Characterization and crystal structure of cadmium(II) halide complexes with amino acids and their derivativesVI. The comparison of crystal structures of cadmium(II) halide complexes with three kinds of piperidine carboxylic acids

Structure characterization of a novel 3-D cadmium-halo coordination polymer linked by piperazine bridge

“…The crystallographically unique Cd1 center in 1 with an octahedral geometry is coordinated by four Br atoms and two N donors from two different piperazine molecules. The Cd-Br bond lengths in the range of 2.797(1)-2.829(1) Å (average 2.813 Å ) are slightly longer than those found in most reported cadmium-bromo complexes, basically comparable with those observed in [CdBr 2 (3-Mepyridine) 2 ] [3a] and [CdBr 2 (piperidine-3-carboxylate)] [7], but somewhat shorter than those in [8]. The Cd-N bond length is normal 2.342 Å .…”

Characterization and crystal structure of cadmium(II) halide complexes with amino acids and their derivatives: VII. Crystal structures of aquadibromo(3-aminopropanoic acid)cadmium(II), dichloro(4-aminobutanoic acid)cadmium(II), diaquabis(aminohexanoic acid)cadmium(II) tetrachlorocadmium(II), and dibromo(azetidine-3-carboxylic acid)cadmium(II)

“…This polymer chain extends in the direction of the a-axis like a twisted zigzag folding screen. This structure is similar to that of [CdCl 2 -(Hsar)] [9], [CdBr 2 (DL-Hpipe-3)] [10], and [CdCl 2 (Hpipe-4)] [10], in which two carboxyl oxygen atoms are coordinated to the identical cadmium atom. However, this structure is different from those of [CdCl 2 (L-Hhpro)] [5], [CdCl 2 -(L-Hpro)](H 2 O) [6], [CdCl 2 (L-Hpipe-3)] [7], and [CdCl 2 (LHaze-2)](H 2 O) [8].…”

“…Dichloro(4-hydroxy-L-proline)cadmium(II) [CdCl 2 (L-Hhpro)] [5], dichloro(L-proline)cadmium(II) monohydrate [CdCl 2 (L-Hpro)](H 2 O) [6], dichloro(L-piperidine 3-carboxylic acid)cadmium(II) [CdCl 2 (L-Hpipe-3)] [7], and dichloro(L-azetidine-2-carboxylic acid)cadmium(II) monohydrate [CdCl 2 (L-Haze-2)]-(H 2 O) [8] have a one-dimensional polymer bridged by chlorine atoms and a carboxyl group, like an infinite folding screen. Dichloro(N-methylglycine)cadmium(II) [CdCl 2 (Hsar)] [9], dibromo(DL-piperidine-3-carboxylic acid)cadmium(II) [CdBr 2 (DL-Hpipe-3)] [10], and dichloro(piperidine-4-carboxylic acid)cadmium(II) [CdCl 2 (Hpipe-4)] [10] have a one-dimensional polymer bridged by two halogen atoms, and in these complexes two carboxyl oxygen atoms have ligated to the same atom and have made a four-membered chelate ring. Diaquadichloro-(N,N-dimethylglycine)cadmium(II) [CdCl 2 (Hdmgly)(H 2 O) 2 ] [9] has three chlorine atoms, of which one is terminal and the other two are bridging cadmium atoms to make a polymer.…”

“…A carboxyl group bonds to a cadmium atom as a monodentate ligand. Aquachloro(DL-piperidine-2-carboxylic acid)cadmium(II) [CdCl-2 (DL-Hpipe-2)(H 2 O)] [10] has a one-dimensional polymer bridged by chlorine atoms and a carboxyl group, and has a terminal chlorine and a water molecule. The structures of [CdCl 2 (L-Hpipe-3)] [7] and [CdBr 2 (DL-Hpipe-3)] [10] are different from each other in spite of being formed with the same ligand: Hpipe.…”

Two different one-dimensional CdIIhalide coordination polymers constructed through bridging carboxylate ligands

“…Thus, the order of the Cd-Cl distances is clearly differentiated as bridging Cl > terminal Cl. In general, all the bond lengths and angles are in the normal ranges found in other Cd II compounds (Inomata et al, 2004).…”