Structural Diversity of Cadmium(II) Coordination Polymers Induced by Tuning the Coordination Sites of Isomeric Ligands was written by Liu, Bo;Zhou, Hui-Fang;Hou, Lei;Wang, Jian-Ping;Wang, Yao-Yu;Zhu, Zhonghua. And the article was included in Inorganic Chemistry in 2016.Reference of 89978-52-9 This article mentions the following:
When the coordination sites of ligands were shifted, the solvothermal reactions of four positional isomeric asym. phenylpyridine-dicarboxylic acids with Cd(NO3)2 generated four new coordination polymers, [Cd(L1)(DMF)3]·DMF·H2O (1), [H2NMe2]2[Cd(L2)2]·3DMF·H2O (2), [Cd(L3)(H2O)2] (3), and [Cd(L4)]·1.5DMF (4), where H2L1 = 2-(3′-carboxylphenyl)isonicotinic acid, H2L2 = 2-(4′-carboxylphenyl)isonicotinic acid, H2L3 = 5-(3′-carboxylphenyl)nicotic acid, and H2L4 = 2-(3′-pyridyl)terephthalic acid. 1 Shows a rare 2D fabric structure. 2 Discloses a grid-layer structure with heterochiral helical chains and in which three sets of layers stack in different directions, affording an unprecedented 2D + 2D + 2D → 3D polycatenating framework with 3D intersecting porous systems. 3 Also displays a 2D layer possessing strong intralayer π···π interactions and interlayer H bonds. 4 Contains a rare Cd2(COO)4 paddle-wheel unit and forms a 3D framework with 1D open channels. The carboxyl and pyridyl groups of the positional isomeric H2L1-H2L4 ligands show distinct bridging fashions, which gives versatile architectures of 1–4, and their effects on the crystal structures are discussed. 1–4 Reveal solid-state photoluminescence stemming from intraligand charge transfer. 2 And 4 show high selectivity for CO2 over CH4, but with different CO2 adsorption enthalpies. Grand canonical Monte Carlo simulations identified the multiple adsorption sites in 2 for CO2. In the experiment, the researchers used many compounds, for example, Ethyl 2-bromoisonicotinate (cas: 89978-52-9Reference of 89978-52-9).
Ethyl 2-bromoisonicotinate (cas: 89978-52-9) belongs to pyridine derivatives. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1.The molecular electric dipole moment is 2.2 debyes. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase and 140.4 kJ·mol−1 in the gas phase. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Reference of 89978-52-9