TY - JOUR
T1 - Structural variability of Cd(II) and Co(II) mixed-ligand coordination polymers
T2 - Effect of ligand isomerism and metal-to-ligand ratio
AU - Cui, Feng Yun
AU - Huang, Kun Lin
AU - Xu, Yan Qing
AU - Han, Zhan Gang
AU - Liu, Xi
AU - Chi, Ying Nan
AU - Hu, Chang Wen
PY - 2009
Y1 - 2009
N2 - A series of seven mixed-ligand coordination polymers, namely {[Cd 4(H2L1)4(suc)4]·3H 2O}n (1), {[Cd4(H2L1) 3(suc)4]·5H2O}n (2), {[Cd2(HL1)2(suc)]·8H2O}n (3), {[Cd(H2L2)(suc)]·3H2O}n (4), {[Cd(H2L3)(suc)]·3H2O}n (5), {[Co(H 2L1)(chdc)(H2O)]·H2O}n (6), {[Co(H2L2)(chdc)(H2O)]}n (7) have been produced by the reaction of three 2-amino-4,6-dipyridylpyrimidine isomers (H 2L1, H2L2, H2L3) and secondary ligand 1,4-succinic acid (H2suc) or 1,4-cyclohexanedicarboxylic acid (H 2chdc) with Cd(II) and Co(II) salts under hydrothermal conditions. All these compounds have been structurally determined by elemental analysis, IR and single-crystal X-ray diffraction. The three isomers are introduced in a mixed-ligand system for the first time. For the H2L1-H 2suc-Cd(II) system, it is found that the structures of compounds 1-3 exhibiting a 1-D double-chain, a rare 1-D quadruple nano-chain and a 2-D network with (6,3) topology, respectively, are influenced by the ratio of metal-to-ligand. When H2L2 and H2L3 were used instead of H2L1, two 1-D chains (compounds 4 and 5) were obtained. Although they have the same molecular formula and structure motif, their supramolecular networks constructed by hydrogen-bondings and π-π stacking interactions are different. When H2L1 and H2L2 were introduced into the Co(NO3)2-H2chdc system, compounds 6 and 7 were successfully isolated, and display a zigzag chain and a helical chain, respectively. Interestingly, the cis- and trans-conformations of H 2chdc were separated completely in the two compounds. The results reveal that both the coordination structure and the supramolecular assembly could be directed by the ligand isomers. Furthermore, several intriguing water clusters have been observed in these mixed-ligand compounds, such as a novel (H2O)10 cluster in 2, a 2-D water net formed by (H 2O)8 clusters in 3, a 1-D undulated water chain in 4 and a chair-shaped (H2O)6 cluster in 5. The solid-state properties of compounds 1-7 such as thermal stability and fluorescence have also been investigated.
AB - A series of seven mixed-ligand coordination polymers, namely {[Cd 4(H2L1)4(suc)4]·3H 2O}n (1), {[Cd4(H2L1) 3(suc)4]·5H2O}n (2), {[Cd2(HL1)2(suc)]·8H2O}n (3), {[Cd(H2L2)(suc)]·3H2O}n (4), {[Cd(H2L3)(suc)]·3H2O}n (5), {[Co(H 2L1)(chdc)(H2O)]·H2O}n (6), {[Co(H2L2)(chdc)(H2O)]}n (7) have been produced by the reaction of three 2-amino-4,6-dipyridylpyrimidine isomers (H 2L1, H2L2, H2L3) and secondary ligand 1,4-succinic acid (H2suc) or 1,4-cyclohexanedicarboxylic acid (H 2chdc) with Cd(II) and Co(II) salts under hydrothermal conditions. All these compounds have been structurally determined by elemental analysis, IR and single-crystal X-ray diffraction. The three isomers are introduced in a mixed-ligand system for the first time. For the H2L1-H 2suc-Cd(II) system, it is found that the structures of compounds 1-3 exhibiting a 1-D double-chain, a rare 1-D quadruple nano-chain and a 2-D network with (6,3) topology, respectively, are influenced by the ratio of metal-to-ligand. When H2L2 and H2L3 were used instead of H2L1, two 1-D chains (compounds 4 and 5) were obtained. Although they have the same molecular formula and structure motif, their supramolecular networks constructed by hydrogen-bondings and π-π stacking interactions are different. When H2L1 and H2L2 were introduced into the Co(NO3)2-H2chdc system, compounds 6 and 7 were successfully isolated, and display a zigzag chain and a helical chain, respectively. Interestingly, the cis- and trans-conformations of H 2chdc were separated completely in the two compounds. The results reveal that both the coordination structure and the supramolecular assembly could be directed by the ligand isomers. Furthermore, several intriguing water clusters have been observed in these mixed-ligand compounds, such as a novel (H2O)10 cluster in 2, a 2-D water net formed by (H 2O)8 clusters in 3, a 1-D undulated water chain in 4 and a chair-shaped (H2O)6 cluster in 5. The solid-state properties of compounds 1-7 such as thermal stability and fluorescence have also been investigated.
UR - http://www.scopus.com/inward/record.url?scp=72449174358&partnerID=8YFLogxK
U2 - 10.1039/b907606a
DO - 10.1039/b907606a
M3 - Article
AN - SCOPUS:72449174358
SN - 1466-8033
VL - 11
SP - 2757
EP - 2769
JO - CrystEngComm
JF - CrystEngComm
IS - 12
ER -