Syntheses and Crystal Structures of Copper(II) Bis (pyrazolyl)acetic Acid Complexes

摘要: The reaction of bis(pyrazol-1-yl)acetic acid (L) with copper(II) bromide provides two new complexes: [Cu(L-H)Br(µ-Br)]2 (1) and [Cu(L)2]⋅4H2O (2). Complex 1 is prepared by the stoichiometric L-H in tetrahydrofuran. Dissolution methanol causes its conversion into bis-ligated complex (2), a highly hygroscopic material. 2 can also be synthesized directly CuBr2 methanol. dimeric, interlinked bridging ligands, possesses terminal ligands on each copper atom. pyrazolyl coordinate nitrogen atoms to complete coordination sphere copper, resulting distorted geometry that lies between trigonal bipyramidal or square pyramidal wide bond angles trans-oriented ligands. assumes pseudo-trigonal prismatic deprotonated carboxylic interacts weakly copper. Reaction (L-H) these compounds represent first, well-defined, independent supported base bis(pyrazolyl)acetic ligand.