Two complexes of copper(ii) salts with 5-amino-3-(pyrid-2-yl)-1H-pyrazole, the prototype for a new class of ditopic ligand

Abstract

The title ligand ('L') in crystalline [CuBrL(2)]Br.CH(3)OH and [Cu(OH(2))L(2)]SO(4).H(2)O.CH(3)OH chelates to both the copper(II) cations and the charge-balancing anions.

Iron(ii) complexes of 2,6-di(1H-pyrazol-3-yl)-pyridine derivatives with hydrogen bonding and sterically bulky substituents

“…24,25 Treatment of L 1 with pinacoyl chloride in acetonitrile precipitated the hydrochloride salt of L 2 , which was converted to its free base with aqueous Na 2 CO 3 . 19 Reactions of L 1 with acyl or benzoyl chloride also yielded the corresponding di(methylamido) or di(phenylamido) derivatives, which unfortunately proved too insoluble for use in complexation studies. In our hands the first step in the synthesis of L 3 , a double Claisen condensation reaction, 25 was sluggish and yielded significant amounts of the singly condensed byproduct as well as the expected bis(-diketone) shown in Scheme 2.…”

“…These include additional protic substituents, designed to convert the pyrazolyl N-H functions into   ; 19,20 bulky, hydrophobic tertbutyl substituents, which we have previously found to promote novel metal/pyrazole assembly structures (L 3 , L 4 ); [21][22][23] and, a combination of the two (L 5 ). Ligands L 4 and L 5 are the first examples of 3-bpp derivatives bearing an unsymmetric pattern of pyrazole substituents (Scheme 1, R ≠ R').…”

Pyrazole‐Based Ligands for the [Copper–TEMPO]‐Mediated Oxidation of Benzyl Alcohol to Benzaldehyde and Structures of the Cu Coordination Compounds

“…[37] The Cu-N and Cu-Br bond lengths are comparable to those of related Cu II N 4 Br chromophores. [39,40] The lattice contains one water molecule and one acetonitrile of solvation as well as a bromide anion. The non-coordinating bromide ion and the water molecule are engaged in hydrogen bonding (Figure S7).…”

3-(1H-Pyrrol-2-yl)-1H-pyrazole forms an unusual hydrogen-bonded two-dimensional (3,4)-connected net

“…A pyrazole ring can therefore bind a metal cation and anion simultaneously, and several 1H-pyrazole complexes have proved to be useful hosts for inorganic anions (Pé rez & Riera, 2008). As part of our own investigations of the supramolecular chemistry of N-H pyrazole derivatives (Renard et al, 2002(Renard et al, , 2006Liu et al, 2004;Pask et al, 2006;Jones et al, 2006), we have achieved the first synthesis of the title compound, (I). Given the well known ability of pyrrole derivatives to act as anion hosts in their own right , the combination of pyrrole and pyrazole groups in (I) makes it a potentially useful reagent for supramolecular chemistry.…”