Investigating the Potential of Flexible and Pre-Organized Tetraamide Ligands to Encapsulate Anions in One-Dimensional Coordination Polymers: Synthesis, Spectroscopic Studies and Crystal Structures

Crystals

卷:11

MohdSukeri Mohd Yusof¹  NurShuhaila Haryani Haris¹  Maisara Abdul Kadir¹  Nafisah Mansor¹  ChristopherJ. Sumby² 

[1] Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia;

[2] School of Physical Sciences, Centre for Advanced Nanomaterials, The University of Adelaide, Adelaide, SA 5005, Australia;

关键词: synthesis;    crystal;    coordination polymer;    tetraamide;    pre-organized amide;    framework;   

DOI  :  10.3390/cryst11010077

来源: DOAJ

【 摘 要 】

The synthesis of amide-based molecules, possessing pre-organized structures, has received significant attention due to their potential applications as molecular receptors and as components of nanomaterials. In this study, four extended tetraamide ligands incorporating ethylene and propylene spacers, namely 1,2-bis[N,N′-6-(3-pyridylmethylamido)pyridyl-2-carboxyamido]ethane (L1), 1,2-bis[N,N′-6-(4-pyridylmethylamido)pyridyl-2-carboxyamido]ethane (L2), 1,2-bis[N,N′-6-(3-pyridylmethylamido)pyridyl-2-carboxyamido]propane (L3) and 1,2-bis[N,N′-6-(4-pyridylmethylamido)pyridyl-2-carboxyamido]propane (L4), were successfully synthesized. Further, reaction of L2 and L4, incorporating pendant 4-pyridyl donors as the metal coordinating sites, with cadmium salts, produced two close-packed one-dimensional coordination polymers, {[Cd₃(L2)₄(H₂O)₁₀](NO₃)₆·12H₂O·CH₃OH}_n and {[Cd(SO₄)(L4)(H₂O)₂]·4H₂O·CH₃OH}_n. X-ray crystallography reveals that the flexible tetraamide ligands fold upon themselves in the coordination polymer structure. As a consequence, the anion pocket in {[Cd(SO₄)(L4)(H₂O)₂]·4H₂O·CH₃OH}_n incorporating the ligand with the propylene spacer was blocked from encapsulating charge-balancing anions, which were involved in bridging the di-cadmium units. Interestingly, a strong interaction between the 2,6-pyridine dicarboxamide moiety with the nitrate anions was found in {[Cd₃(L2)₄(H₂O)₁₀](NO₃)₆·12H₂O·CH₃OH}_n, showing potential for materials made from these ligands to serve as anion receptors.

【 授权许可】

Unknown