PDI) range.
X-ray crystal structures and MMA polymerization of cadmium(II) complexes with bidentate pyrazole ligands: The formation of monomers or dimers as a function of a methyl substituent on the pyrazole and aniline rings
Kim, Dongil,Kim, Sunghoon,Woo, Hyun Yul,Lee, Ha-Jin,Lee, Hyosun
, p. 445 - 453 (2014/06/09)
The reaction of CdBr2·4H2O with ancillary ligands, N,N-bis(1H-pyrazolyl-1-methyl)aniline (L1), N,N-bis(1H-pyrazolyl-1-methyl)-p-methylaniline (L2), N,N-bis(1H-pyrazolyl-1-methyl)-3,5-dimethylaniline (L3), N,N-bis(3,5-dimethyl-1H-pyrazolyl-1-methyl)aniline (L4) and N,N-bis(1H-pyrazolyl-1-methyl)-2,6-dimethylaniline (L5) in ethanol yields novel Cd(II) bromide complexes, [L1CdBr2] 2, [L2CdBr2]2, [L 3CdBr2]2, [L4CdBr2] and [L5CdBr2]. The X-ray crystal structures of [L 1CdBr2]2, [L2CdBr2] 2 and [L3CdBr2]2 reveal a bromo-bridged dimeric species with crystallographic inversion symmetry. Conversely, [L4CdBr2] and [L5CdBr2] exist as monomeric complexes, presumably due to the steric hindrance between the methyl substituents of the two pyrazole groups in the ligand and cadmium centre for [L4CdBr2], and crowding around the cadmium metal by methyl substituents on the aniline residue in the ligand for [L 5CdBr2]. The geometry at each Cd(II) centre for [L 1CdBr2]2, [L2CdBr2] 2 and [L3CdBr2]2 is best described as a distorted trigonal bipyramid. A distorted trigonal bipyramid is achieved in [L4CdBr2] by coordinative interaction of the nitrogen atom of the aniline unit and the cadmium atom with a σ plane of symmetry, based on the bond length of Cd-Naniline (2.759(7) A). [L 5CdBr2] exists with a distorted tetrahedral geometry involving non-coordination of the nitrogen atom of aniline and the Cd centre, resulting in the formation of an eight-membered chelate ring. The catalytic activity of monomeric, five-coordinated [L4CdBr2] in the polymerization of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO) at 60°C resulted in a higher molecular weight and a narrower polydispersity index (PDI) than those obtained with dimeric [L nCdBr2]2 (Ln=L1, L 2, L3) or monomeric tetrahedral [L5CdBr 2]. Copyright
Synthesis of some new pyrazole-containing chelating agents
Driessen, Willem L.
, p. 441 - 443 (2007/10/02)
Procedures are described involving the condensation of 1-(hydroxymethyl)pyrazole (1a) and 1-(hydroxymethyl)-3,5-dimethylpyrazole (1b) with the following amines (product given in parentheses): ethylamine (2a and 2b), aniline (3a and 3b), N,N'-dimethyl-1,2-ethanediamine (4a and 4b), 1,2-ethanediamine (6a and 6b), diethylenetriamine (7a and 7b), triethylenetetramine (8a and 8b) and ammonia (9a and 9b).All amine hydrogens are completely subsituted by pyrazol-1-ylmethyl groups (compounds 2a - 9a) or (3,5-dimethylpyrazol-1-yl)methyl groups (compounds 2b - 9b with yields being better than 90 percent.
