Lamellar and Three‐Dimensional Hybrid Compounds Formed by Cyclohexene‐ and Cyclohexanedicarboxylates of Pb, La, and Cd

Abstract

To establish factors that determine the formation of three-dimensional hybrid structures of metal dicarboxylates involving metal-oxygen-metal linkages, we have investigated metal dicarboxylates derived from 1,2-cyclohexene as well as 1,2-, 1,3-, and 1,4-cyclohexane dicarboxylic acids. Thus, we have synthesized a 1,2-cyclohexenedicarboxylate of Cd, [Cd(1,2-CHeDC)(H2O)] (I), a 1,2-cyclohexanedicarboxylate of Pb, [Pb(1,2-CHDC)] (II), and three 1,4-cyclohexanedicarboxylates of La [La2(1,4-CHDC)3(H2O)4] (III), [La3(1,4-HCHDC)2(1,4-CHDC)5(H2O)2].H2O (IV) and [La2(1,4-CHDC)3(H2O)].2.5 H2O (V) under hydrothermal conditions and determined their structures. A mixed dicarboxylate involving both 1,3- and 1,4-cyclohexenedicarboxylates of Pb, [Pb3O(1,3-CHDC)(1,4-CHDC)].0.5 H2O (VI) and a 1,4-cyclohexanedicarboxylate of Pb, [Pb(6)O(2)(1,4-CHDC)3(1,4-HCHDC)2], have also been synthesized and characterized. While the 1,2-dicarboxylates have layered structures, the 1,4-dicarboxylates and the mixed dicarboxylates possess three-dimensional structures. Interestingly, both the 1,2 and 1,4-dicarboxylates are true hybrid compounds composed of infinite M-O-M linkages. The equatorial-equatorial (e,e) conformation is adopted commonly in all these compounds, although less stable conformations are encountered occasionally. The formation of the layered and the three-dimensional structures can be understood based on the relative disposition of the two carboxylic groups, the 1,4-isomer favoring the three-dimensional structure. Based on the results of the present study along with the available literature, we conclude that in order to obtain three-dimensional hybrid structures with metal-oxygen-metal networks, it appears necessary to make use of the 1,4-cyclohexanedicarboxylic acid.

Hydrothermal synthesis and crystal structure of a luminescent 3D lead(II) coordination polymer [Pb(4-cca)]n (4-cca=4-carboxycinnamate)

“…On the other hand, some Pb(II) carboxylate compounds have exhibited various luminescent properties [14][15][16]. Although there are also some examples related to Pb(II) complexes of dicarboxylates with common spacers such as 1,4-BDC [3,17,18], À O 2 C-ðCH 2 Þ n -CO À 2 (n = 2-4) [18], 1,2-cyclohexanedicarboxylate (1,2-CHDC) and 1,3-CHDC [19], 1,4-naphthalenedicarboxylate (NDC) [14], the Pb(II) complexes of dicarboxylates with other spacers are still limited in number. 4-Carboxycinnamic acid (4-H 2 cca) is an uncommon dicarboxylic acid with a rigid and relatively long -Ph-CH@CH-spacer.…”

Novel CdII coordination polymers (1-D, 2-D to 3-D) constructed from 1,2-cyclohexanedicarboxylate and various bipyridyl ligands

“…1). The coordination mode for two carboxylates in 1,2-chdc is the asymmetric chelating (g 1 :g 1 ) [30][31][32][33][34][35]48]. The intramolecular hydrogen bond between water hydrogen atom and next carboxylate oxygen atom in a chain makes the one-dimensional chain structure stronger (green dotted lines in Fig.…”

“…Recently, coordination polymers with flexible multicarboxylates, such as 1,4-cyclohexanedicarboxylate (1,4-chdc) [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], 1,3-cyclohexanedicarboxylate (1,3-chdc) [23], 1,2,3,4,5,6-cyclohexanehexacarboxylate (chhc) [24][25][26][27], and cyclohexane-1,2,4,5-tetracarboxylate (cht) [28], which can control conformation and configuration conversion in coordination networks, have been synthesized and intensively studied [29]. Compare to metal-(1,4-chdc) complexes, few metal complexes with 1,2-cyclohexanedicarboxylate (1,2-chdc) have been reported in the literature [30][31][32][33][34][35].…”

Preparation, characterization, crystal structures and catalytic oxidation activities of two transition metal complexes of an N-heterocyclic pincer ligand

“…The pyridines have a high tendency to span two metal ions as N,N 0 -bridging ligands [6]. Such bridging ligands can give compact and highly stable grid complexes with a variety of 3d transition metals [7][8][9][10]. Meanwhile, polydentate benzene pyrazole ligands can be classified as benzene-linked di-pyrazolyl, benzene-linked tetra-pyrazolyl and benzene-linked hexa-pyrazolyl.…”