Mixtures obtained by reacting trans-(±)-1,2-diaminocyclohexane with acetylacetone in the presence of simple cobalt(II) salts

Abstract

In the absence of a metal ion, racemic trans-1,2-diaminocyclohexane (trans-(9 )DCH) reacts with acetylacetone (acacH) (1:2.5 mole ratio) to form the bisoxoenamine condensation product, boe (1). (9) co-crystallise. Complexes 1, 5, 7, 8 and 9 were characterised using X-ray crystallography. The major difference between using CoCl 2 ·6H 2 O and Co(ClO 4 ) 2 ·6H 2 O in reactions involving ( 9)DCH and acacH is that no DCH/acacH condensation products are identified in the product mixtures when the perchlorate salt is employed.

Phenylene‐bridged β‐Ketoiminate Dilanthanide Aryloxides: Synthesis, Structure, and Catalytic Activity for Addition of Amines to Carbodiimides

“…Compound 1 was comprehensively characterized by NMR spectroscopy, IR spectroscopy as well as elemental analysis. 1 H NMR spectrum of 1 reveals the methine proton of the ketoiminate backbone at δ = 5.20 ppm, which is consistent with analogous bridged bis(β‐ketimine) ligand linked by 4,4′‐methylene‐bis(2–6‐diisopropylaniline),6b and diaminocyclohexane 6a,6c…”

Silver(I) and mercury(II) complexes with N,N′-bis(acetylacetone)-1R,2R-diaminocyclohexane ligands exhibiting three different coordination modes

“…X-ray structural analysis revealed that 3 is a 1D coordination polymer (see Fig. 4), crystallized in the monoclinic space group C2/c, and straddles the (11), O(3)À Ag(1)/Ag(1A) 80.35 (10). Symmetry code: a) Àx þ 1, Ày þ 1, Àz þ 2; b) Àx þ 3 / 2 , Ày, z.…”

“…The ligand N,N 0 -bis(acetylacetone)-1R,2R-diaminocyclohexane (L) was synthesized according to the literature procedure [10]. NMR spectra were recorded on a Bruker ALX 300 spectrometer operating at 300 MHz for 1 H. Chemical shifts (d, ppm) were reported with reference to SiMe 4 ( 1 H).…”

“…In contrast to welldocumented enantiopure ligands to introduce chirality into framework complexes, the chiral Schiff bases as monoanionic ketiminato or linked dianionic ketiminato ligands have received less attention [8,9]. The typical chiral Schiff base ligand, N,N 0 -bis (acetylacetone)-1R,2R-diaminocyclohexane (L), easily formed from the condensation of trans-1R,2R-diaminocyclohexane with two equivalents of acetylacetone (acacH) in hot ethanol solution [10]. It is interesting to note that this chiral Schiff base ligand L is of two substituted imines, two open ends on the oxygen sites, and higher acidity of the b-hydrogen atoms due to the ketiminato backbone [9,10].…”

“…The typical chiral Schiff base ligand, N,N 0 -bis (acetylacetone)-1R,2R-diaminocyclohexane (L), easily formed from the condensation of trans-1R,2R-diaminocyclohexane with two equivalents of acetylacetone (acacH) in hot ethanol solution [10]. It is interesting to note that this chiral Schiff base ligand L is of two substituted imines, two open ends on the oxygen sites, and higher acidity of the b-hydrogen atoms due to the ketiminato backbone [9,10]. It has been reported that the new helical metal coordination polymer [CdI 2 (m-L)] n was obtained from the 1:1 interaction of the diastereopure Schiff bases L with CdI 2 [11].…”