title: Assembly of 1D, 2D and 3D lanthanum(iii) coordination polymers with perchlorinated benzenedicarboxylates: positional isomeric effect, structural transformation and ring-opening polymerisation of glycolide.
abstract: Utilizing a series of positional isomers of tetrachlorinated benzenedicarboxylic acid ligands, seven La(iii)-based coordination polymers were solvothermally synthesized and structurally characterized. Their structural dimensionalities varying from 1D double chains, to the 2D 3,4,5-connected network, to 3D 6-connected pcu topological nets are only governed by the positions of carboxyl groups on the tetrachlorinated benzene ring. A comprehensive analysis and comparison reveals that the size of the carbonyl solvent molecules (DMF, DEF, DMA, and NMP) can affect the coordination geometries around the La(iii) ions, the coordination modes of carboxylate groups, the packing arrangements, and the void volumes of the overall crystal lattices. One as-synthesized framework further shows an unprecedented structural transformation from a 3D 6-connected network to a 3D 4,5-connected net through the dissolution and reformation pathway in water, suggesting that these easily hydrolyzed lanthanide complexes may serve as precursors to produce new high-dimensional frameworks. The bulk solvent-free melt polymerisation of glycolide utilizing these La(iii) complexes as initiators has been reported herein for the first time. All complexes were found to promote the polymerization of glycolide over a temperature range of 200 to 220 °C, producing poly(glycolic acid) (PGA) with a molecular weight up to 93,280. Under the same experimental conditions, the different catalytic activities for these complexes may result from their structural discrepancy.
authors.affiliation: School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 20094, PR China. chenqunjpu@yahoo.com and School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: Sheng-Chun
authors.initials: SC
authors.lastname: Chen
authors.affiliation: School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: An-Qi
authors.initials: AQ
authors.lastname: Dai
authors.affiliation: College of Chemistry, Chongqing Normal University, Chongqing 401331, PR China. kunlin@cqnu.edu.cn.
authors.forename: Kun-Lin
authors.initials: KL
authors.lastname: Huang
authors.affiliation: School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Zhang
authors.affiliation: School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: Ai-Jun
authors.initials: AJ
authors.lastname: Cui
authors.affiliation: School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: He
authors.affiliation: School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 20094, PR China. chenqunjpu@yahoo.com and School of Petrochemical Engineering, Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, Changzhou University, Changzhou 213164, PR China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Chen
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006016:Glycolates / Q000737:chemistry*; D054879:Halogenation; D007811:Lanthanum / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011100:Polyglycolic Acid / Q000138:chemical synthesis / Q000737:chemistry*; D058105:Polymerization; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D002264:Carboxylic Acids; D006016:Glycolates; D012997:Solvents; D014867:Water; C031149:glycolic acid; D011100:Polyglycolic Acid; D007811:Lanthanum