Synthesis,Crystal Structure And Properties Of The Novel Coordination Polymer With Carboxylic Acid As Ligands

Research on coordination polymers is very important in inorganic chemistry.At the same time,it is widely used in many fields such as Catalysis,electrochemistry,biosensing,molecular recognition and separation due to its unique structure and excellent properties.The study of novel structural coordination polymers has always been the hotspot in coordination chemistry.In this paper,7 kinds of coordination polymers have been synthesized by transition metal ions,and 5 kinds of coordination polymers for the first time.The specific research content is as follows:?1?Two kinds of coordination polymers,denoted as[Co?DPC?·?phen?·H₂O]·2H₂O?C1?and[Ni?DPC?·?phen?·H₂O]·2H₂O?C2?,are successfully synthesized through hydrothermal method by using 2,6-pyridinedicarboxylic acid?DPC?and1,10-phenanthroline?phen?as ligands and characterized by Fourier transform infrared spectroscopy?FT-IR?,X-ray single crystal diffraction?SXRD?,Differential scanning calorimetry?DSC?and so on.At the same time,the molar heat capacities of the two kinds of coordination polymers are measured in the temperature range of 203 to 311 K using DSC method,and their thermodynamic data are obtained.The molar heat capacities of C1and C2 are 443.74 and 492.70 J·mol^-1·K^-1at 298.15 K,respectively.?2?Three kinds of novel coordination polymers have been successfully fabricated for the first time through hydrothermal method by using 2,6-pyridinedicarboxylic acid?DPC?and 1,10-phenanthroline?phen?as ligands.Among the three materials,[Ni?phen?₂·Co?phen?₂·2Co?DPC?₂·4H₂O]·13H₂O?C3?pertains to cobalt-nickel binary layered materials,[Co?phen?₃·Fe?phen?₃·2Co?DPC?₂·2Fe?DPC?₂]·2H₂O?C4?belongs to cobalt-iron binary layered materials and[Co?DPC?₂·Cu?DPC?₃·2Cu?Phen?₂·4H₂O]·14H₂O?C5?is the property of cobalt-copper binary bulk crystal materials,respectively.These coordination polymers have been characterized by FT-IR,SXRD,elemental analysis?EA?,etc.According to the analysis of X-ray single crystal diffraction data,the coordination polymer C3 belongs to triclinic system,space group P1 with Mr=1922.98,a=10.0585?18?nm,b=14.684?3?nm,c=14.931?3?nm,?=74.078?6?^°,?=78.399?6?^°,?=75.279?6?^°,V=2030.5?7?nm³,Z=1;the coordination polymer C4 belongs to triclinic system,space group P1 with Mr=2782.43,a=13.1026?9?nm,b=14.2989?9?nm,c=18.2455?10?,?=105.117?2?°,?=103.177?2?°,?=100.122?2?°,V=3111.0?3?3,Z=1;the coordination polymer C5 belongs to triclinic system,space group P1 with Mr=1955.10,a=10.0956?5?nm,b=14.6914?9?nm,c=14.9844?9?nm,?=73.776?2?^°,?=78.734?2?^°,?=74.945?2?^°,V=2042.6?2?³,Z=1.A simple and efficient way to synthesize single crystal of binary metal coordination polymers is proposed in this work.?3?Two kinds of transition metal coordination polymers called[2Co?pzda?·?phen?·2H₂O]·2H₂O?C6?and[2Ni?pzda?·?phen?·2H₂O]·2H₂O?C7?have been synthesized through the hydrothermal method with 2,6-pyrazine dicarboxylic acid?pzda?and 1,10-phenanthroline?phen?as ligands and characterized by FT-IR,SXRD,EA,etc.The SXRD analytic results indicate that the both coordination polymers belong to triclinic system with P-1 space groups and their crystal structure are similar as[Co?DPC?·?phen?·H₂O]·2H₂O.And the structures of the two coordination polymers form a three-dimensional framework by hydrogen bonding,and there is a strong?-?stacking effect between the heterocycles.Further study shows that there are still C-H···N hydrogen bonds in the synthesized crystal.